缺血预处理与肝脏缺血再灌注时细胞凋亡变化的关系

目的 探讨缺血预处理与兔肝脏缺血再灌注时细胞凋亡变化的关系.方法 将兔分为假手术（SO）组、缺血再灌注（IR）组,缺血预处理（IP）组.后2组中分为6个亚组.缺血期均为60 min.缺血预处理为缺血前采用5 min缺血及5 min再灌注的方法.分别于再灌注结束后处死动物采取肝脏标本,SO组于手术后24 h采取肝标本.检测各组细胞凋亡指数.结果 在再灌注3～24 h时段时,IP各组与IR各组比较差异均有显著性（P〈0.01）,而在再灌注1、48 h时,两者比较差异无显著性（P〉0.05）.在IR组组内,在IR1h～IR24h组中,各组细胞凋亡值（AI）值均较上一组有显著性增加,而IR48h组与IR各组（IR1h组除外）比较,细胞凋亡值却出现显著性降低.而在IP组中,IP1h与其余IP各组比较,AI值差异有显著性（P〈0.01）,而其余IP各组的组间比较差异无显著性（P〉0.05）.结论 细胞凋亡现象主要存在于肝脏缺血再灌注早期,并且随着再灌注时间的延长,细胞凋亡现象逐渐加重,在再灌注24 h达到高峰.缺血预处理可明显抑制再灌注早期的细胞凋亡现象,从而减轻肝脏缺血再灌注损伤.

Relationship of varying apoptosis between ischemic preconditioning and hepatic ischemic reperfusion

Objective] To explore the apoptosis of hepatocytes during the ischemia reperfusion (IR), compared with which controlled by ischemic preconditioning(IP). Method] The rabbits were randomly divided into sham-operation(so), IR group and IP group. The latter two groups were farther divided into 6 subgroups and subjected to 60 minutes of ischemia. IP was achieved by ischemia for 5 minutes, followed by reperfusion for 5 minutes. In SO group, the rabbits were killed 24 hours after the operation and liver tissues were sampled. All groups' apoptosis index(AI) were cauculated. Results] AI significantly increased in IR3h~24h groups, compared with IP3h~24h groups (P <0.01), and the different of which was no significant between IR1h, 48 h groups and IP1h, 48 h groups. In the interior of IR groups, from the IR1h to IR24h groups, AI was significantly elevated compared with the precedent group (P <0.01, P <0.05), while the AI of IR48h group was significantly decreased compared with the other IR groups (P <0.01). In the interior of IP groups, compared with other subgroups, AI of IR1h group is significantly difference (P <0.01), and which is no difference among the rest of each IP groups. Conclusion] Apoptosis has occurred significantly in the forepart of IR which is increasing during IR. And it reachs the summit at 24 hours of reperfusion. IP may decrease the apoptosis of hepatocyte in the forepart of IR, so as to impair the injuries of liver.