Nitric oxide: Mediator of nonadrenergic noncholinergic responses of opossum esophageal muscle

J. Murray, C. Du, A. Ledlow, J. N. Bates, J. L. Conklin

Research output: Contribution to journalArticle

178 Scopus citations

Abstract

Nonadrenergic noncholinergic (NANC) nerves of the opossum esophagus mediate relaxation of circular muscle from the lower esophageal sphincter (LES) and the off contraction of circular esophageal muscle. The latencies between the end of the stimulus and the off contraction describe a gradient so that the latency is longest in muscle from the caudad esophagus. N(G)-nitro-L-arginine (L-NNA), an inhibitor of nitric oxide (NO) synthase, and NO were used to test the hypothesis whether NO is a mediator of these nerve-induced responses. Both electrical field stimulation (EFS) of intrinsic esophageal nerves and exogenous NO relaxed LES muscle. Only EFS-induced relaxation was inhibited by L-NNA [half-maximal response (EC50) = 60.0 ± 20.0 μM]. L-Arginine, the substrate for NO synthase, reversed the inhibitory effect of L-NNA. Exogenous NO did not contract circular esophageal muscle. Both the amplitude (EC50 = 14.7 ± 4.0 μM) and the latency of the off contraction (EC50 = 41.1 ± 5.6 μM) were diminished by L-NNA. L-Arginine prevented the action of L-NNA. N(G)-nitro-L-arginine also attenuated the gradient in the latency of the off response by shortening latencies in muscle from the caudad esophagus. It had no effect on cholinergic nerve-induced contraction of longitudinal esophageal muscle. These data support the hypothesis that NO or an NO-containing compound may be a mediator of NANC nerve-induced responses of the esophagus and LES.

Original languageEnglish (US)
Pages (from-to)G401-G406
JournalAmerican Journal of Physiology - Gastrointestinal and Liver Physiology
Volume261
Issue number3 24-3
DOIs
StatePublished - Jan 1 1991

Keywords

  • Enteric nervous system
  • Esophagus
  • Gastrointestinal motility
  • Smooth muscle

ASJC Scopus subject areas

  • Physiology
  • Hepatology
  • Gastroenterology
  • Physiology (medical)

Fingerprint Dive into the research topics of 'Nitric oxide: Mediator of nonadrenergic noncholinergic responses of opossum esophageal muscle'. Together they form a unique fingerprint.

  • Cite this