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Calcium‐dependent release of endogenous glutamate from vascularly perfused rat stomach in vitro
Author(s) -
Okuma Y.,
Yokotani K.,
Nakamura K.,
Osumi Y.
Publication year - 1996
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/(sici)1097-4547(19960601)44:5<507::aid-jnr11>3.0.co;2-y
Subject(s) - endogeny , in vitro , glutamate receptor , calcium , chemistry , stomach , biochemistry , pharmacology , biology , receptor , organic chemistry
To investigate a possible physiological role for glutamate in the stomach, release of endogenous glutamate from an isolated vascularly‐perfused rat stomach preparation was studied. Glutamate was measured by the bioluminescence assay method. High concentrations of KCl (30–75 mM) induced a dose‐dependent release of glutamate. This KCl‐induced release of glutamate was abolished in calcium‐free medium containing ethylene glycol bis (β‐aminoethyl ether)‐N,N,N′,N′‐tetraacetic acid (EGTA). Electrical stimulation of the vagus nerves also induced a release of glutamate. This vagal stimulation‐induced release of glutamate was abolished by both calcium removal and tetrodotoxin (TTX). Amounts of 13 other amino acids in the medium, detectable by the automatic amino‐acid analyzer, were not significantly affected by both high‐K + and the vagal stimulation. These results provide additional evidence that glutamate probably serves as a neurotransmitter in the stomach. © 1996 Wiley‐Liss, Inc.