大鼠移植胰腺冷缺血再灌注后细胞凋亡的变化

Apoptosis induced by cold ischemia and reperfusion after pancreas transplantation in rats

目的 探讨移植胰腺冷缺血再灌注后胰腺细胞凋亡的变化过程。方法 6 5只SD大鼠随机分成 7组 :假手术组 ,冷缺血 2h组 ,冷缺血 2h再灌注 1、3、6、9、12h组。通过HE染色后光镜及电镜观察各组的胰腺组织的病理变化 ;采用脱氧核糖核苷酸末端转移酶介导的缺口末端标记法(TUNEL)检测凋亡细胞的分布及计数。结果 胰腺移植后早期即可观察到细胞凋亡的典型改变 ,胰腺冷缺血再灌注后发生凋亡的高峰期为再灌注后 3h[AI为 (9.4 6± 2 .91) % ,P <0 .0 1) ,再灌注 6h较 3小时细胞凋亡有所减少 [AI为 (5 .74± 1.6 6 ) % ,P <0 .0 1],再灌注 9h及 12h细胞凋亡进一步减少 [AI分别为 (3.6 0± 1.6 4 ) %及 (3.2 6± 1.35 ) % ,P <0 .0 5 ]。结论 细胞凋亡是胰腺移植后的早期事件 ,移植胰腺冷缺血再灌注后早期主要的死亡方式是凋亡 ;移植胰腺冷缺血再灌注后的凋亡高峰发生在再灌注后 3h。

Objective To document the time course of apoptosis in acinar cells before and after pancreas graft implantation in the rat. Methods Pancreas transplantation was performed in male SD rats after 2 hours of cold ischemia (n=5 in each groups). Rats (n=65) were randomized into 7 groups: sham operation group, cold ischemia group (as control), 1 h, 3 h, 6 h, 9 h, 12 h group. The pathologic characters of pancreatic tissue were observed under light and electronic microscope of post implustation; apoptotic cells were stained by the terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) technique. Results The pathologic changes of apoptotic cells were found in early phase after pancreas transplantation. The peak of apoptosis pancreas cells occurred 3 hours after reperfusion [AI (9.46±2 91)%, P<0.01 vs controls, pancreas fixed after 2 hours of ischemia] At six hours after reperfusion, the number of apoptotic pancreas cells was lower than that 3 hours after reperfusion [AI (5.74±1.66)%, P<0.01 vs controls], with a further decline at 9 hours [AI (3.60 ±1.64)%, P<0.05 vs controls] and 12 hours after reperfusion [AI (3.26±1.35)%, P< 0.05 vs controls). Conclusions Apoptosis of pancreas cells after posttransplant pancreas reperfusion is a very early event. The mode of cell death in early phase after pancreas transplantation is apoptosis,but not necrosis. The peak of apoptotic pancreas cells occurred 3 hours after reperfusion.