Nerve-mediated nitric oxide production by opossum lower esophageal sphincter.
Antagonists of nitric oxide synthesis inhibit nerve-induced hyperpolarization and relaxation of muscle from the opossum lower esophageal sphincter. These studies test the hypothesis that nitric oxide is released during stimulation of intrinsic esophageal nerves. The intrinsic nerves were stimulated with an electrical field (10-sec trains of 1-msec, 30-V pulses delivered at 10 Hz). Nitric oxide production was measured with a DASIBI model 2108 Chemiluminescence NO Analyzer. NG-Nitro-L-arginine, an inhibitor of NO synthase, antagonized nerve-induced relaxation the lower esophageal sphincter. Nerve stimulation increased NO production from 0.50 +/- 0.04 nmol/min/100 mg tissue to 0.87 +/- 0.07 nmol/min/100 mg tissue (P < 0.01). NG-nitro-L-arginine inhibited both basal (0.030 +/- 0.09 nmol/min/100 mg tissue, P < 0.05 vs baseline) and stimulated (0.38 +/- 0.10 nmol/min/100 mg tissue, P < 0.01 vs stimulated). These studies support the hypothesis that nerve stimulation releases nitric oxide from the lower esophageal sphincter.
Murray
J
J
Department of Internal Medicine, University of Iowa College of Medicine, Iowa City 52242.
Bates
J N
JN
Conklin
J L
JL
D000594:Amino Acid Oxidoreductases / Q000037:antagonists & inhibitors; D000818:Animals; D004558:Electric Stimulation; D004943:Esophagogastric Junction / Q000294:innervation* / Q000378:metabolism*; D005260:Female; D066298:In Vitro Techniques; D008163:Luminescent Measurements; D008297:Male; D009252:NADPH Dehydrogenase / Q000037:antagonists & inhibitors; D009569:Nitric Oxide / Q000096:biosynthesis*; D019001:Nitric Oxide Synthase; D009893:Opossums; D010528:Peristalsis
D009569:Nitric Oxide; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D009252:NADPH Dehydrogenase