Role of nitric oxide in the control of gastric motility within the nucleus ambiguus of rats
会议名称：《中国生理学会第23届全国会员代表大会暨生理学学术大会》
会议日期：2010年
学科分类：1001[医学-基础医学(可授医学、理学学位)] 10[医学]
基 金：supported by the National Science Foundation of China(No.30770277 30970354)
关 键 词：nucleus ambiguus gastric motility nitric oxide vagotomy
摘 要：正Background:NOS positive neurones and processes were seen in the nucleus ambiguous（NA）.Endogenous NO may reinforce the output activity of the medullary respiratory network,modulate heart rate by vagus nerves and modulate activity of oesophagus and pharynx.According to these reports we assume whether NO within NA modulates gastrointestinal motility.So in this study,we investigated that the role of nitric oxide in the control of the gastric motility within the nucleus ambiguus of rats.Material and methods:A latex balloon connected with a pressure transducer was inserted into the pylorus through the forestomach for continuous recording of the gastric motility.The amplitude,duration,frequency,and motility index of gastric contraction waves within 5 min before microinjection and after microinjection were measured.All data represent the mean±SE.Results: Microinjection of the NO-donor sodium nitroprusside（SNP;5 nmol,n=7） as well as of L-arginine（L-Arg;5 nmol, n=7） into the right NA significantly inhibited gastric motility by vagus nerves.For example,after SNP was microinjected into NA,gastric motility index decreased from 865.44±17.92（before microinjection） to 502.08±14.55（P0.01）. However,microinjection of the N（?）-nitro-L-arginine methyl esther（L-NAME;5 nmol,n=7）,the inhibitor of nitric oxide synthase,into NA significantly enhanced gastric motility.For example,after L-NAME was microinjected into NA,gastric motility index increased from 1003.80±88.88（before microinjection） to 1724.80±97.49（P0.01）.The pretreatment of intravenous injection hexamethonium bromide（0.5 mL/100 g,1.5 mg/100 g;n=6） abolished the inhibitory effect of SNP（5 nmol） on gastric motility.Conclusions:The data of these experiments suggest that NO inhibited gastric motility by activating the cholinergic preganglionic neurons in the NA and the inhibitory effect was mediated by the vagus nerves.