【摘要】 目的观察牛磺酸(taurine)对链脲菌素(STZ)引起胰岛细胞凋亡及胰岛素分泌与BCL-xL和BAX蛋白表达变化的影响。方法用体外单层培养的方法,培养已存活3~5 d的W istar乳鼠的胰岛细胞,在瑞氏染液染色后光镜下分别检测STZ使用前后胰岛凋亡细胞百分率、DNA片段、培养液中NO2-/NO3-含量、NOS活性、胰岛素分泌以及BCL-xL和BAX的变化,并进一步观察牛磺酸对上述指标的影响。结果STZ可诱导胰岛细胞凋亡率明显增加,从(4.0±0.7)%升至(40.5±5.7)%,使DNA明显片段化、胰岛素分泌明显降低、BCL-xL表达下降、BAX表达增强(P<0.01)和NO2-/NO3-含量升高,但NOS活性变化不明显。牛磺酸能有效抑制STZ引起的上述指标(NO2-/NO3-含量除外)的变化,该效应具有一定的剂量依赖性。结论牛磺酸能够改善STZ诱导的胰岛细胞凋亡,其机制可能与下调BAX/BCL-xL比例有关,而与NO2-/NO3-含量及NOS活性关系不大。更多还原

【Abstract】 Objective To investigate the inhibition effect of taurine on the apoptosis of isolated pancreatic islet cells insulin secretion,the expression of BCL-xL and BAX induced by streptozotocin.Methods Isolated pancreatic islet cells from Wistar rats of 3 to 5 days were incubated in monolayer in vitro.（NO₂^-/NO₃^-） production,NOS activity,insulin secretion,expression of BCL-xL and BAX,apoptotic rate of islet cells after and DNA fragmentation in pancreatic islet cells after incubation with streptozotocin were measured,and the potential effects of taurine was investigated.Results Streptozotocin induced a significant increase in apoptotic rate of pancreatic islet cells（from（4.0±0.7）% to（40.5±5.7）%）,DNA ladder appearance,a decrease of insulin content,up-regulation of the expression of BAX and down-regulation of the expression of BCL-xL（P<0.01） these effects were partially blocked by taurine.Streptozotocin also induced an increase in （NO₂^-/NO₃^-） production but an indistinct change of NOS activity,that could not be blocked by taurine.Conclusion Taurine can attenuate the streptozotocin-induced pancreatic islet β cells apoptosis,the mechanisms of which may be the down-regulation of BAX/BCL-xL proportion and not related to（NO₂^-/NO₃^-） and NOS activity change.更多还原