Nitric oxide mediates inhibitory nerve input in human and canine jejunum.
Nitric oxide mediates inhibitory nerve input in human and canine jejunum.
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DOI：
10.1016/0016-5085(93)90407-4
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发表时间：
1993-02
期刊：
影响因子：
29.4
通讯作者：
Mark E. Stark;Anthony J. Bauer;Michel G. Sarr;J. Szurszewski
中科院分区：
文献类型：
--
作者：
Mark E. Stark;Anthony J. Bauer;Michel G. Sarr;J. Szurszewski
背景：一氧化氮（NO）可能是肠肌中的抑制性神经递质。本研究检查了其在人类和犬空肠中的作用。方法：从环形肌层同时记录机械和细胞内电活动。结果：在人类空肠中，神经刺激抑制机械活动并引起抑制性连接电位，该抑制性连接电位由最初的快速超极化和后期的持续超极化组成。 NO 抑制机械活动并引起模拟晚期超极化的剂量依赖性超极化。在犬空肠中，神经刺激抑制机械活动并引起仅由快速超极化组成的抑制性连接电位。NG-单甲基-l-精氨酸和NG-硝基-l-精氨酸减弱了这两个物种中神经介导的机械活动抑制。然而，合酶抑制剂对抑制性连接电位的影响在两个物种中是不同的。在犬空肠中，两种抑制剂均降低了初始快速超极化的幅度。在人空肠中，两种抑制剂仅减少晚期持续超极化。结论：NO通过不同的机制介导人和犬空肠环肌的神经抑制。
Background:Nitric oxide (NO) may be an inhibitory neurotransmitter in the intestinal muscle. The present study examined its role in human and canine jejunum.Methods:Mechanical and intracellular electrical activity were recorded simultaneously from the circular muscle layer.Results:In the human jejunum, nerve stimulation inhibited mechanical activity and evoked an inhibitory junction potential that consisted of an initial fast hyperpolarization followed by a late sustained hyperpolarization. NO inhibited mechanical activity and evoked a dose-dependent hyperpolarization that mimicked the late hyperpolarization. In the canine jejunum, nerve stimulation inhibited mechanical activity and evoked an inhibitory junction potential that consisted of only a fast hyperpolarization.NG-Monomethyl-l-arginine andNG-nitro-l-arginine attenuated nerve-mediated inhibition of mechanical activity in both species. However, the effect of the synthase inhibitors on inhibitory junction potentials differed in the two species. In canine jejunum, both inhibitors reduced the amplitude of the initial fast hyperpolarization. In human jejunum, both inhibitors reduced only the late sustained hyperpolarization.Conclusuions:NO mediates neural inhibition in circular muscle of both human and canine jejunum through different mechanisms.