Logo image
Back
Nitric oxide: mediator of nonadrenergic noncholinergic responses of opossum esophageal muscle
Journal article   Peer reviewed

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

J Murray, C Du, A Ledlow, J N Bates and J L Conklin
The American journal of physiology, Vol.261(3 Pt 1), pp.G401-G406
09/1991
DOI: 10.1152/ajpgi.1991.261.3.G401
PMID: 1887888

View Online

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. NG-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 microM]. L-Arginine, the substrate for NO synthase, reversed the inhibitory effect of L-NNA. Exogenous NO did not contact circular esophageal muscle. Both the amplitude (EC50 = 14.7 +/- 4.0 microM) and the latency of the off contraction (EC50 = 41.1 +/- 5.6 microM) were diminished by L-NNA. L-Arginine prevented the action of L-NNA. NG-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.
 Esophagus - drug effects Muscle, Smooth - innervation Nitric Oxide - antagonists & inhibitors Opossums Atropine - pharmacology Male Esophagus - physiology Muscle Tonus - drug effects Arginine - analogs & derivatives Dose-Response Relationship, Drug Muscle, Smooth - drug effects Animals Muscle Contraction - drug effects Arginine - pharmacology Female Muscle, Smooth - physiology Nitroarginine Muscle Relaxation - drug effects Esophagus - innervation In Vitro Techniques Nitric Oxide - metabolism

Details

Metrics

24 Record Views
188 Times Cited - Web of Science
Logo image