银杏叶提取物对肾缺血再灌注损伤肾小管细胞凋亡调控基因表达的影响

目的 观察银杏提取物（Egb）对大鼠肾缺血再灌注后肾小管细胞凋亡调控基因bcl-2和bax表达的影响,探讨Egb肾保护作用的分子生物学机制.方法 用动脉夹夹闭大鼠双侧肾蒂45 min再灌注24 h方法制成急性肾缺血再灌注损伤模型.采用脱氧核苷酸末端转移酶介导的DNA原位末端标记技术检测细胞凋亡的情况.免疫组化检测Bcl-2、Bax表达.结果 缺血再灌注组较假手术组肾小管凋亡细胞数明显增多,Bcl-2、Bax表达均增强,Bax/Bcl-2比值增高;银杏叶提取物处理组较缺血再灌注组凋亡细胞数明显减少,Bcl-2表达进一步增强,而Bax表达减弱,Bax/Bcl-2降低.结论 银杏叶提取物可能通过影响Bcl-2、Bax表达,抑制细胞凋亡,从而发挥对缺血再灌注损伤肾脏的保护作用.

Effects of Ginkgo biloba extract on the expression of apoptosis-controlling genes in renal tubular cells during ischemia-reperfusion injury in rat kidney

Objective To study the effects of Ginkgo biloba extract(EGb) on the expression of Bcl-2 and Bax genes during renal ischemia-reperfusion(I/R) in rats.Methods The model of bilateral post-ischemic renal injury was set up by clamping renal pedicles for 45 minutes and allowing reperfusion for 24 hours.After that,the apoptosis of tubular cells was assessed by terminal-deoxynucleotidyl transferase mediated d-UTP nick end labeling(TUNEL) method,the expression of Bcl-2 and Bax was examined by immunohistochemistry.Results Compared with the results of sham operation group,significant increase of TUNEL positive cells,higher expression of Bax and Bcl-2,and increased Bax/Bcl-2 ratio were observed in I/R group(P<0.01).The EGb pretreatment group showed a significantly lower number of apoptotic positive nuclei than the I/R group(P<0.01),along with increased expression of Bcl-2,decreased expression of Bax and decreased Bax/Bcl-2 ratio.Conclusion Inhibition of apoptosis and regulation of Bcl-2/Bax expression may be responsible for the renal protective effects of EGb in the rats undergoing renal ischemia-reperfusion.