Results
Title

Microinjection of L-glutamate into the nucleus ambiguus partially inhibits gastric motility through the NMDA receptor - nitric oxide pathway.

Authors

Hong-Zhao Sun; Shu-Zhen Zhao; Hong-Bin Ai

Abstract

We have previously reported that both L-glutamate (L-Glu) and nitric oxide (NO) modulate gastric motility in the nucleus ambiguus (NA). The aim of this study is to explore the potential correlation between the L-Glu and NO. A latex balloon connected to a pressure transducer was inserted into the pylorus through the fundus of anesthetized male Wistar rats to continuously record changes in gastric smooth muscle contractile curves. Pretreatment with the NO-synthase inhibitor N-nitro- L-arginine methylester (L-NAME) did not completely abolish the inhibitory effect of L-Glu on gastric motility, but intravenous injection of the ganglionic blocker hexamethonium bromide (Hb) did. By using a specific N-methyl-D-aspartic acid (NMDA) receptor antagonist, we blocked the inhibitory effect of the NO-donor sodium nitroprusside (SNP) on gastric motility. These results suggest that microinjections of L-Glu into the NA inhibits gastric motility by activating the cholinergic preganglionic neurons, partially through the NMDA receptor - NO pathway.

Subjects

METHYL aspartate receptors; GASTROINTESTINAL motility; GLUTAMIC acid; NITRIC oxide; MICROINJECTIONS; LABORATORY animals; SODIUM nitroferricyanide

Publication

Canadian Journal of Physiology & Pharmacology, 2014, Vol 92, Issue 6, p455

ISSN

0008-4212

Publication type

Academic Journal

DOI

10.1139/cjpp-2013-0413