Calcium-dependent release of endogenous glutamate from vascularly perfused rat stomach in vitro

✍ Scribed by Y. Okuma; K. Yokotani; K. Nakamura; Y. Osumi

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 453 KB
• Volume: 44
• Category: Article
• ISSN: 0360-4012
• DOI: 10.1002/(sici)1097-4547(19960601)44:5<507::aid-jnr11>3.0.co;2-y

✦ Synopsis

of Endogenous Perfused Rat

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 KCIinduced release of glutamate was abolished in calciumfree medium containing ethylene glycol bis (p-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.