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accumulation or depletion as the cause discussion
Posted by gregg
|
gregg
accumulation or depletion as the cause discussion October 25, 2003 05:37AM |
we started the thread a while back re: the regularity of intervals of the bouts that some of us have - regardless of what we do. pc and others shared their opinion whether it was an accumulation of "something" or a depletion of "something" that causes the bouts of afib. and that one or the other happens with regularity.
i now believe in the accumulation theory based on my diary for the past year+. this is based on my circumstance of having palpatations of missed beats, irreg. etc. when i go to bed (go horizontal regardless if lay on my back, lie on the right or left side) which thank goodness does not always progress to full bouts or else i would never get any sleep. (as an aside, if anyone else has this problem, and has come up with a solution, please, please let me know what you found).
what i have found is that whenever i go into afib on those expected days (as opposed to happening in the middle of the night), when i go to bed and lay down, i get absolutely no palps of any type - the heart is calm, calm, calm. i am thinking that whatever is causing my afib has been used up during the bout and is starting a new cycle accumulation process. but once used up, the world is good.
the question i'm trying to answer now is what is that "something" that is accumulating. pc, is this theory still on your radar?
i now believe in the accumulation theory based on my diary for the past year+. this is based on my circumstance of having palpatations of missed beats, irreg. etc. when i go to bed (go horizontal regardless if lay on my back, lie on the right or left side) which thank goodness does not always progress to full bouts or else i would never get any sleep. (as an aside, if anyone else has this problem, and has come up with a solution, please, please let me know what you found).
what i have found is that whenever i go into afib on those expected days (as opposed to happening in the middle of the night), when i go to bed and lay down, i get absolutely no palps of any type - the heart is calm, calm, calm. i am thinking that whatever is causing my afib has been used up during the bout and is starting a new cycle accumulation process. but once used up, the world is good.
the question i'm trying to answer now is what is that "something" that is accumulating. pc, is this theory still on your radar?
|
Fran
Re: accumulation or depletion as the cause discussion October 25, 2003 05:46AM |
|
J. Pisano
Re: accumulation or depletion as the cause discussion October 25, 2003 06:06AM |
Fran,
Can you expound on your experience of free glutamate build up....I know that it is an exitotoxin, but thought that the glutamates usually effect the neruologic states....I know that many of these toxins are effected by calcium, as a bad thing. What is your take on how the actually effect the ANS?
Thanks,
Joe
Can you expound on your experience of free glutamate build up....I know that it is an exitotoxin, but thought that the glutamates usually effect the neruologic states....I know that many of these toxins are effected by calcium, as a bad thing. What is your take on how the actually effect the ANS?
Thanks,
Joe
|
Fran
Re: accumulation or depletion as the cause discussion October 25, 2003 07:56AM |
I posted this in the conference room a while back Managing Afib Are we getting close?... and with PC's reply
[nips.physiology.org]
A third action of the postinspiratory neurons
would be to augment glutamatergic neurotransmission by activating nicotinic receptors that facilitate postsynaptic non-NMDA
receptors in cardiac vagal neurons. These latter two effects could constitute mechanisms by which respiratory
inputs gate, or facilitate, the baroreflex during postinspiration.
In summary, during the last 5 years there has been considerable progress in our understanding of the voltage-, Ca-,
and ligand-gated channels, synaptic pathways, transmitters, and receptors involved in the central control of cardiac
vagal activity. It is apparent that cardiac vagal neurons are inherently silent and depend on excitatory synaptic input for
their activity. Synaptic inputs to cardiac vagal neurons include NTS neurons, which activate both NMDA and non-NMDA
receptors in cardiac vagal neurons. It is also likely that postinspiratory cholinergic neurons activate postsynaptic
nicotinic receptors and directly excite these neurons, which may be a mechanism responsible for respiratory sinus
arrhythmia. Postinspiratory cholinergic neurons also likely activate presynaptic nicotinic receptors on glutamatergic
terminals, which could facilitate, or gate, the baroreflex during postinspiration. However, much work is still needed,
especially investigations concerning the presynaptic and postsynaptic receptors activated upon stimulation of identified
synaptic pathways to cardiac vagal neurons and alterations in these receptors and channels during pathological
disease states. It is hoped that a further understanding of the functional importance and pharmacological properties of
presynaptic and postsynaptic receptors that determine cardiac vagal activity in the brain stem may allow us to identify
agents that can reduce cardiac vagal activity in pathological conditions with abnormally low heart rates and cardiac
function, such as SIDS, as well as increase vagal cardiac activity and reduce the fatality associated with cardiac
hyperexcitability.
This to me says Free Glutamate initiated LAF stems from the brain, and with your input from the CNS, not the ANS.
Now I know at this point it is looking like glutamate does not directly affect the heart muscle. But the fact that they use
calcium channel blockers for AF, and glutamate is a calcium channel opener, it seems to me they should be looking to
see if there are glutamate receptors in the heart. It was only recently they found them in the breast. No one will know
until someone looks. I'm not asking you to answer this. It is part of what I started with - and am left with.
Fran
PS. I discover that cardiac vagal neurons are found in the "nucleus ambiguus (NA) and the dorsal motor nucleus of the
vagus (DMNX)" Now to find a diagram
[www.annalsnyas.org]
Very good, Fran.
You now know more neuroanatomy than 99% of MDs. The nucleus ambiguus and the DMNX are the two arms of the
vagus nerve about which I've posted in the past (see last years post on RSA=respiratory sinus arrhythmia and why
swallowing can trigger AF). The former controls HRV (which we can control ourselves voluntarily to some extent by
varying our breathing) and the latter controls heart period variability, i.e., slower rate at night and higher during the day
independent of what we're doing.
The nucleus tractus solitarius (NTS) in the medulla oblongata (part of the brainstem) is the collection of ganglion cells
that receive via their axons the messages from the stretch fibers in the lung and these then trigger the ganglion cells in
the NA (via glutamate) which send signals from the medulla to the heart (as the vagus nerve). NTS are presynaptic
and NA are postsynaptic. This is my understanding and I hope someone that knows more than I will speak up if this is
incorrect.
Your comments about Ca channel blockers are very reasonable. The hooker is that Ca channel blockers are needed in
any cell that sends signals or waves. It's an electrical phenomenon in both nerves and muscles that allows them to
function as they do. However, only nerves have neurotransmitters. Then you get into the difference between a
neurotransmitter (a kind of localized hormone) and a circulating hormone. Perhaps glutamate could do both.
I won't give up on you Fran so you can't forgive me.
PC
And here is a bit of background. The whole article is well worth reading.
[smart-drugs.net]
EXCITOTOXICITY: THE BACKGROUND FACTORS
From this brief discussion of the mechanisms of NMDA-glutamate excitotoxicity, it should be clear that there are 5 main conditions which allow glutamate to shift from neurotransmitter to excitotoxin:
1) inadequate neuronal ATP levels (whatever the cause);
2) inadequate neuronal levels of magnesium, the natural, non-drug calcium channel blocker;
3) high inflammatory prostaglandin / leukotriene levels (caused by excessive glutamate-NMDA stimulated calcium invasion);
4) excessive free radical formation (caused by prostaglandin / leukotriene formation and/or insufficient intracellular antioxidants/free radical scavengers;
5) inadequate removal of glutamate from the extracellular (synaptic) space back into neurons or into astrocytes.
Addressing each of these conditions will provide appropriate nutritional/life extension drug strategies to minimize excitotoxicity.
It is claimed that even if dietary MSG/aspartame significantly raise blood levels of glutamate and aspartate, the brain will not receive any extra glutamate/aspartate due to the protective blood-brain barrier. (2,7) However, there are many reasons why this claim is false. The animal experiments cited to back this assertion are usually acute studies - that is, a single test dose of MSG or aspartame is given, and no significant elevation of brain glutamate or aspartate is found. (2) Yet humans eating MSG/aspartame-laced foods and drinks don't just get a single daily dose. Those who consume large quantities of packaged, processed, or restaurant foods frequently imbibe MSG/aspartame from breakfast to bedtime snack, even drinking aspartame-sweetened flavored waters between meals. Toth and Lajtha found that when they gave mice and rats aspartic acid or glutamate, either as single amino acids or as liquid diets, over a long period of time (days), brain levels of these supposedly blood-brain barrier-excluded excitotoxins rose significantly - aspartic acid by 61%, glutamate by 35%. (20)
To further worsen matters, humans concentrate MSG in their blood 5 times higher than mice from a comparable dose, and maintain the higher blood level longer than mice. .....
Yet another issue that makes the blood-brain barrier defense of MSG/aspartame irrelevant is brain glucose transport. Glucose is the primary fuel the brain uses to generate its ATP energy. Continual adequate brain ATP levels are needed, as noted earlier, to prevent glutamate/aspartate from shifting from neurotranmitters to excitotoxins. ...
[Hypoglycemia a known phenomena in many Afibbers effectively reduces the BBB]
Yet when the single amino MSG is rapidly absorbed (especially in solution - e.g. soups, sauces and gravies), not requiring digestion, human and animal experiments show rapid rises in glutamate, 5 to 20 times normal blood levels (2). Aspartame is a dipeptide - a union of 2 aminos- and there exist special di-and tripeptide intestinal absorption pathways that allow rapid and efficient absorption (21). The dipeptides are then separated into free aminos, and as with free MSG there will be a rapid rise in blood aspartate. Thus the characteristics of food-bound glutamate/aspartate and MSG/aspartame are completely different. The phenomenon of excitotoxicity can occur even if you never use MSG/aspartame, since neurons can produce their own glutamate/aspartate.
Hope that helps
Fran
[nips.physiology.org]
A third action of the postinspiratory neurons
would be to augment glutamatergic neurotransmission by activating nicotinic receptors that facilitate postsynaptic non-NMDA
receptors in cardiac vagal neurons. These latter two effects could constitute mechanisms by which respiratory
inputs gate, or facilitate, the baroreflex during postinspiration.
In summary, during the last 5 years there has been considerable progress in our understanding of the voltage-, Ca-,
and ligand-gated channels, synaptic pathways, transmitters, and receptors involved in the central control of cardiac
vagal activity. It is apparent that cardiac vagal neurons are inherently silent and depend on excitatory synaptic input for
their activity. Synaptic inputs to cardiac vagal neurons include NTS neurons, which activate both NMDA and non-NMDA
receptors in cardiac vagal neurons. It is also likely that postinspiratory cholinergic neurons activate postsynaptic
nicotinic receptors and directly excite these neurons, which may be a mechanism responsible for respiratory sinus
arrhythmia. Postinspiratory cholinergic neurons also likely activate presynaptic nicotinic receptors on glutamatergic
terminals, which could facilitate, or gate, the baroreflex during postinspiration. However, much work is still needed,
especially investigations concerning the presynaptic and postsynaptic receptors activated upon stimulation of identified
synaptic pathways to cardiac vagal neurons and alterations in these receptors and channels during pathological
disease states. It is hoped that a further understanding of the functional importance and pharmacological properties of
presynaptic and postsynaptic receptors that determine cardiac vagal activity in the brain stem may allow us to identify
agents that can reduce cardiac vagal activity in pathological conditions with abnormally low heart rates and cardiac
function, such as SIDS, as well as increase vagal cardiac activity and reduce the fatality associated with cardiac
hyperexcitability.
This to me says Free Glutamate initiated LAF stems from the brain, and with your input from the CNS, not the ANS.
Now I know at this point it is looking like glutamate does not directly affect the heart muscle. But the fact that they use
calcium channel blockers for AF, and glutamate is a calcium channel opener, it seems to me they should be looking to
see if there are glutamate receptors in the heart. It was only recently they found them in the breast. No one will know
until someone looks. I'm not asking you to answer this. It is part of what I started with - and am left with.
Fran
PS. I discover that cardiac vagal neurons are found in the "nucleus ambiguus (NA) and the dorsal motor nucleus of the
vagus (DMNX)" Now to find a diagram
[www.annalsnyas.org]
Very good, Fran.
You now know more neuroanatomy than 99% of MDs. The nucleus ambiguus and the DMNX are the two arms of the
vagus nerve about which I've posted in the past (see last years post on RSA=respiratory sinus arrhythmia and why
swallowing can trigger AF). The former controls HRV (which we can control ourselves voluntarily to some extent by
varying our breathing) and the latter controls heart period variability, i.e., slower rate at night and higher during the day
independent of what we're doing.
The nucleus tractus solitarius (NTS) in the medulla oblongata (part of the brainstem) is the collection of ganglion cells
that receive via their axons the messages from the stretch fibers in the lung and these then trigger the ganglion cells in
the NA (via glutamate) which send signals from the medulla to the heart (as the vagus nerve). NTS are presynaptic
and NA are postsynaptic. This is my understanding and I hope someone that knows more than I will speak up if this is
incorrect.
Your comments about Ca channel blockers are very reasonable. The hooker is that Ca channel blockers are needed in
any cell that sends signals or waves. It's an electrical phenomenon in both nerves and muscles that allows them to
function as they do. However, only nerves have neurotransmitters. Then you get into the difference between a
neurotransmitter (a kind of localized hormone) and a circulating hormone. Perhaps glutamate could do both.
I won't give up on you Fran so you can't forgive me.
PC
And here is a bit of background. The whole article is well worth reading.
[smart-drugs.net]
EXCITOTOXICITY: THE BACKGROUND FACTORS
From this brief discussion of the mechanisms of NMDA-glutamate excitotoxicity, it should be clear that there are 5 main conditions which allow glutamate to shift from neurotransmitter to excitotoxin:
1) inadequate neuronal ATP levels (whatever the cause);
2) inadequate neuronal levels of magnesium, the natural, non-drug calcium channel blocker;
3) high inflammatory prostaglandin / leukotriene levels (caused by excessive glutamate-NMDA stimulated calcium invasion);
4) excessive free radical formation (caused by prostaglandin / leukotriene formation and/or insufficient intracellular antioxidants/free radical scavengers;
5) inadequate removal of glutamate from the extracellular (synaptic) space back into neurons or into astrocytes.
Addressing each of these conditions will provide appropriate nutritional/life extension drug strategies to minimize excitotoxicity.
It is claimed that even if dietary MSG/aspartame significantly raise blood levels of glutamate and aspartate, the brain will not receive any extra glutamate/aspartate due to the protective blood-brain barrier. (2,7) However, there are many reasons why this claim is false. The animal experiments cited to back this assertion are usually acute studies - that is, a single test dose of MSG or aspartame is given, and no significant elevation of brain glutamate or aspartate is found. (2) Yet humans eating MSG/aspartame-laced foods and drinks don't just get a single daily dose. Those who consume large quantities of packaged, processed, or restaurant foods frequently imbibe MSG/aspartame from breakfast to bedtime snack, even drinking aspartame-sweetened flavored waters between meals. Toth and Lajtha found that when they gave mice and rats aspartic acid or glutamate, either as single amino acids or as liquid diets, over a long period of time (days), brain levels of these supposedly blood-brain barrier-excluded excitotoxins rose significantly - aspartic acid by 61%, glutamate by 35%. (20)
To further worsen matters, humans concentrate MSG in their blood 5 times higher than mice from a comparable dose, and maintain the higher blood level longer than mice. .....
Yet another issue that makes the blood-brain barrier defense of MSG/aspartame irrelevant is brain glucose transport. Glucose is the primary fuel the brain uses to generate its ATP energy. Continual adequate brain ATP levels are needed, as noted earlier, to prevent glutamate/aspartate from shifting from neurotranmitters to excitotoxins. ...
[Hypoglycemia a known phenomena in many Afibbers effectively reduces the BBB]
Yet when the single amino MSG is rapidly absorbed (especially in solution - e.g. soups, sauces and gravies), not requiring digestion, human and animal experiments show rapid rises in glutamate, 5 to 20 times normal blood levels (2). Aspartame is a dipeptide - a union of 2 aminos- and there exist special di-and tripeptide intestinal absorption pathways that allow rapid and efficient absorption (21). The dipeptides are then separated into free aminos, and as with free MSG there will be a rapid rise in blood aspartate. Thus the characteristics of food-bound glutamate/aspartate and MSG/aspartame are completely different. The phenomenon of excitotoxicity can occur even if you never use MSG/aspartame, since neurons can produce their own glutamate/aspartate.
Hope that helps
Fran
|
Fran
Re: accumulation or depletion as the cause discussion October 25, 2003 08:41AM |
And about build up of free glutamate in lay speech - phew
[www.ideatown.com]
You or someone you know is probably suffering without even knowing that NTXAs are the real culprit. Whenever you feel your nose running or "tingling" after a meal, youve been eating NTXAs. If you have intense nightmares, sleep paralysis, or sleepless nights where, as one patient put it, your "brain just wont shut up," you are probably reacting to the NTXAs youve been eating all your life.
Once you consume an NTXA, it stays in your brain for twelve to twenty-four hours. And, if you eat NTXAs at every meal (which you probably do), your nervous system NEVER RESTS, and the negative symptoms build up day after day after day. Exhaustion, fatigue, depression, and reduced immune function are all results of this constant neurological attack."
This is maybe not so much a build up of free glutamate, but the 'dying' bodies inability to deal with it. With the excitotoxic reactions free radicals are formed and the body gets more and more toxic. Calcium gets trapped in the cells, the body becomes acid etc etc. So smaller and smaller amounts of free glutamate over time give larger and larger reactions.
This was my reaction to it. In the beginning I never knew what was causing my AF. Now it only takes a small amount of free glutamate. I have to steer well clear. I have been too scared to ever try it again - and make sure I never make mistakes.
[www.ideatown.com]
You or someone you know is probably suffering without even knowing that NTXAs are the real culprit. Whenever you feel your nose running or "tingling" after a meal, youve been eating NTXAs. If you have intense nightmares, sleep paralysis, or sleepless nights where, as one patient put it, your "brain just wont shut up," you are probably reacting to the NTXAs youve been eating all your life.
Once you consume an NTXA, it stays in your brain for twelve to twenty-four hours. And, if you eat NTXAs at every meal (which you probably do), your nervous system NEVER RESTS, and the negative symptoms build up day after day after day. Exhaustion, fatigue, depression, and reduced immune function are all results of this constant neurological attack."
This is maybe not so much a build up of free glutamate, but the 'dying' bodies inability to deal with it. With the excitotoxic reactions free radicals are formed and the body gets more and more toxic. Calcium gets trapped in the cells, the body becomes acid etc etc. So smaller and smaller amounts of free glutamate over time give larger and larger reactions.
This was my reaction to it. In the beginning I never knew what was causing my AF. Now it only takes a small amount of free glutamate. I have to steer well clear. I have been too scared to ever try it again - and make sure I never make mistakes.
|
J. Pisano
Re: accumulation or depletion as the cause discussion October 25, 2003 12:12PM |
Fran, PC,
Wow.... Now I am going to have to re-read this in print form with my cardiology and neurology books at the ready! The CNS connection, is mind boggling since we all have a common knowledge of the heart being reagulated through the ANS. But I have to agree with you if free glutamate is a calcium channel opener then why would it not effect the myocytes in the heart. Indeed!.
To understand all of this,do we have to become amateur neuroanatamists as well! Well off to it!
Joe
Wow.... Now I am going to have to re-read this in print form with my cardiology and neurology books at the ready! The CNS connection, is mind boggling since we all have a common knowledge of the heart being reagulated through the ANS. But I have to agree with you if free glutamate is a calcium channel opener then why would it not effect the myocytes in the heart. Indeed!.
To understand all of this,do we have to become amateur neuroanatamists as well! Well off to it!
Joe
|
gregg
Re: accumulation or depletion as the cause discussion October 25, 2003 01:37PM |
fran,
i didn't see this in the article but how does one negate the free glutamate (most of us are already staying away from msg), is there some food or supplement that can do this?
and while i understand the process of causing afib, how does the actual afib process deplete the free glutamate so that the build-up process begins again?
i didn't see this in the article but how does one negate the free glutamate (most of us are already staying away from msg), is there some food or supplement that can do this?
and while i understand the process of causing afib, how does the actual afib process deplete the free glutamate so that the build-up process begins again?
|
Fran
Re: accumulation or depletion as the cause discussion October 25, 2003 09:18PM |
GABA is the inhibitory neurotransmitter to free glutamate. If you go to the conference room there is a lot written about it. Unfortunately many free glutamate sensitive people have tried it but it hasn't worked. However, for some it seemed to help.
Valium and the other benzodiazapams work on the GABA receptor, so has a very similar efect. For me this is the only drug (valium) I can take without adverse reactions. However it is addictive and due to my AF seizure activity did get addicted at one point 20 years or so back. On the odd occasions when things get too much I will take a 2mg tablet - eg when my Mum died. IT certainly calms you down and takes the edge off anxiety and that busy won't shut up brain.
Hope that helps a bit
Fran
Valium and the other benzodiazapams work on the GABA receptor, so has a very similar efect. For me this is the only drug (valium) I can take without adverse reactions. However it is addictive and due to my AF seizure activity did get addicted at one point 20 years or so back. On the odd occasions when things get too much I will take a 2mg tablet - eg when my Mum died. IT certainly calms you down and takes the edge off anxiety and that busy won't shut up brain.
Hope that helps a bit
Fran
|
Fran
Re: accumulation or depletion as the cause discussion October 25, 2003 09:30PM |
"and while i understand the process of causing afib, how does the actual afib process deplete the free glutamate so that the build-up process begins again?"
I don't know. I have supposed it might have to do with the big P or some other chemical reactions caused by AF. Or then again it may because we have unknowingly built up our ATP, inadvertantly eaten less carbs and reduced hypoglycemic reactions, eaten more than enough antioxidants, or a whopping load of Mg etc etc.
All I know is that in my case avoiding free glutamate and focussing on high nutrient food did the trick. So - much the same as all of you I am trying to understand exactly WHY - except I now I have a base line of knowing how to avoid mine 100%.
Fran
I don't know. I have supposed it might have to do with the big P or some other chemical reactions caused by AF. Or then again it may because we have unknowingly built up our ATP, inadvertantly eaten less carbs and reduced hypoglycemic reactions, eaten more than enough antioxidants, or a whopping load of Mg etc etc.
All I know is that in my case avoiding free glutamate and focussing on high nutrient food did the trick. So - much the same as all of you I am trying to understand exactly WHY - except I now I have a base line of knowing how to avoid mine 100%.
Fran
|
PC
Re: accumulation or depletion as the cause discussion October 26, 2003 05:16AM |
Gregg,
This theory is definitely on the radar. If you visit the Proceedings of the Conference Room, Session 1 was devoted to this very topic. Sessions 4 and 5 specifically address glutamate and its possible role in all this.
Many have made the same observation that your first post contains. Fran's glutamate being the culprit makes a lot of sense.
Your last post about how the AF process depletes the free glutamate to begin the process anew is an excellent one.
We've talked a little about that before. Perhaps the following might explain how this might occur.
Let's assume that there is a slight problem with removing or breaking down glutamate (enzymatic degradation by glutamate decarboxylase). This could be due to either a polymorphism of the gene for glutamate decarboxylase (see previous posts at [www.afibbers.org])
or a shortage of Vitamin B6 or Mg (both required for the reaction).
In the time period after AF the neurotransmitter glutamate in the brainstem is released (to stimulate the vagus nerve fibers some of which go to the heart). Since there is difficulty in removing it, it may slowly buildup in that space (this is called the synaptic cleft). Remember that this release of glutamate is not constant but can not only pulse wrt physical activity (and body position) but also has a diurnal component. At some point the supply of secreted glutamate overwhelms the body's ability to remove it, triggering vagally mediated AF.
During AF blood pressure can vary considerably. I suspect that a drop of about 30% in cardiac output (due to the absence of the atrial kick) translates to a drop in the mean BP. However, the occasional increases in hydrostatic pressure around the carotid baroreceptor could result in a constant barrage of signals to the brain that stimulate the vagus. This could result in gradual depletion of the secreting nerves' stores of glutamate. If AF was strictly vagolytic, then theoretically any vagolytic condition or activity, e.g., exercise, prolonged standing, dehydration, etc., should "clear the deck".
Perhaps during AF there is gradual depletion of glutamate and the body has a chance to wipe the slate clean before accummulation slowly starts again after termination.
I've always been impressed with how high/low my HR and HRV are respectively immediately after an episode. This can last for several hours before slowly reverting to normal and its length is directly proportional to the length of the AF episode. This observation seems to support the baroreceptor approach.
However, there are some minor wrinkles in this interpretation.
It certainly doesn't explain adrenergic AF. And it doesn't explain some other conditions associated with AF, e.g., hyperthyroidism, hypokalemic periodic paralysis, both of which have about 10% association with AF.
Also, I've experimented with Vit B6 and Mg in significant doses in an attempt to thwart AF without success. However, I'm having some success with disopyramide (Norpace) at controlling vagal tone.
I've previously posted on baroreceptors wrt weightlessness and prolonged standing as a trigger for AF.
[www.afibbers.org]
[www.yourhealthbase.com]
Many Vagal LAFers complain of a post exercise vagal rebound. Could it be that during the baroreceptor mediated vagolysis of exercise, prolonged standing, dehydration, etc., there is a buildup of glutamate within the nerve. This enhanced supply of glutamate could then result in enhanced vagal tone subsequently initiated by any vagal maneuver (swallowing, sitting down after ascending a flight of stairs, lying down, etc.).
More likely, this is all just the ramblings of an overactive imagination.
PC v54
This theory is definitely on the radar. If you visit the Proceedings of the Conference Room, Session 1 was devoted to this very topic. Sessions 4 and 5 specifically address glutamate and its possible role in all this.
Many have made the same observation that your first post contains. Fran's glutamate being the culprit makes a lot of sense.
Your last post about how the AF process depletes the free glutamate to begin the process anew is an excellent one.
We've talked a little about that before. Perhaps the following might explain how this might occur.
Let's assume that there is a slight problem with removing or breaking down glutamate (enzymatic degradation by glutamate decarboxylase). This could be due to either a polymorphism of the gene for glutamate decarboxylase (see previous posts at [www.afibbers.org])
or a shortage of Vitamin B6 or Mg (both required for the reaction).
In the time period after AF the neurotransmitter glutamate in the brainstem is released (to stimulate the vagus nerve fibers some of which go to the heart). Since there is difficulty in removing it, it may slowly buildup in that space (this is called the synaptic cleft). Remember that this release of glutamate is not constant but can not only pulse wrt physical activity (and body position) but also has a diurnal component. At some point the supply of secreted glutamate overwhelms the body's ability to remove it, triggering vagally mediated AF.
During AF blood pressure can vary considerably. I suspect that a drop of about 30% in cardiac output (due to the absence of the atrial kick) translates to a drop in the mean BP. However, the occasional increases in hydrostatic pressure around the carotid baroreceptor could result in a constant barrage of signals to the brain that stimulate the vagus. This could result in gradual depletion of the secreting nerves' stores of glutamate. If AF was strictly vagolytic, then theoretically any vagolytic condition or activity, e.g., exercise, prolonged standing, dehydration, etc., should "clear the deck".
Perhaps during AF there is gradual depletion of glutamate and the body has a chance to wipe the slate clean before accummulation slowly starts again after termination.
I've always been impressed with how high/low my HR and HRV are respectively immediately after an episode. This can last for several hours before slowly reverting to normal and its length is directly proportional to the length of the AF episode. This observation seems to support the baroreceptor approach.
However, there are some minor wrinkles in this interpretation.
It certainly doesn't explain adrenergic AF. And it doesn't explain some other conditions associated with AF, e.g., hyperthyroidism, hypokalemic periodic paralysis, both of which have about 10% association with AF.
Also, I've experimented with Vit B6 and Mg in significant doses in an attempt to thwart AF without success. However, I'm having some success with disopyramide (Norpace) at controlling vagal tone.
I've previously posted on baroreceptors wrt weightlessness and prolonged standing as a trigger for AF.
[www.afibbers.org]
[www.yourhealthbase.com]
Many Vagal LAFers complain of a post exercise vagal rebound. Could it be that during the baroreceptor mediated vagolysis of exercise, prolonged standing, dehydration, etc., there is a buildup of glutamate within the nerve. This enhanced supply of glutamate could then result in enhanced vagal tone subsequently initiated by any vagal maneuver (swallowing, sitting down after ascending a flight of stairs, lying down, etc.).
More likely, this is all just the ramblings of an overactive imagination.
PC v54
|
peggy merrill
Re: accumulation or depletion as the cause discussion October 26, 2003 06:11AM |
|
Richard
Re: accumulation or depletion as the cause discussion October 26, 2003 09:45AM |
To All,
PC, that was very interesting, and especially today, since I just went out of rhythm. That is the third time, since May and the beginning of using Flec. again. The first time I went out of rhythm was after eating bean dip from the grocery, with sour cream, and yes Doritoes. The second time I went out of rhythm was because I was away on a trip, and was dining in restaurants. Today, the reason. Jimmy Dean sausage. I knew it had monosodium glutamate, but did it anyway, and wha-la!!, FLUTTER. So Fran, you're absolutely RIGHT. Now my real focus is on why glutamate builds up. I will avoid it like the plague from now on, but I want to know why anyway. Maybe it's the Mo, but that's may not be the case with others here, especially David S. as his Mo hair levels were within range.
As the article below indicates, stress or dehydration can cause ADH secretion and the water that is suppose to eliminate the salts (as in MSG) will be retained. Could we be producing too much ADH, therefore holding in toxins that build up and create havoc. I was a bit stressed today, as we took the boat out of the water, and that's always a bit of a problem. But then again, maybe MSG in itself causes stress to the system.
"antidiuretic hormone , polypeptide hormone secreted by the posterior pituitary gland. Its principal action is to regulate the amount of water excreted by the kidneys. Antidiuretic hormone (ADH), known also as vasopressin, causes the kidneys to resorb water directly from the renal tubules, thus concentrating the salts and waste products in the liquid, which will eventually become urine. ADH secretion by the pituitary is regulated by neural connections from the hypothalamus, which is believed to monitor either the volume of blood passing through it or the concentration of water in the blood. Dehydration or body stress will raise ADH secretion and water will be retained. Alcohol inhibits ADH secretion. Failure of the pituitary to produce ADH results in diabetes insipidus. In pharmacological doses ADH acts as a vasoconstrictor. The structure and chemical synthesis of ADH was announced (1953) by Nobel laureate Vincent Du Vigneaud and others."
[www.factmonster.com]
Another MSG avoider,
Richard
PC, that was very interesting, and especially today, since I just went out of rhythm. That is the third time, since May and the beginning of using Flec. again. The first time I went out of rhythm was after eating bean dip from the grocery, with sour cream, and yes Doritoes. The second time I went out of rhythm was because I was away on a trip, and was dining in restaurants. Today, the reason. Jimmy Dean sausage. I knew it had monosodium glutamate, but did it anyway, and wha-la!!, FLUTTER. So Fran, you're absolutely RIGHT. Now my real focus is on why glutamate builds up. I will avoid it like the plague from now on, but I want to know why anyway. Maybe it's the Mo, but that's may not be the case with others here, especially David S. as his Mo hair levels were within range.
As the article below indicates, stress or dehydration can cause ADH secretion and the water that is suppose to eliminate the salts (as in MSG) will be retained. Could we be producing too much ADH, therefore holding in toxins that build up and create havoc. I was a bit stressed today, as we took the boat out of the water, and that's always a bit of a problem. But then again, maybe MSG in itself causes stress to the system.
"antidiuretic hormone , polypeptide hormone secreted by the posterior pituitary gland. Its principal action is to regulate the amount of water excreted by the kidneys. Antidiuretic hormone (ADH), known also as vasopressin, causes the kidneys to resorb water directly from the renal tubules, thus concentrating the salts and waste products in the liquid, which will eventually become urine. ADH secretion by the pituitary is regulated by neural connections from the hypothalamus, which is believed to monitor either the volume of blood passing through it or the concentration of water in the blood. Dehydration or body stress will raise ADH secretion and water will be retained. Alcohol inhibits ADH secretion. Failure of the pituitary to produce ADH results in diabetes insipidus. In pharmacological doses ADH acts as a vasoconstrictor. The structure and chemical synthesis of ADH was announced (1953) by Nobel laureate Vincent Du Vigneaud and others."
[www.factmonster.com]
Another MSG avoider,
Richard
|
Richard
Re: accumulation or depletion as the cause discussion October 26, 2003 10:24AM |
Also, there could be a possible correlation to elevated ADH and Menieres, which is partly to do with ringing in the ears, even though the study wasn't substantial.
[www.ncbi.nlm.nih.gov]
Richard
[www.ncbi.nlm.nih.gov]
Richard
|
Fran
Re: accumulation or depletion as the cause discussion October 27, 2003 07:19AM |
I used to suffer from vertigo. I was sent to the hosptital to check it out. The Dr I spoke to told me that he thought I had menieres. I didn't think it was this as the menieres I had read about incurred hearing loss etc. My hearing is very very good.
What I did discover was that MSG, apartame, paracetamol, antibiotics, and the drug serc they gave for the menieres brought on attacks. They could last for two weeks. I haven't had an attack for years now.....
Will check up on your link
Thanks
Fran
What I did discover was that MSG, apartame, paracetamol, antibiotics, and the drug serc they gave for the menieres brought on attacks. They could last for two weeks. I haven't had an attack for years now.....
Will check up on your link
Thanks
Fran
|
john
Re: accumulation or depletion as the cause discussion October 28, 2003 12:04AM |
I can't even follow this discussion! What contains free glutamate and how does one avoid it? Anecdotal evidence, my own experience included, indicates some sort of build up of something, so I believe in the theory. But it is absolutely mind boggling to try to figure out exactly what you guys are saying. Can someone explain it in simple terms, please?
|
Fran
Re: accumulation or depletion as the cause discussion October 28, 2003 05:19AM |
[www.msgmyth.com]
Glutamic acid is just one of many amino acids that are the building blocks of proteins. It occurs naturally in many foods such as tomatoes, milk, and mushrooms. It is also found in the cells of our bodies, including mother's milk, and involves a wide variety of brain functions since it functions as a neurotransmitter. This natural glutamate in plants and animals is known as L-glutamic acid.
Our normal digestive process slowly breaks down this natural or "bound" glutamic acid and it is then delivered to glutamate receptors in our body and brain. Broken down this way, it is harmless. In a factory, however, the bound glutamic acid in certain foods (corn, molasses, wheat) is broken down or made "free" by various processes (hydrolyzed, autolyzed, modified or fermented with strong chemicals, bacteria, or enzymes) and refined to a white crystal that resembles sugar. This substance is known as monosodium glutamate or MSG. It is 78.2% glutamate, 12.2% sodium, and 9.6% water. It is odorless and has no distinct flavor, although some describe a salty/sweet flavor. Its chemical formulation has been modified and it is technically known as D-glutamic acid. It also contains some L-glutamic acid, pyroglutamic acid, and other contaminants This factory made version causes sensitive individuals more serious reactions than any other form of glutamic acid. Keep in mind that there is no D-glutamic acid, pyroglutamic acid, or other contaminants in the protein found in plants and animals, only L-glutamic acid.
We are getting far too much MSG in the growing number of processed food items that we have come to rely on. Since free glutamate can be a component part of certain food additives, such as autolyzed yeast or hydrolyzed protein, the FDA allows it to go into food unlabeled as MSG. A label may say "yeast extract", "calcium caseinate", or "beef flavoring", but the product still contains varying amounts of "free" glutamic acid. This makes it very difficult for consumers who are trying to avoid it. It is also very dangerous for those who suffer severe reactions to it.
Monosodium glutamate in the form of a dried seaweed (Kombu) has been used for thousands of years in East Asian countries. Today, free glutamate or MSG is made from many different raw materials (mostly corn) using various chemical processes previously mentioned. Strong acids, alkalies, enzymes, bacteria, and heat are used to hydrolyze animal, vegetable, or milk products. Calcium and sodium caseinate are products of hydrolyzed milk protein. Maltodextrin comes from processed corn and although corn syrup and cornstarch are not as highly processed as maltodextrin is, they may not be totally free of glutamate as a result of their production. Yeast extract or autolyzed yeast is made by chemically processing natural yeast in a method similar to hydrolyzing. Barley malt and malt extract have small amounts of MSG because of an enzyme reaction used to produce them. Whey protein concentrate or protein isolate may contain MSG if hydrolyzed milk proteins are present or added. Soy protein isolate or soy protein concentrate is processed from soy beans and is often a component of textured protein. Most smoke flavor or smoke flavorings use hydrolyzed protein to intensify flavor. Some other "free" glutamate containing products are gelatins, which are highly processed by-products of animal protein that always contain MSG in varying amounts, and soy sauce, made from a fermentation process of soy beans. MSG can also be added to cheaper brands of soy sauce to enhance the flavor. Carrageenan is made from a type of seaweed known as Irish moss. It may contain MSG depending on its manufacturer. MSG or hydrolyzed milk protein is often added to it. The book, Battling the MSG Myth goes on to cover many other hidden sources and the foods in which they are hidden.
What exactly is MSG?
[www.msgtruth.org]
MSG, or Monosodium Glutamate is a salt of the amino acid - Glutamic Acid (glutamate). A salt is the chemical name for a molecule held together by opposite charges. Basically one (mono) sodium atom is "stuck" to the amino acid glutamate.
What is an amino acid?
Amino acids are often called the building blocks of life because it takes many of them linked together in a chain to create a protein. DNA tells the body how to make the chain and in what order the amino acids must line up. Some amino acids must be eaten because the body cannot make them (essential), some the body can make (non-essential), and yet others are able to be made during some times, but not others (conditionally essential). The life processes are all dependent on proteins which play critical roles in the body as structure, messengers, enzymes, and hormones.
Proteins are globular and clumpy because the amino acid chains fold in on themselves. This is how the immune system recognizes proteins. They are large compared to single amino acids, and they are uniquely shaped. The immune system does not recognize tiny MSG as an allergen. However, trouble can begin because the body can attack the larger enzymes like GAD, responsible for turning excess MSG into GABA.
What is an enzyme?
Enzymes are simply proteins with interesting day jobs. Enzymes help make things happen by helping to create other proteins and by helping break them down too. Enzymes are not straight chains, they are globular and clumpy, because they are folded into intricate shapes like other proteins. It is these shapes that help them create and break down other proteins and compounds.
What is a hormone?
Hormones are extremely potent protein based messengers that travel around the body connecting the lines of communication between glands of the endocrine system. These glands direct important functions like metabolism, growth, and sexual development. It has been found lately that smaller amounts of hormones are more effective than larger amounts because the body has feedback mechanisms that don't take kindly to overdoses of hormone. Things shut down because it is considered a trouble signal if there is too much hormone present. By affecting the part of the brain - the hypothalamus, that controls the master gland of the body - the pituitary, MSG may affect hormone production in the body.
Glutamate - Protein Building Block and Excitatory Neurotransmitter....
Glutamate is just one of many amino acids used by the body and linked into the chains of protein in the body. However some amino acids are free to float around by themselves as well as being found linked into proteins because they serve vital functions - some are neurotransmitters which carry nerve cell impulses throughout the body. Amino acid neurotransmitters are like chemical messengers carrying news from nerve cell to nerve cell. Some amino acid neurotransmitters like glutamate trigger nerve cells to fire, others like taurine and gamma amino butyric acid tell those firing nerve cells to cease firing. It is a delicate balance. An important balance. Researchers are finding out just what happens when that balance tips. In patients who suffer a stroke, for example, an excess of glutamate in the brain causes the nerve cells to die from overstimulation. Glutamate blocking drugs are being used to prevent some of this damage.
For more info on neurotransmitters see:
[artsandscience.concordia.ca]
For information on glutamate and excitotoxicity:
[www.memantine.com]
How does the body usually deal with excess amino acids?
Most amino acids if not used right away, are not stored as amino acids. The body has elaborate means of changing extra amino acids into other amino acids, and removing nitrogen and changing amino acids into fuel to be stored. There are processes such as "transamination" and "deamination" which occur mostly in the liver. In patients with compromised livers, however, they may have trouble transaminating cysteine, for example, into taurine, the amino acid that acts counter to glutamate. Also, an excess of the amino acid aspartate (found in Nutrasweet) may result in excess glutamate, since the body can convert aspartate directly to glutamate. Aspartate and glutamate affect some of the same receptors. In a different example, there is an enzyme that the body uses to convert excess glutamate into another neurotransmitter called GABA. In many patients with Type II Diabetes, their bodies view the enzyme responsible for turning MSG into GABA as an enemy and create antibodies to attack it so that it cannot do its job. This is a problem. The body is compromised in its job of getting rid of excess glutamate. It again is a question of balance, and what tips it.
Is manufactured MSG a problem?
According to some MSG opponents the glutamate added to foods is "bad" and the natural glutamate in our bodies is "good". MSG sellers argue that MSG is exactly like the glutamate in the human body, therefore it must always be "good". It is not so simple. There are contaminants in processed MSG. An anology that can be used is that there are right-handed amino acids and left handed ones. They are like mirror images of each other. Processed MSG contains not only the kind of amino acids the body is used to handling, but mirror image ones too. This may cause problems because it is like putting the wrong glove on your hand. It's not quite the same. We don't exactly know what problems this may cause. On the other hand (so to speak) the fact that glutamate the body is used to handling is also in MSG may present a problem because an excess of naturally occurring glutamate is well known by neuroscientists to be a problem in many disease states. Natural glutamate can cause problems we already know about. The reason food processors "free" glutamate from its bound form, is that it acts as a neurotransmitter in its free form. The food industry's claim that free glutamate is as harmless as bound glutamate is disingenous at best. If it was exactly the same, they wouldn't need to hydrolyse vegetable protein (split the amino acids apart).
Why do food companies add MSG to foods?
There are several reasons:
MSG acts as a drug like caffeine. It affects the body by stimulating the nerve cells in your tongue. It is not a "meat tenderizer". It is not a "preservative". It barely has a taste of its own. The food industry is trying to confuse the issue by focusing on the "fifth" taste sense they call umami. However, the truth is, they are using the very same neurotransmitter that your brain uses. It directly affects processes in your body. It changes your perception of taste by altering you.
MSG stimulates the pancreas to produce insulin. The food industry has found their own "anti-appetite suppressant". It's a convenient way to keep consumers coming back for more. The blood sugar drops because of the insulin flood. And you are hungry an hour later. Sound familiar?
The body changes excess glutamate to GABA. GABA may be addictive. It is calming and affects the same receptors in the brain as valium.
Cost. The illusion created by adding MSG to a food product enables the food processor to add LESS real food. The consumer perceives the product - say chicken soup - to have more chicken in it than is actually there. Example: A well-known brand of dehydrated chicken noodle soup. Is that chicken in there, or a piece of confetti?
Foods always contain MSG when these words are on the label:
[www.msgmyth.com]
MSG Gelatin Calcium Caseinate
Monosodium glutamate Hydrolyzed Vegetable Protein Textured Protein
Monopotassium glutamate Hydrolyzed Plant Protein Yeast Extract
Glutamate Autolyzed Plant Protein Yeast food or nutrient
Glutamic Acid Sodium Caseinate Autolyzed Yeast
Foods made with the following products often contain MSG.
Malted Barley (flavor) Flavors, Flavoring Modified food starch
Barley malt Reaction Flavors Rice syrup or brown rice syrup
Malt Extract or Flavoring Natural Chicken, Beef, or Pork, Flavoring "Seasonings" (Most assume this means salt, pepper, or spices and herbs, which sometimes it is.) Lipolyzed butter fat
Maltodextrin Soy Sauce or Extract "Low" or "No Fat" items
Caramel Flavoring (coloring) Soy Protein Corn syrup and corn syrup solids (some companies use another process to make their product, saying it is MSG free)
Stock Soy Protein Isolate or Concentrate Citric Acid (when processed from corn)
Broth Cornstarch Milk Powder
Bouillon Flowing Agents Dry Milk Solids
Carrageenan Wheat, rice, or oat protein Protein Fortified Milk
Whey Protein or Whey Anything enriched or vitamin enriched Annatto
Whey Protein Isolate or Concentrate Protein fortified "anything" Spice
Pectin Enzyme modified "anythng" Gums
Protease Ultra-pasteurized "anything" Dough Conditioners
Protease enzymes Fermented "anything" Yeast Nutrients
Did You Know...
That most doctors, dietitians and the public know very little about the toxic effects of MSG?
That the billion dollar processed food industry and MSG producers pay lobbyists to make all of us believe MSG is safe for the majority of the population?
That monosodium glutamate is the sodium salt of glutamic acid, a nonessential amino acid used to enhance food flavors? But it is also an excitatory neurotransmitter that destroys nerve cells in the brain of susceptible people?
That 30 to 40% or more of our population is experiencing the harmful effects of what the medical society has recently called the "MSG Symptom Complex" and many of us don't know it?
Most of us ingest more MSG than we realize or than the FDA and researchers regard as safe?
That the amount of MSG added to our processed foods has doubled every 10 years?
That MSG is not just used in East Asian restaurants, but in most restaurants and most bagged, bottled, frozen, boxed, canned, or commercially prepared foods?
That additives such as hydrolyzed protein and autolyzed yeast can contain as much as 40% MSG, and do not have to be labeled as such?
That aspartame and L-cysteine are other powerful excitotoxins that cause similar damage to our bodies?
That Attention Deficit Disorder, Chronic Fatigue Syndrome, some weight problems, migraine headaches, sleeping disorders, Irritable Bowel Syndrome, Glaucoma, Asthma, Diabetes, and neurological disorders such as Alzheimer's, ALS (Lou Gehrig's disease), and Parkinson's may have more in common than we think?
That we as a people tend to take at least 20 years to accept what earlier tests warn us is harmful to us, especially when it means giving up something we enjoy? Consider tobacco and caffeine.
That your body is your best source of the truth? According to Funk and Wagnall's Standard Desk Dictionary (volume 1, 1980), a myth is "a false opinion, belief, or ideal." Test yourself by using our suggestions and see if you or your loved ones are suffering needlessly due to the "MSG Myth" and those who promote it.
Many people who have had such toxic reactions because of MSG also have to avoid high sources of natural free glutamate in a bid to normalise levels eg over cooked tomatoes, mushrooms etc.
Hope you followed this. There is tons more in the conference room.
Fran
Glutamic acid is just one of many amino acids that are the building blocks of proteins. It occurs naturally in many foods such as tomatoes, milk, and mushrooms. It is also found in the cells of our bodies, including mother's milk, and involves a wide variety of brain functions since it functions as a neurotransmitter. This natural glutamate in plants and animals is known as L-glutamic acid.
Our normal digestive process slowly breaks down this natural or "bound" glutamic acid and it is then delivered to glutamate receptors in our body and brain. Broken down this way, it is harmless. In a factory, however, the bound glutamic acid in certain foods (corn, molasses, wheat) is broken down or made "free" by various processes (hydrolyzed, autolyzed, modified or fermented with strong chemicals, bacteria, or enzymes) and refined to a white crystal that resembles sugar. This substance is known as monosodium glutamate or MSG. It is 78.2% glutamate, 12.2% sodium, and 9.6% water. It is odorless and has no distinct flavor, although some describe a salty/sweet flavor. Its chemical formulation has been modified and it is technically known as D-glutamic acid. It also contains some L-glutamic acid, pyroglutamic acid, and other contaminants This factory made version causes sensitive individuals more serious reactions than any other form of glutamic acid. Keep in mind that there is no D-glutamic acid, pyroglutamic acid, or other contaminants in the protein found in plants and animals, only L-glutamic acid.
We are getting far too much MSG in the growing number of processed food items that we have come to rely on. Since free glutamate can be a component part of certain food additives, such as autolyzed yeast or hydrolyzed protein, the FDA allows it to go into food unlabeled as MSG. A label may say "yeast extract", "calcium caseinate", or "beef flavoring", but the product still contains varying amounts of "free" glutamic acid. This makes it very difficult for consumers who are trying to avoid it. It is also very dangerous for those who suffer severe reactions to it.
Monosodium glutamate in the form of a dried seaweed (Kombu) has been used for thousands of years in East Asian countries. Today, free glutamate or MSG is made from many different raw materials (mostly corn) using various chemical processes previously mentioned. Strong acids, alkalies, enzymes, bacteria, and heat are used to hydrolyze animal, vegetable, or milk products. Calcium and sodium caseinate are products of hydrolyzed milk protein. Maltodextrin comes from processed corn and although corn syrup and cornstarch are not as highly processed as maltodextrin is, they may not be totally free of glutamate as a result of their production. Yeast extract or autolyzed yeast is made by chemically processing natural yeast in a method similar to hydrolyzing. Barley malt and malt extract have small amounts of MSG because of an enzyme reaction used to produce them. Whey protein concentrate or protein isolate may contain MSG if hydrolyzed milk proteins are present or added. Soy protein isolate or soy protein concentrate is processed from soy beans and is often a component of textured protein. Most smoke flavor or smoke flavorings use hydrolyzed protein to intensify flavor. Some other "free" glutamate containing products are gelatins, which are highly processed by-products of animal protein that always contain MSG in varying amounts, and soy sauce, made from a fermentation process of soy beans. MSG can also be added to cheaper brands of soy sauce to enhance the flavor. Carrageenan is made from a type of seaweed known as Irish moss. It may contain MSG depending on its manufacturer. MSG or hydrolyzed milk protein is often added to it. The book, Battling the MSG Myth goes on to cover many other hidden sources and the foods in which they are hidden.
What exactly is MSG?
[www.msgtruth.org]
MSG, or Monosodium Glutamate is a salt of the amino acid - Glutamic Acid (glutamate). A salt is the chemical name for a molecule held together by opposite charges. Basically one (mono) sodium atom is "stuck" to the amino acid glutamate.
What is an amino acid?
Amino acids are often called the building blocks of life because it takes many of them linked together in a chain to create a protein. DNA tells the body how to make the chain and in what order the amino acids must line up. Some amino acids must be eaten because the body cannot make them (essential), some the body can make (non-essential), and yet others are able to be made during some times, but not others (conditionally essential). The life processes are all dependent on proteins which play critical roles in the body as structure, messengers, enzymes, and hormones.
Proteins are globular and clumpy because the amino acid chains fold in on themselves. This is how the immune system recognizes proteins. They are large compared to single amino acids, and they are uniquely shaped. The immune system does not recognize tiny MSG as an allergen. However, trouble can begin because the body can attack the larger enzymes like GAD, responsible for turning excess MSG into GABA.
What is an enzyme?
Enzymes are simply proteins with interesting day jobs. Enzymes help make things happen by helping to create other proteins and by helping break them down too. Enzymes are not straight chains, they are globular and clumpy, because they are folded into intricate shapes like other proteins. It is these shapes that help them create and break down other proteins and compounds.
What is a hormone?
Hormones are extremely potent protein based messengers that travel around the body connecting the lines of communication between glands of the endocrine system. These glands direct important functions like metabolism, growth, and sexual development. It has been found lately that smaller amounts of hormones are more effective than larger amounts because the body has feedback mechanisms that don't take kindly to overdoses of hormone. Things shut down because it is considered a trouble signal if there is too much hormone present. By affecting the part of the brain - the hypothalamus, that controls the master gland of the body - the pituitary, MSG may affect hormone production in the body.
Glutamate - Protein Building Block and Excitatory Neurotransmitter....
Glutamate is just one of many amino acids used by the body and linked into the chains of protein in the body. However some amino acids are free to float around by themselves as well as being found linked into proteins because they serve vital functions - some are neurotransmitters which carry nerve cell impulses throughout the body. Amino acid neurotransmitters are like chemical messengers carrying news from nerve cell to nerve cell. Some amino acid neurotransmitters like glutamate trigger nerve cells to fire, others like taurine and gamma amino butyric acid tell those firing nerve cells to cease firing. It is a delicate balance. An important balance. Researchers are finding out just what happens when that balance tips. In patients who suffer a stroke, for example, an excess of glutamate in the brain causes the nerve cells to die from overstimulation. Glutamate blocking drugs are being used to prevent some of this damage.
For more info on neurotransmitters see:
[artsandscience.concordia.ca]
For information on glutamate and excitotoxicity:
[www.memantine.com]
How does the body usually deal with excess amino acids?
Most amino acids if not used right away, are not stored as amino acids. The body has elaborate means of changing extra amino acids into other amino acids, and removing nitrogen and changing amino acids into fuel to be stored. There are processes such as "transamination" and "deamination" which occur mostly in the liver. In patients with compromised livers, however, they may have trouble transaminating cysteine, for example, into taurine, the amino acid that acts counter to glutamate. Also, an excess of the amino acid aspartate (found in Nutrasweet) may result in excess glutamate, since the body can convert aspartate directly to glutamate. Aspartate and glutamate affect some of the same receptors. In a different example, there is an enzyme that the body uses to convert excess glutamate into another neurotransmitter called GABA. In many patients with Type II Diabetes, their bodies view the enzyme responsible for turning MSG into GABA as an enemy and create antibodies to attack it so that it cannot do its job. This is a problem. The body is compromised in its job of getting rid of excess glutamate. It again is a question of balance, and what tips it.
Is manufactured MSG a problem?
According to some MSG opponents the glutamate added to foods is "bad" and the natural glutamate in our bodies is "good". MSG sellers argue that MSG is exactly like the glutamate in the human body, therefore it must always be "good". It is not so simple. There are contaminants in processed MSG. An anology that can be used is that there are right-handed amino acids and left handed ones. They are like mirror images of each other. Processed MSG contains not only the kind of amino acids the body is used to handling, but mirror image ones too. This may cause problems because it is like putting the wrong glove on your hand. It's not quite the same. We don't exactly know what problems this may cause. On the other hand (so to speak) the fact that glutamate the body is used to handling is also in MSG may present a problem because an excess of naturally occurring glutamate is well known by neuroscientists to be a problem in many disease states. Natural glutamate can cause problems we already know about. The reason food processors "free" glutamate from its bound form, is that it acts as a neurotransmitter in its free form. The food industry's claim that free glutamate is as harmless as bound glutamate is disingenous at best. If it was exactly the same, they wouldn't need to hydrolyse vegetable protein (split the amino acids apart).
Why do food companies add MSG to foods?
There are several reasons:
MSG acts as a drug like caffeine. It affects the body by stimulating the nerve cells in your tongue. It is not a "meat tenderizer". It is not a "preservative". It barely has a taste of its own. The food industry is trying to confuse the issue by focusing on the "fifth" taste sense they call umami. However, the truth is, they are using the very same neurotransmitter that your brain uses. It directly affects processes in your body. It changes your perception of taste by altering you.
MSG stimulates the pancreas to produce insulin. The food industry has found their own "anti-appetite suppressant". It's a convenient way to keep consumers coming back for more. The blood sugar drops because of the insulin flood. And you are hungry an hour later. Sound familiar?
The body changes excess glutamate to GABA. GABA may be addictive. It is calming and affects the same receptors in the brain as valium.
Cost. The illusion created by adding MSG to a food product enables the food processor to add LESS real food. The consumer perceives the product - say chicken soup - to have more chicken in it than is actually there. Example: A well-known brand of dehydrated chicken noodle soup. Is that chicken in there, or a piece of confetti?
Foods always contain MSG when these words are on the label:
[www.msgmyth.com]
MSG Gelatin Calcium Caseinate
Monosodium glutamate Hydrolyzed Vegetable Protein Textured Protein
Monopotassium glutamate Hydrolyzed Plant Protein Yeast Extract
Glutamate Autolyzed Plant Protein Yeast food or nutrient
Glutamic Acid Sodium Caseinate Autolyzed Yeast
Foods made with the following products often contain MSG.
Malted Barley (flavor) Flavors, Flavoring Modified food starch
Barley malt Reaction Flavors Rice syrup or brown rice syrup
Malt Extract or Flavoring Natural Chicken, Beef, or Pork, Flavoring "Seasonings" (Most assume this means salt, pepper, or spices and herbs, which sometimes it is.) Lipolyzed butter fat
Maltodextrin Soy Sauce or Extract "Low" or "No Fat" items
Caramel Flavoring (coloring) Soy Protein Corn syrup and corn syrup solids (some companies use another process to make their product, saying it is MSG free)
Stock Soy Protein Isolate or Concentrate Citric Acid (when processed from corn)
Broth Cornstarch Milk Powder
Bouillon Flowing Agents Dry Milk Solids
Carrageenan Wheat, rice, or oat protein Protein Fortified Milk
Whey Protein or Whey Anything enriched or vitamin enriched Annatto
Whey Protein Isolate or Concentrate Protein fortified "anything" Spice
Pectin Enzyme modified "anythng" Gums
Protease Ultra-pasteurized "anything" Dough Conditioners
Protease enzymes Fermented "anything" Yeast Nutrients
Did You Know...
That most doctors, dietitians and the public know very little about the toxic effects of MSG?
That the billion dollar processed food industry and MSG producers pay lobbyists to make all of us believe MSG is safe for the majority of the population?
That monosodium glutamate is the sodium salt of glutamic acid, a nonessential amino acid used to enhance food flavors? But it is also an excitatory neurotransmitter that destroys nerve cells in the brain of susceptible people?
That 30 to 40% or more of our population is experiencing the harmful effects of what the medical society has recently called the "MSG Symptom Complex" and many of us don't know it?
Most of us ingest more MSG than we realize or than the FDA and researchers regard as safe?
That the amount of MSG added to our processed foods has doubled every 10 years?
That MSG is not just used in East Asian restaurants, but in most restaurants and most bagged, bottled, frozen, boxed, canned, or commercially prepared foods?
That additives such as hydrolyzed protein and autolyzed yeast can contain as much as 40% MSG, and do not have to be labeled as such?
That aspartame and L-cysteine are other powerful excitotoxins that cause similar damage to our bodies?
That Attention Deficit Disorder, Chronic Fatigue Syndrome, some weight problems, migraine headaches, sleeping disorders, Irritable Bowel Syndrome, Glaucoma, Asthma, Diabetes, and neurological disorders such as Alzheimer's, ALS (Lou Gehrig's disease), and Parkinson's may have more in common than we think?
That we as a people tend to take at least 20 years to accept what earlier tests warn us is harmful to us, especially when it means giving up something we enjoy? Consider tobacco and caffeine.
That your body is your best source of the truth? According to Funk and Wagnall's Standard Desk Dictionary (volume 1, 1980), a myth is "a false opinion, belief, or ideal." Test yourself by using our suggestions and see if you or your loved ones are suffering needlessly due to the "MSG Myth" and those who promote it.
Many people who have had such toxic reactions because of MSG also have to avoid high sources of natural free glutamate in a bid to normalise levels eg over cooked tomatoes, mushrooms etc.
Hope you followed this. There is tons more in the conference room.
Fran
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