Glutamate agonists may be neurotoxic via both NMDA and non-NMDA receptors
if given i.c.v. The evidence that glutamate is neurotoxic following oral
administration in man (including neonates) is lacking. This has been
convinvingly demonstrated only in neonatal rodents. The August 1995 FASEB
(FDA) report on all aspects of the safety of MSG concluded that orally
administered glutamate was wholly safe, although there may be a very small
subgroup of individuals who show some sensitivity and exhibit peripheral
(not CNS effects). Furher research has been indicated in a small number of
asthmatics who may show sensitivity. Glutamate basically does not enter
the brain, or rather, there is no net accumulation. Compounds like domoic
acid from contaminated mussels, do cross the bbb to activate kainate/AMPA
receptors and produce neurotoxic sequelae.
Peter Roberts
Sandra L Wegert (sandraw at U.Arizona.EDU) wrote:
: Right, agonists at this receptor can be neurotoxic. Glutamate (ie, MSG)
: is suspected to be toxic to the brain because it overexcites these
: receptors. As an aside, I personally doubt that (much) MSG crosses the
: blood-brain barrier in healthy adult humans (it does in babies,
: however) when given in the concentrations found in food. Please, correct
: me on this, I'm playing devil's advocate a little here.
: On 20 Oct 1995, Jason Kennerly wrote:
: > LSCCLAB <lscclab at biovx1.biology.ucla.edu> writes:
: > > What is NMDA receptor?
: >
: > A receptor stimulated by NMDA.
: > PCP and Ketamine block (antagonize) NMDA's effects at this receptor
: > NMDA's neurotoxicity stems from its excitotoxic effect at this receptor
: > (this isnt the best way to explaine it is it?)
: >
: >
: > --
: > ____ ______ ________ _____
: > / \ | \| /\ | \ jkenner at cello.gina.calstate.edu: > / \| _ \ \/ | _ \
: > /___/\ \___|> > |__|> > BORN TO BE WIRED...
: > / | / /\ | / All the sugar and twice the
: > \_________|______/|___\/__|______/ caffeine of regular netusers!
: > finger me and make a pgp key come.
: >
: >
: ----------------------
:sandraw at U.Arizona.EDU
