胆固醇对豚鼠离体胆囊肌收缩的急慢性效应

目的:探讨胆固醇(cholesterol)对豚鼠离体胆囊肌条收缩的影响及其机制。方法:采用张力换能器记录豚鼠离体胆囊肌条的收缩活动;观察胆固醇对胆囊肌条收缩的影响;观察胆固醇对胆固醇孵育胆囊肌条作用;并初步研究胆固醇对胆囊肌条的作用机制。结果:胆固醇对豚鼠离体胆囊肌条收缩有抑制作用;胆固醇孵育后,1×10-9mol/L,1×10-8mol/L,1×10-7mol/L各浓度胆囊收缩素(CCK)作用于胆囊肌条其张力效应值分别为(1.304±0.231)g、(1.748±0.287)g、(2.127±0.326)g,与正常胆囊肌条相比,效应值有显著性差异(P<0.05);CCK对胆囊离体肌条的作用可以部分被胆固醇抑制(变化为69.2%,P<0.05),胆固醇的影响可以部分被阿托品、尼莫地平抑制(变化分别为64.2%、62.1%,P<0.05);破坏胆囊Cajal间质细胞(ICC),收缩幅度与正常胆囊收缩幅度和频率有显著性差异(P<0.01),加入胆固醇无显著性差异(P>0.05)。结论:胆固醇孵育后,胆囊肌条对CCK的敏感性下降;胆固醇对离体胆囊平滑肌的收缩活动有抑制作用,其抑制效应是通过胆碱能受体、CCK受体及Ca2+介导。ICC是胆固醇对胆囊平滑肌作用途径中可能的中间环节。

Acute and Chronic Effects of Cholesterol on the Contraction of Extracorporeal Gallbladder Muscle Strips of Guinea Pigs

Objective: To investigate the acute and chronic effects of cholesterol on the contraction of extracorporeal gallbladder muscle strips of guinea pigs and their mechanism.Methods: The effects of cholesterol on the contraction of in vitro gallbladder muscle strip(group A) and gallbladder strip incubated in cholesterol for two hours(group B) were recorded by tonotransducer and compared.Results: Cholesterol could inhibit the contraction of extracorporeal gallbladder muscle strip partly.Compared with that in grou...