[摘要]: 目的: 观察缺血后处理对大鼠肢体缺血再灌注（LIR）后肾组织细胞凋亡的影响，探讨其可能机制。方法: 30只SD大鼠随机分为对照组、缺血再灌注组（IR组）和缺血后处理加再灌注组（I-postC组），每组10只。建立大鼠肢体缺血再灌注（LIR）模型，即橡皮带环绕大鼠双后肢根部阻断血流4h再恢复血流灌注4h。对照组大鼠仅松弛环绕橡皮带不阻断血流，I-postC组大鼠则在再灌注前附加反复3次缺血5 min-再灌注5 min操作，即缺血后处理。全自动生化分析仪测各组大鼠血浆肌酐（Cr）、尿素氮（BUN）和C反应蛋白（CRP）水平；免疫组织化学法检测大鼠肾组织凋亡相关蛋白Bcl-2和Bax的表达，采用自动图像分析系统统计其定量结果并计算Bcl-2/Bax比值；TUNEL染色后在激光共聚焦显微镜下观察肾组织细胞凋亡情况，电镜下观察肾组织超微结构。结果: 与对照组比较，IR组和I-postC组大鼠血浆Cr、BUN和CRP水平均明显增高（P < 0.01）；与IR组比较，I-postC组大鼠血浆Cr、BUN和CRP水平均明显降低（P < 0.01）。与对照组比较，IR组和I-postC组大鼠肾组织中Bax和Bcl-2表达水平明显升高（P < 0.05或P < 0.01），Bcl-2/Bax比值降低（P < 0.05）；与IR组比较，I-postC组大鼠肾组织中Bax表达水平降低（P < 0.05），Bcl-2表达水平升高（P < 0.01），Bcl-2/Bax比值升高（P < 0.05）。激光共聚焦显微镜下观察，与对照组比较，IR组大鼠肾组织中凋亡细胞明显增多；与IR组比较，I-postC组大鼠肾组织中凋亡细胞明显减少。透射电镜下观察，对照组大鼠肾组织细胞结构清晰完整；IR组大鼠肾组织中肾近曲小管上皮细胞核固缩，溶酶体和致密颗粒沉积增多，线粒体数目减少，部分线粒体嵴断裂或模糊，肾小球足突细胞突起不规则、融合，有空泡现象，粗面内质网扩张；与IR组比较，I-postC组大鼠肾组织中肾小管上皮细胞及肾小球损伤有一定程度改善。结论: LIR可诱发大鼠肾组织细胞凋亡，缺血后处理可抑制肢体缺血再灌注后的肾细胞凋亡，对改善大鼠肾功能有一定作用。

[Abstract]: Objective: To observe the inhibitory effect of ischemic postconditioning (I-postC) on the apoptosis of renal cells after limb ischemia reperfusion(LIR) in the rats, and to investigate the possible mechanisms. Methods: Thirty SD rats were randomly divided control group, ischemia-reperfusion group(IR group) and I-postC group(n=10).4 h ischemia and 4 h reperfusion with the rubber band in two hind limbs of the rats were performed to establish the models. In control group, the rubber band around the limb was loose and the blood flow was not blocked. As for I-postC group, before perfusion, 5 min ischemia and 5 min reperfusion were performed in the rats and repeated 3 times named I-post C. The levels of blood creatinine (Cr), blood urea nitrogen(BUN) and C-reactive protein (CRP) in plasma of the rats in various groups were measured by automatic biochemistry analyzer. The expressions of Bcl-2 protein and Bax protein in renal were detected by immunohistochemical method, and its quantitative results were observed with automatic image analysis system and the ratio of Bcl-2/Bax was calculated.The apoptotic cells in kidney tissue were determined by terminal-deoxynucleotidy1 transferase-mediated d-UTP nick end labeling (TUNEL) under laser scanning confocal microscope(LSCM).The ultrastructures of kidney tissue were observed under electron microscope. Results: Compared with control group, the levels of Cr, BUN and CRP in plasma of the rats in IR group and I-postC group were increased(P < 0.05 or P < 0.01);compared with IR group, the levels of Cr, BUN and CRP in plasma of the rats in I-postC group were decreased(P < 0.01).Compared with control group, the expression levels Bax and Bcl-2 in kidney tissue of the rats in IR group and I-postC group were significantly increased (P < 0.05 or P < 0.01), and the ratios of Bcl-2/Bax were reduced(P < 0.05);compared with IR group, the expression level of Bax in kidney tissue of the rats in I-postC group was decreased (P < 0.05), the expression level of Bcl-2 was increased(P < 0.01), and the ratio of Bcl-2/Bax was increased(P < 0.05).Under laser confocal microscope, the number of apoptotic cells in kidney tissue of the rats in IR group was increased compared with control group; the number of apoptotic cells in I-postC group was decreased compared with IR group.Under transmission electron microscope, the changes in IR group were found as follows:renal proximal convoluted tubule epithelial cell nucleus vacuoles, increased lysosome and dense particle deposition, some mitochondria crest fracture or fuzzy; irregular and fusion, glomerular podocyte protuberance, mitochondrial cristae fracture and reducetion with vacuoles, rough endoplasmic reticulum expansion; the damage levels of renal tubular epithelial cells and glomerulus in I-postC group were improved compared with IR group. Conclusion: Limb ischemia reperfusion can induce the apoptosis of renal cells, I-postC can inhibit the apoptosis of renal cells, and it would be helpful to improve the kidney function.