{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,16]],"date-time":"2026-01-16T04:00:07Z","timestamp":1768536007530,"version":"3.49.0"},"reference-count":0,"publisher":"American Physiological Society","issue":"4","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["American Journal of Physiology-Gastrointestinal and Liver Physiology"],"published-print":{"date-parts":[[1991,10,1]]},"abstract":"<jats:p> The objective of this study was to determine whether L-glutamate (L-Glu) may serve as a neurotransmitter candidate in the guinea pig myenteric plexus. We observed that [3H]Glu and gamma-[3H]aminobutyric acid were synthesized from [3H]glutamine and released from neurons of the myenteric plexus during K+ and 1,1-dimethyl-4-phenylpiperazinium-evoked depolarization in a concentration-dependent manner. Muscle tension studies performed on ileal longitudinal muscle-myenteric plexus (LM-MP) preparations revealed that L-Glu [mean effective dose (ED50) 2.5 x 10(-5) M] produced concentration-dependent contractions, which were unaffected by hexamethonium but abolished by tetrodotoxin, atropine, and magnesium, suggesting that L-Glu acts via N-methyl-D-aspartate (NMDA)-type receptors that stimulate a cholinergic neural pathway unaffected by ganglionic blockade. In addition, L-Glu (ED50 4 x 10(-5) M) and NMDA (ED50 2 x 10(-4) M) stimulated concentration-dependent release of [3H]acetylcholine (ACh) from LM-MP sections, which was inhibited by tetrodotoxin, magnesium, and the NMDA receptor antagonist D-2-amino-5-phosphonovaleric acid (AP-5). L-Glu-mediated release of [3H]ACh was enhanced by theophylline (10-6 M) and 3-isobutyl-1-methylxanthine (1 mM) and was significantly reduced by the adenylate cyclase inhibitor, 2',5'-dideoxyadenosine (10(-4) M) and somatostatin-14 (10(-6) M), which inhibits adenosine 3',5'-cyclic monophosphate (cAMP)-dependent cholinergic transmission in the myenteric plexus. These studies suggest that L-Glu may serve as an excitatory neurotransmitter in the myenteric plexus via its action on NMDA-type receptors, which are coupled to cAMP-dependent release of ACh. <\/jats:p>","DOI":"10.1152\/ajpgi.1991.261.4.g693","type":"journal-article","created":{"date-parts":[[2017,12,24]],"date-time":"2017-12-24T00:57:58Z","timestamp":1514077078000},"page":"G693-G700","source":"Crossref","is-referenced-by-count":7,"title":["Evidence for a glutamatergic neural pathway in the myenteric plexus"],"prefix":"10.1152","volume":"261","author":[{"given":"J. W.","family":"Wiley","sequence":"first","affiliation":[{"name":"Department of Internal Medicine, University of Michigan MedicalCenter, Ann Arbor 48109."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Y. X.","family":"Lu","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, University of Michigan MedicalCenter, Ann Arbor 48109."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"C.","family":"Owyang","sequence":"additional","affiliation":[{"name":"Department of Internal Medicine, University of Michigan MedicalCenter, Ann Arbor 48109."}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"24","container-title":["American Journal of Physiology-Gastrointestinal and Liver Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.physiology.org\/doi\/pdf\/10.1152\/ajpgi.1991.261.4.G693","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2019,9,8]],"date-time":"2019-09-08T22:30:09Z","timestamp":1567981809000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.physiology.org\/doi\/10.1152\/ajpgi.1991.261.4.G693"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1991,10,1]]},"references-count":0,"journal-issue":{"issue":"4","published-print":{"date-parts":[[1991,10,1]]}},"alternative-id":["10.1152\/ajpgi.1991.261.4.G693"],"URL":"https:\/\/doi.org\/10.1152\/ajpgi.1991.261.4.g693","relation":{},"ISSN":["0193-1857","1522-1547"],"issn-type":[{"value":"0193-1857","type":"print"},{"value":"1522-1547","type":"electronic"}],"subject":[],"published":{"date-parts":[[1991,10,1]]}}}