Fwd: research on glutamate receptors

[Guest guest]

More thoughts on glutamate that I wrote a long time ago:

>I get concerned that there is a bit of a lack in balance in some of the

>talk about excitotoxins, especially glutamate.

>

>As a reminder the 10 amino acids that we can produce from other things are

>alanine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine,

>glycine, proline, serine and tyrosine.

>(Notice how many of those are excitatory!) Controlling there amount in

>the diet doesn't particularly effect how much of these will end up

>anywhere in the body since their manufacture is controlled and regulated.

>

>I try to watch the movement and conversion of molecules in the same way

>that an economist watches the money supply... If you look at the amino

>acid composition of animal protein (including our muscle) the main amino

>acids are the " excitotoxins " . That means that in the usual constant

>recycling of cellular proteins (where most of our amino acids that we use

>derive) all our cells get a huge dose of so-called excitotoxins. If this

>were a problem, why would we be designed this way?

>

>If you look at the numbers involved, some of the attempts to control

>glutamate would have to be like controlling one drop in a bucket! I

>have certainly heard of the people who react fiercely to MSG, but I don't

>think that is from its glutamate content as much as from some diifference

>in how those people are handling this particular compound.... We don't

>worry about glutamate being in glutathione! One of glutathione's chief

>jobs in the kidney is related to losing its glutamate with the help of GGT

>and then attaching its glutamate to other amino acids to help their

>absorption!

>

>About a third of my graduate school classes were in neuroscience, and I

>was really struck then about how old the models were in that field

>compared to what I was learning in the biology department about the

>advances in understanding cell signalling that effects all cells pretty

>much equally. It is hard to find the literature on this unless you know

>to look for it because the strength of old models makes finding the new

>information like looking for a needle in a haystack. The interactions

>with glutamate are everywhere, not just in the synapses between

>neurons. Have you ever looked up where you find NMDA receptors, for

>instance? I've put articles below showing NMDA receptors in endothelial,

>epithelial, muscle, lymphocyte, and beta-cells. I could go on for other

>cell types...but these aren't neurons!

>

>What is unique about the brain is that it is literally bathed in

>glutamine. I'm attaching a chart showing the relative composition of

>amino acids in blood, urine and csf. Watch glutamine and watch glutamate

>levels in these three compartments and their ratio. If the brain is

>bathed in glutamine, the idea to restrict the number one nutrient of the

>gut (glutamine) in an attempt to prevent its turning into glutamate when

>glutamate is a critical component of glutathione and is made by the body

>out of other amino acids anyway makes absolutely no sense to me, and I've

>heard many parents worrying about giving glutamine for this very reason

>and in worry about ammonia. Why would the brain be bathed in glutamine if

>this were a toxic setup for excess ammonia?

>

>So much about cell signalling is an issue of the relative ratios of

>chemicals intracellularly versus in the immediate extracellular

>environment. I think a lot of receptors have the job of telling the cell

>how much of something is outside the cell so the cell can make adjustments

>in its own chemistry. It is not all about firing neurons!

>

>Sorry to get on a tear, but I realize there are a lot of facts some people

>may have never heard!

>

>I don't know about glutamate decarboxylase, as no one has looked, but some

>decarboxylases are inhibited by oxalate. Many bacterial decarboxylases

>are inhibited by oxalate and we know that because someone suspected it and

>looked for it, but we don't know much about our cells and decarboxylases

>and that sort of inhibition.

>

>I hope you find some of this interesting!

>

>

>

>

>Vopr Med Khim. 1996 Oct-Dec;42(4):306-8.Links

>

>

>

>

>[Enzyme activity and level of GABA-shunt substrates in rat brain during

>repeated exposure to hypoglycemic doses of insulin]

>

>

>

>[Article in Russian]

>

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Telushki\

n%20PK%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pub\

med_RVAbstractPlus>Telushkin

>PK,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Shidlovs\

kaia%20TE%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.\

Pubmed_RVAbstractPlus>Shidlovskaia

>TE.

>

>The activity of glutamate decarboxylase, GABA-, aspartate-and alanine

>aminotransferases, the content of GABA, glutamate, aspartate and alanine

>were studied in the brain hemispheres and stem of rats that were

>undergoing the hypoglycemic coma as well as those rats had undergone 7-9

>comas on the second day after the last coma. In hypoglycemia, the brain's

>content of glutamate, alanine and GABA decreased and content of aspartate

>increased; the activity of enzymes investigated did not change. On the

>second day after 7-9th hypoglycemic coma, the decrease of activity of

>glutamate decarboxylase in hemispheres and the decrease of GABA amount in

>brain stem were detected. This can be an evidence of decrease of GABA

>amount produced and secreted by nerve ends of the pathways leading from

>striata to substantia nigra. The detected changes result from multiple

>influence of hypoglycemia to the brain and may by important in the

>development of posthypoglycemic encephalopathy.

>

>PMID: 9254515 [PubMed - indexed for MEDLINE]

>

>J Physiol. 2006 Sep 15;575(Pt 3):707-20. Epub 2006 Jun

>29.<http://www.ncbi.nlm.nih.gov/entrez/utils/fref.fcgi?PrId=3051 & itool=Abstract\

Plus-def & uid=16809361 & db=pubmed & url=http://www.jphysiol.org/cgi/pmidlookup?view=\

long & pmid=16809361>

>Click here to read

>

><http://www.ncbi.nlm.nih.gov/entrez/utils/fref.fcgi?PrId=3494 & itool=AbstractPlu\

s-nondef & uid=16809361 & db=pubmed & url=http://www.pubmedcentral.nih.gov/articlerend\

er.fcgi?tool=pubmed & pubmedid=16809361>

>Click here to read

> Links

>

>

>

>

>Glutamate acts at NMDA receptors on fresh bovine and on cultured human

>retinal pigment epithelial cells to trigger release of ATP.

>

>

>

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Reigada%\

20D%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed\

_RVAbstractPlus>Reigada

>D,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Lu%20W%2\

2%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVAb\

stractPlus>Lu

>W,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22\

%20CH%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubm\

ed_RVAbstractPlus>

>CH.

>

>Department of Physiology, University of Pennsylvania, 3700 Hamilton Walk,

>Philadelphia, PA 19104-6085, USA.

>

>The photoreceptors lie between the inner retina and the retinal pigment

>epithelium (RPE). The release of glutamate by the phototoreceptors can

>signal changes in light levels to inner retinal neurons, but the role of

>glutamate in communicating with the RPE is unknown. Since RPE cells are

>known to release ATP, we asked whether glutamate could trigger ATP release

>from RPE cells and whether this altered cell signalling. Stimulation of

>the apical face of fresh bovine RPE eyecups with 100 mum NMDA increased

>ATP levels more than threefold, indicating that both receptors for NMDA

>and release of ATP occurred across the apical membrane of fresh RPE cells.

>NMDA increased ATP levels bathing cultured human ARPE-19 cells more than

>twofold, with NMDA receptor inhibitors MK-801 and d-AP5 preventing this

>release. Blocking the glycine site of the NMDA receptor with

>5,7-dichlorokynurenic acid prevented ATP release from ARPE-19 cells.

>Release was also blocked by channel blocker NPPB and Ca(2+) chelator

>BAPTA, but not by cystic fibrosis transmembrane conductance regulator

>(CFTR) blocker glibenclamide or vesicular release inhibitor brefeldin A.

>Glutamate produced a dose-dependent release of ATP from ARPE-19 cells that

>was substantially inhibited by MK-801. NMDA triggered a rise in cell

>Ca(2+) that was blocked by MK-801, by the ATPase apyrase, by the P2Y(1)

>receptor antagonist MRS2179 and by depletion of intracellular Ca(2+)

>stores with thapsigargin. These results suggest that glutamate stimulates

>NMDA receptors on the apical membrane of RPE cells to release ATP. This

>secondary release can amplify the glutaminergic signal by increasing

>Ca(2+) inside RPE cells, and might activate Ca(2+)-dependent conductances.

>The interplay between glutaminergic and purinergic systems may thus be

>important for light-dependent interactions between photoreceptors and the RPE.

>

>PMID: 16809361 [PubMed - indexed for MEDLINE]

>

>Vasc Med. 2005

>Aug;10(3):215-23.<http://www.ncbi.nlm.nih.gov/entrez/utils/fref.fcgi?PrId=3051 & \

itool=AbstractPlus-def & uid=16235775 & db=pubmed & url=http://vmj.sagepub.com/cgi/pmi\

dlookup?view=long & pmid=16235775>

>Click here to read

> Links

>

>

>

>

>Homocysteine-induced vascular dysregulation is mediated by the NMDA receptor.

>

>

>

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Qureshi%\

20I%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed\

_RVAbstractPlus>Qureshi

>I,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Chen%20H\

%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RV\

AbstractPlus>Chen

>H,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Brown%20\

AT%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_\

RVAbstractPlus>Brown

>AT,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Fitzgera\

ld%20R%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pub\

med_RVAbstractPlus>Fitzgerald

>R,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Zhang%20\

X%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_R\

VAbstractPlus>Zhang

>X,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Breckenr\

idge%20J%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.P\

ubmed_RVAbstractPlus>Breckenridge

>J,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Kazi%20R\

%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RV\

AbstractPlus>Kazi

>R,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Crocker%\

20AJ%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubme\

d_RVAbstractPlus>Crocker

>AJ,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22St%C3%BC\

hlinger%20MC%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPan\

el.Pubmed_RVAbstractPlus>Stühlinger

>MC,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Lin%20K%\

22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVA\

bstractPlus>Lin

>K,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Cooke%20\

JP%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_\

RVAbstractPlus>Cooke

>JP,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Eidt%20J\

F%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_R\

VAbstractPlus>Eidt

>JF,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Moursi%2\

0MM%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed\

_RVAbstractPlus>Moursi

>MM.

>

>Department of Surgery, Division of Vascular Surgery, Central Arkansas

>Veterans Healthcare System, Little Rock, AR 72205, USA.

>

>Elevated plasma homocysteine accelerates myointimal hyperplasia and

>luminal narrowing after carotid endarterectomy. N-methyl D aspartate

>receptors (NMDAr) in rat cerebrovascular cells are involved in

>homocysteine uptake and receptor-mediated stimulation. In the vasculature,

>NMDAr subunits (NR1, 2A-2D) have been identified by sequence homology in

>rat aortic endothelial cells. Exposure of these cells to homocysteine

>increased expression of receptor subunits, an effect that was attenuated

>by dizocilpine (MK801), a noncompetitive NMDA inhibitor. The objective of

>this study was to investigate the existence of an NMDAr in rat vascular

>smooth muscle (A7r5) cells, and also the effect of homocysteine on

>vascular dysregulation as mediated by this receptor. Subunits of the NMDAr

>(NR1, 2A-2D) were detected in the A7r5 cells by using the reverse

>transcriptase polymerase chain reaction and Western blotting. Homocysteine

>induced an increase in A7r5 cell proliferation, which was blocked by

>MK801. Homocysteine, in a dose and time dependent manner, increased

>expression of matrix metallinoproteinase-9 and interleukin-1beta, which

>have been implicated in vascular smooth muscle cell migration and/or

>proliferation. Homocysteine reduced the vascular elaboration of nitric

>oxide and increased the elaboration of the nitric oxide synthase

>inhibitor, asymmetric dimethylarginine. All of these homocysteine mediated

>effects were inhibited by MK801. NMDAr exist in vascular smooth muscle

>cells and appear to mediate, at least in part, homocysteine-induced

>dysregulation of vascular smooth muscle cell functions.

>

>PMID: 16235775 [PubMed - indexed for MEDLINE]

>

>Physiol Res. 1995;44(3):205-8.Links

>

>

>

>

>Muscle NMDA receptors regulate the resting membrane potential through

>NO-synthase.

>

>

>

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Urazaev%\

20AK%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubme\

d_RVAbstractPlus>Urazaev

>AK,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Magsumov\

%20ST%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubm\

ed_RVAbstractPlus>Magsumov

>ST,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Poletaye\

v%20GI%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pub\

med_RVAbstractPlus>Poletayev

>GI,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Nikolsky\

%20EE%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubm\

ed_RVAbstractPlus>Nikolsky

>EE,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Vyskocil\

%20F%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubme\

d_RVAbstractPlus>Vyskocil

>F.

>

>Kazan Medical University, Russia.

>

>The early postdenervation depolarization of rat diaphragm muscle fibres

>(8-10 mV) is substantially smaller (3 mV) when muscle strips are bathed

>with 1 mM L-glutamate (GLU) or N-methyl-D-aspartate (NMDA). The effects of

>GLU and NMDA are not seen in the presence of aminophosphonovaleric acid

>(APV), a blocker of NMDA-subtype of glutamate receptors, 5 mM Mg2+ (which

>blocks NMDA-controlled ion channels) and L-nitroarginine methylester

>(NAME), an inhibitor of NO-synthase. This indicates that NMDA-subtype of

>GLU receptors might be involved in the regulation of the membrane

>potential in muscle fibres, most probably through the NO-synthase system.

>

>PMID: 8869279 [PubMed - indexed for MEDLINE]

>

>Neurochem Int. 2007 Nov-Dec;51(6-7):356-60. Epub 2007 May

>4.<http://www.ncbi.nlm.nih.gov/entrez/utils/fref.fcgi?PrId=3048 & itool=AbstractP\

lus-def & uid=17543418 & db=pubmed & url=http://linkinghub.elsevier.com/retrieve/pii/S\

0197-0186%2807%2900090-3>

>7a27f9ea.jpg

> Links

>

>

>

>

>The excitotoxic effect of NMDA on human lymphocyte immune function.

>

>

>

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Mashkina\

%20AP%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubm\

ed_RVAbstractPlus>Mashkina

>AP,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Tyulina%\

20OV%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubme\

d_RVAbstractPlus>Tyulina

>OV,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Solovyov\

a%20TI%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pub\

med_RVAbstractPlus>Solovyova

>TI,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Kovalenk\

o%20EI%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pub\

med_RVAbstractPlus>Kovalenko

>EI,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Kanevski\

%20LM%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubm\

ed_RVAbstractPlus>Kanevski

>LM,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22%\

20P%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed\

_RVAbstractPlus>

>P,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Boldyrev\

%20AA%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubm\

ed_RVAbstractPlus>Boldyrev

>AA.

>

>Department of Biochemistry, Moscow State University, 119992 Moscow, Russia.

>

>N-Methyl-d-aspartate (NMDA)-activated glutamate receptors are expressed in

>lymphocytes, but their roles have not yet been defined. We show that

>incubation of human peripheral blood lymphocytes with NMDA resulted in

>increased intracellular calcium and reactive oxygen species (ROS) levels

>through effects on NMDA-activated glutamate receptors. In terms of ROS

>production, T cells were most affected, followed by NK cells, whereas B

>cell ROS levels were not increased. In unstimulated T and NK cells,

>interferon-gamma (IFN-gamma) production was unaffected by NMDA, whereas

>interleukin-2 stimulation of IFN-gamma production was significantly

>suppressed by NMDA. Simultaneous incubation of the cells with NMDA and

>IL-2 resulted in a dramatic increase in the amount of cells expressing the

>NR1 subunit of the NMDA-activated receptors. We conclude that

>NMDA-activated glutamate receptor activation, accompanied by the changes

>in intracellular calcium and ROS levels, may be involved in the

>modification of immune functions of human T and NK cells.

>

>PMID: 17543418 [PubMed - indexed for MEDLINE]

>

>FEBS Lett. 1995 Sep

>11;371(3):253-7.<http://www.ncbi.nlm.nih.gov/entrez/utils/fref.fcgi?PrId=3048 & i\

tool=AbstractPlus-def & uid=7556603 & db=pubmed & url=http://linkinghub.elsevier.com/r\

etrieve/pii/0014-5793%2895%2900890-L>

>7a27fa77.jpg

> Links

>

>

>

>

>Identification of functional ionotropic glutamate receptor proteins in

>pancreatic beta-cells and in islets of Langerhans.

>

>

>

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Moln%C3%\

A1r%20E%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pu\

bmed_RVAbstractPlus>Molnár

>E,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22V%C3%A1r\

adi%20A%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pu\

bmed_RVAbstractPlus>Váradi

>A,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22McIlhinn\

ey%20RA%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pu\

bmed_RVAbstractPlus>McIlhinney

>RA,

><http://www.ncbi.nlm.nih.gov/sites/entrez?Db=pubmed & Cmd=Search & Term=%22Ashcroft\

%20SJ%22%5BAuthor%5D & itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubm\

ed_RVAbstractPlus>Ashcroft

>SJ.

>

>Medical Research Council, Anatomical Neuropharmacology Unit, Oxford, UK.

>

>The presence of ionotropic glutamate receptor proteins in islets of

>Langerhans and pancreatic beta-cell lines (MIN6, HIT T15, RINm5F) was

>investigated. For this purpose immunoblot analysis of beta-cell membranes

>was performed with subunit-specific antibodies. We identified NMDAR1

>subunits of the NMDA and KA-2 subunits of the kainate receptors, but did

>not detect GluR1 subunits of the AMPA receptor. The receptor subunits

>present were shown to be glycosylated. beta-cell membranes contained

>specific binding sites for glutamate receptor ligands, and NMDA increased

>insulin secretion. These results demonstrate that ionotropic glutamate

>receptor proteins, similar to those in the central nervous system, are

>expressed in rat pancreatic beta-cells.

>

>PMID: 7556603 [PubMed - indexed for MEDLINE]

>

>

>

--

No virus found in this outgoing message.

Checked by AVG Free Edition.

Version: 7.5.516 / Virus Database: 269.20.5 - Release Date: 2/14/2008 12:00 AM

[Guest guest]

Thanks for the info re Glutamate, L-Glutamine, and so on.

Going by a health consultant whose opinion on some things I respect, my

own thoughts were that it was a necessary part of normal body functions

(without understanding the chemical interactions and conversions). Not

to say I understand the biological chemistry of it, but you have given

us all the info we need to learn.

thanks!

sol

[Guest guest]

I agree that it glutamine/glutamate is necessary. You can't escape it

as it is found in all types of food, from animal protein to plant

material. Your body obviously uses it for a tremendous number of

functions, from gut function to neurotransmission.

However, based on health status and individual genetic differences,

people may tolerate different amounts and forms. For instance, we

supplemented free form glutamine for my daughter's gut health when she

was a toddler (18 mos. old). She began horrible, horrible headbanging

that stopped when we withdrew the glutamine and began again when we

added it back. I've read other people's posts who NEEDED glutamine

supplementation to be able to focus and sleep. Believe me, I wish we

could tolerate little bit of cheddar cheese or a dash of soy sauce. My

life would be so much easier!

I think the same principle applies to sulfur. Sulfur is found in some

unusual places, composing parts of vitamins and other very necessary

biological compounds. I have one daughter who takes large amounts of

biotin (contains sulfur), but can't tolerate epsom salts or msm. My

other daughter and I can't take that much biotin.

I could elaborate on several other compounds (such as methyl groups,

various vitamins, and minerals) for which there are differing tolerance

levels.

So, all that to say that we should be able to understand certain

compounds are necessary for human life, but form and amount

requirements can be individual. As we have learned here on this board,

we are all individuals, with unique genetic make-ups and environmental

assaults on our systems, which would necessarily influence how our

bodies react to the world around us and the substances we put in our

bodies. There are many chemical processes of the human body that are

not understood, and I'm sure many that haven't been discovered. Then,

consider that they all interact, and it is overwhelming!

It has taken me a long time and money to come to the conclusion that no

one doctor, dietician, or scientist holds all the answers to healing my

family, but I sure can learn a lot from various philosophies and

ideas. Even with all the research and reading I've done, I can't

figure it all out. I have to respect the literature and apply it, but

always keeping in mind the manifestations (good or bad) of trying

various therapies. If we simply say the study says " x-y-z " without

considering the human experience, we are guilty of doing the same thing

we accuse doctors of doing to us thyroid/adrenal patients!

Okay, so that's my soapbox for the day. I hope I didn't step on too

many toes.

>

> Thanks for the info re Glutamate, L-Glutamine, and so on.

> Going by a health consultant whose opinion on some things I respect,

my

> own thoughts were that it was a necessary part of normal body

functions

> (without understanding the chemical interactions and conversions).

Not

> to say I understand the biological chemistry of it, but you have

given

> us all the info we need to learn.

> thanks!

> sol

>