Cyclin D1在大鼠肝缺血预处理和缺血再灌注损伤中早期复灌的表达

Expression of cyclin D1 in rats liver ischemic preconditioning and ischemic reperfusion injury during early reperfusion

目的观察缺血预处理对大鼠肝缺血再灌注损伤复灌早期细胞增殖与Cyclin D1表达的影响,探讨缺血预处理保护作用的机制。方法54只SD大鼠随机分成缺血再灌注组(IR)、缺血预处理组(IP)和假手术组(SO),利用肝原位部分缺血再灌注模型,于复灌后0、1、2、4 h取材,应用流式细胞仪,检测各组肝细胞Ki67抗原表达,同时应用Western blot法检测各组蛋白表达的变化。结果与IR组相比,在复灌后0、1 h,IP组肝细胞Ki67表达率明显增高[(28．86±6．34)％比(19．40±5．35)％,(46．82±9．80)％比(22．40±5．08)％,P＜0．05],同时可见IR组复灌后2h Cy- clinD1蛋白始有表达,而IP组在复灌开始时即有表达。结论缺血预处理可促进肝细胞在缺血再灌注损伤后早期细胞增殖与Cyclin D1的表达,可能是其对缺血再灌注损伤起到保护作用的机制之一。

Objective To observe the effect of ischemic preconditioning on the rats liver cell proliferation and the cyclin D1 expression during early reperfusion after ischemia/reperfusion injury. Methods Fifty-four SD rats were randomly divided into ischemic preconditioning group （IP）, ischemia/reperfusion group （IR） and sham operation group （SO）. The model of partial liver ischemia/reperfusion was used and the liver cells were collected at 0,1,2 and 4 h after ischemia/reperfusion. In each group, the expression of Ki67 antigen was detected by flow cytometry, and the expression of cyclin D1 protein detected by Western blot. Results The expression rate of Ki67 in hepatic cells of IP group at 0 and 1 h after reperfusion was significantly higher than that of group [ （28.86 ± 6.34） vs （ 19.40 ± 5.35）, （46.82 ± 9.80） vs （22.40 ± 5.08 ） respectively, P 〈 0.05 ]. The cyclin D1 protein was expressed in I R group at 2 h after reperfusion, while it was expressed immediately after reperfusion in IP group. Conclusion Ischemic preconditioning before hepatic ischemia/reperfusion could promote cell proliferation and the cyclin D1 expression in the early reperfusion, which may be one of the mechanisms by which ischemic preconditioning protects ischemia/reperfusion injury.