Mechanism of relaxation mediated by nitric oxide on human lower esophageal sphincter

• Published in: Zhong hua yi xue za zhi Vol. 86; no. 1; p. 31
• Main Authors: Wen, Shi-wang, Liu, Jun-feng, Gao, Li-ping, Tian, Zi-qiang, Wang, Qi-zhang, Li, Bao-qing
• Format: Journal Article
• Language: Chinese
• Published: China 03.01.2006
• Subjects: Aged; Arginine - pharmacology; Atropine - pharmacology; Dose-Response Relationship, Drug; Electric Stimulation; Enzyme Inhibitors - pharmacology; Esophageal Sphincter, Lower - drug effects; Esophageal Sphincter, Lower - physiology; Female; Humans; In Vitro Techniques; Male; Middle Aged; Muscle Relaxation - drug effects; Muscle Relaxation - physiology; Nitric Oxide - physiology; Nitric Oxide Donors - pharmacology; Nitric Oxide Synthase - antagonists & inhibitors; Nitroarginine - pharmacology; Nitroprusside - pharmacology; Tetrodotoxin - pharmacology
• ISSN: 0376-2491

To explore the mechanism of relaxation mediated by nitric oxide on the human lower esophageal sphincter (LES), and compare the difference in relaxation response between clasp fibers and sling fibers. 32 LES specimens were obtained from 32 patients with high-positioned carcinoma of the mid-esophagus, 12 males and 16 females, aged 55.9 +/- 9.3, during operation. The clasp fibers and sling fibers were isolated and suspended in perfusion tough. Electric field stimulation (EFS) was applied to the clasp and sling fibers in vitro. Nitric oxide synthase (NOS) inhibitor L-NNA, NOS substrate L-arginine, neurotoxin tetrodotoxin (TTX), and atropine were added respectively to observe their effects on the clasp and sling fibers under EFS. Sodium nitroprusside was added on the two kinds of smooth muscle stripes to observe its influence as well. EFS induced frequency-dependent relaxation to clasp fibers and some of sling fibers, which was inhibited by L-NNA in a concentration-dependent manner and was reversed by L-arginine p