Effect of prostacyclin (PGI2) on the mechanical activity of isolated longitudinal and circular muscle strips of guinea-pig stomach.
Effect of prostacyclin (PGI2) on the mechanical activity of isolated longitudinal and circular muscle strips of guinea-pig stomach.
复制标题
前列环素（PGI2）对豚鼠胃离体纵向和环形肌条机械活动的影响。
DOI：
--
复制
发表时间：
1983
影响因子：
--
通讯作者：
A. Rakovska
中科院分区：
文献类型：
--
作者：
K. Milenov;R. Nikolov;A. Rakovska
从豚鼠胃的胃底、胃体和胃窦以及幽门括约肌纵向和环形分离的肌条被置于器官浴中以记录其自发收缩性。测试了10（-9）至10（-6）M前列环素（PGI 2）的浓度，并与PGE 1、PGE 2、PGF 2 α和乙酰胆碱的作用进行了比较。此外，在肾上腺素能和胆碱能阻断剂、河豚毒素、吲哚美辛和PG拮抗剂SC-19220的存在下，研究了PGI 2效应的修饰。与PGE 1、PGE 2、PGF 2 α和乙酰胆碱一样，PGI 2增加胃底、胃体和胃窦的纵行肌条的张力，其作用不如PGE 1和PGE 2的作用强，但比PGF 2 α和乙酰胆碱的作用强。所有PG均呈剂量依赖性抑制胃窦环行肌和幽门括约肌的时相性收缩。在存在肾上腺素能和胆碱能阻断剂的情况下，这些作用没有显著变化，在存在河豚毒素的情况下也没有显著变化，因此可以解释为本质上是肌源性的。吲哚美辛的作用与PGI 2相反。它使PGI 2的对数浓度-效应曲线向右移动，抑制PGI 2的最大反应约50%。SC-19220可逆地抑制胃肌对PGI 2的自发张力和兴奋性反应。存在SC-19220时，PGI 2的浓度-效应曲线向右偏移。数据分析得出PGI 2的pA 2值为5.3，Schild图的斜率为1.23，这表明SC-19220是竞争性拮抗剂。
Muscle strips isolated in longitudinal and circular directions from the fundus, corpus and antrum, and from the pyloric sphincter of the guinea-pig stomach were placed in organ baths for recording their spontaneous contractility. Concentrations of the order of 10(-9) to 10(-6) M of prostacyclin (PGI2) were tested and compared with the effect of PGE1, PGE2, PGF2 alpha and acetylcholine. Furthermore, a modification of PGI2 effect was studied in the presence of adrenergic and cholinergic blocking agents, tetrodotoxin, indomethacin and the PG antagonist SC-19220. Like PGE1, PGE2, PGF2 alpha and acetylcholine, PGI2 increased the tone of the longitudinal strips from fundus, corpus and antrum, its effect being less potent than the effects of PGE1 and PGE2 and more potent than the effects of PGF2 alpha and acetylcholine. All the PGs inhibited the phasic contractions of the circular muscle of antrum and pyloric sphincter in a dose-dependent manner. These effects were not significantly changed in the presence of adrenergic and cholinergic blocking agents, nor in the presence of tetrodotoxin, and could therefore be interpreted as being myogenic in nature. Indomethacin exerted effects opposite to those of PGI2. It shifted the log concentration-effect curve for PGI2 to the right suppressing the maximum response of PGI2 by about 50%. SC-19220 reversibly inhibited the spontaneous tone and the excitatory responses of the gastric muscle to PGI2. The concentration-effect curves for PGI2 were shifted to the right in the presence of SC-19220. Analysis of the data gave the pA2 value for PGI2 5.3, the slope of Schild plot being 1.23, which suggests that SC-19220 is a competitive antagonist.