缺血预处理联合后处理对大鼠肾缺血再灌注损伤的影响

目的 评价缺血预处理联合后处理对大鼠肾缺血再灌注损伤的影响.方法 健康雄性SD大鼠30只,体重250～280 g,随机分为5组(n=6):假手术组(S组)、缺血再灌注组(I/R组)、缺血预处理组(IP组)、缺血后处理组(IPo组)和缺血预处理联合后处理组(IP+IPo组).S组仅开腹,游离双侧肾脏,分离双侧肾蒂但不夹闭.采用夹闭双侧肾蒂45 min、再灌注6 h的方法 制备肾缺血再灌注模型.IP组夹闭双侧肾蒂5 min,再灌注5 min,反复3次,余操作同I/R组;IPo组夹闭双侧肾蒂45 min后,再灌注10 8,缺血10 s,反复3次,再灌注6 h.于再灌注6 h时,经心脏抽血后迅速处死大鼠取肾,测定血清肌酐(Cr)和尿素氮(BUN)的浓度;采用硫代巴比妥酸法测定肾组织丙二醛(MDA)含量,采用黄嘌呤氧化酶法测定肾组织超氧化物歧化酶(SOD)活性;光镜下观察肾组织病理学结果 ;TUNEL法检测肾组织凋亡细胞,计算凋亡指数(AJ).结果 与S组比较,其余各组血清Cr和BUN的浓度升高,肾组织SOD活性降低,MDA含量和AI升高(P<0.05);与I/R组比较,IP组、IPo组和IP+IPo组血清Cr和BUN的浓度降低,肾组织SOD活性升高,MDA含量和AJ降低(P<0.05),肾损伤减轻;与IP组和IPo组比较,IP+IPo组肾组织SOD活性升高,AI降低(P<0.05),肾损伤减轻.结论 缺血预处理联合后处理可减轻大鼠肾缺血再灌注损伤,较单独应用时效果好.

Effects of ischemic preconditioning combined with postconditioning on renal ischemla-reperfusion injury in rats

Objective To evaluate the effects of ischemic preconditioning combined with postconditioning on the renal ischemia-reperfusion (I/R) injury in rats.Methods Thirty healthy male SD rats weighing 250-280 g were randomly assigned into 5 groups ( n = 6 each) : group Ⅰ sham operation (group S) ;group Ⅱ I/R;group Ⅲ ischemic preconditioning (group IP);group Ⅳ ischemic postconditioning (group IPo);group Ⅴ IP + IPo.The rats were anesthetized with intraperitoneal 10% choral hydrate.Bilateral kidneys were exposed through a midline incision and bilateral renal pedicels were occluded for 45 min followed by 6 h reperfnsion.In group S,the kidneys were exposed,hut their pedicles were not clamped.In group IP,bilateral renal pedicels were occluded for 5 min followed by 5 min reperfusion,repeating 3 times,and the other procedures were performed using the same method as that of group I/R.In group IPo,45 min ischemia was followed by three 10 s episodes of ischemia at 10 s intervals for reperfusion.Blood samples were taken from the hearts to determine serum creatinine (Cr) and urea nitrogen (BUN) concentrations.After the animals were killed at 6 h of reperfnsion,kidneys were immediately removed for determination of MAD content,SOD activity,and apoptosis in the renal tubular epithelial cells (using TUNEL assay),and observation of histopathology with light microscope.Apoptotic index (AI) was calculated.Results Compared with group S,serum Cr and BUN concentrations,MDA content and AI were significantly increased,whereas SOD activity decreased in the other 4 groups.Serum Cr and BUN concentrations,MDA content and AI were significantly decreased,SOD activity increased,and injury to kidney was attenuated in group IP,IPo and IP + IPo as compared with group I/R.SOD activity was significantly increased,AI decreased,and injury to kidney was attenuated in group IP + IPo as compared with group IP and IPo.Conclusion Ischemia preconditioning and postconditioning can ameliorate the renal I/R injury in rats by improving the antioxidation of the kidney and inhibiting the apoptesis in the renal tubular epithelial cells,and the efficacy is better than that of either IP or IPo alone.