西咪替丁和雷尼替丁对大鼠小肠纵行肌条作用机理的探讨

The possible mechanism of cimetidine and ranitidine on contractile of isolated small intestinal strips in rats

目的 本研究取大鼠各部位小肠纵行肌条 ,初步探讨西咪替丁和雷尼替丁对大鼠小肠各部位纵行肌条的作用机理。方法 取大鼠小肠各部位纵行肌条 ,放入盛满krebs液的灌流肌槽中 ,加入药物 ,记录其收缩活动的变化。结果 酚妥拉明减弱西咪替丁对回肠肌条收缩波平均振幅的减小作用 ,阿托品不影响雷尼替丁对回肠肌条的兴奋作用 ,六烃季胺、普萘洛尔、吲哚美辛、L NNA不影响西咪替丁和雷尼替丁对各肌条的抑制作用。结论 西咪替丁对回肠肌条的抑制作用可能部分由肾上腺素能α受体介导 ,雷尼替丁对回肠肌条的兴奋作用可能与胆碱能M受体无关 ,西咪替丁和雷尼替丁对各肌条的抑制作用可能与H2 受体无关。

Objective To study the mechanism of cimetidine and ranitidine on contractile activity of isolated small intestinal longitudinal strips in rats.Methods One end of the strips was fixed in a tissue chamber while the other end was connected to an isometric force transducer,then motility of the strips were recorded.Results Phentolamine partly inhibit the effect of cimetidine on the mean contractile amplitude of the ileal strips,atropine do not block excitatory of ranitidine on the ileal strips,hexamethonium?propranolol?indomethacin and L_NNA do not block the effect of cimetidine and ranitidine on each small intestinal longitudinal strips.Conclusion The inhibition of cimetidine on the ileal strips may be mediated via a receptor,the excitatory of ranitidine on the ileal strips in rats may not be mediated via M receptor,the inhibition of cimetidine and ranitidine on each small intestinal longitudinal strips may not be mediated via H 2 receptor.