一氧化氮对大鼠离体幽门窦环行肌的松弛作用

目的 ]观察一氧化氮对大鼠幽门窦环行肌运动的影响 ,并初步探讨其作用机制 .方法 ]制备幽门窦环行肌肌条 ,肌条的运动通过等张换能器记录于多导生理记录仪上 .利用铜和硝酸的化学反应制取一氧化氮 .结果 ]一氧化氮能抑制幽门窦环行肌的自发性收缩运动 ,而且这种抑制具有明显的量效关系 ;而在对照组 ,氮气对幽门窦环行肌运动无明显影响 ;一氧化氮抑制由乙酰胆碱引起的幽门窦环行肌的收缩 ,但一氧化氮引起的抑制效应不受乙酰胆碱、阿托品、酚妥拉明、心得安及河豚毒素的影响 ;一氧化氮的这种抑制作用能被氧合血红蛋白取消 .结论 ]一氧化氮能够模拟非肾上腺素能非胆碱能抑制神经对大鼠幽门窦环行肌运动的效应 ,一氧化氮的这种抑制效应是通过它对平滑肌细胞的直接作用实现的

Study of nitric oxide on antral circular muscle relaxation of rat stomach in vitro

OBJECTIVE To observe the effects of exogenous nitric oxide on antral circular muscle motility of rat's stomach, and to figure out preliminarily its mechanism. METHODS The antral circular muscle strips were prepared by the conventional method, and the mucosal layer was removed. An isotonic transducer on a polygraph recorded the motility of muscle strips. Exogenous nitric oxide was prepared by chemical reaction between nitric acid and copper. RESULTS The exogenous nitric oxide significantly inhibited the spontaneous motility and this inhibition had obvious dose effect relationship , but the nitrogen gas did not have the effects in the control group. The nitric oxide significantly inhibited acetylcholine induced contraction, on the contrary, the nitric oxide induced inhibition was not affected by acetylcholine, atropine, phentolamine, propranolol and tetrodotoxin. However, the inhibition was eliminated by oxyhemoglobin. CONCLUSION The nitric oxide mimics the effect of nonadrenergic, noncholinergic inhibitory nerve on gastric antral circular muscle motility in rats, and the inhibitory effect of nitric oxide is induced through its direct action on the smooth muscle cells.