肢体缺血中处理与缺血后处理改善严重失血性休克大鼠急性肾损伤作用的比较

Comparison of the Effects of Remote Ischemic Conditioning and Post-conditioning on Acute Kidney Injury in Rats with Severe Hemorrhagic Shock

目的:比较肢体缺血中处理与缺血后处理在严重失血性休克急性肾损伤中的作用。方法:38只清洁级大鼠随机分为4组:假手术组8只,缺血再灌注组、缺血中处理组、缺血后处理组各10只。假手术组不失血不输血,其余3组于60 min匀速抽出大鼠总血容量45%的血液,维持休克40 min后于40 min内匀速回输全部血液,复苏后4 h回笼,继续观察72 h。失血20 min时,缺血中处理组对大鼠肢体进行4个周期的阻断动脉血流5 min、松开再灌注5 min。缺血后处理组周期性阻断血流和恢复灌注同缺血中处理组,但于停止失血时进行。缺血再灌注组仅回输血液。于动物准备结束及复苏后4 h分别抽血检测肌酐(Cr)、尿素氮(BUN),72 h后取大鼠肾脏行病理检查,记录大鼠存活时间。结果:与假手术组相比,缺血再灌注组复苏后Cr、BUN明显升高,肾脏病理损伤较重,存活时间明显缩短;与缺血再灌注组相比,缺血中处理组、后处理组复苏后大鼠Cr、BUN均下降,肾脏病理损伤减轻,大鼠存活时间明显延长,尤以缺血中处理组明显(P<0.05)。结论:与缺血后处理相比,缺血中处理能使肾脏更早的对缺血再灌注进行适应,从而更好地减轻失血性休克缺血再灌注所致的急性肾损伤。

Objective:To compare the effects of remote ischemic conditioning and remote post-conditioning on acute kidney injury in rats with severe hemorrhagic shock.Methods:38 rats were randomly divided into four groups:sham group(n=8),ischemia reperfusion group(n=10),remote ischemic conditioning group(n=10),and remote ischemic post-conditioning group(n=10).The sham group did not lose blood or transfuse blood,while the other three groups drew out 45%of the total blood volume of the rats at 60 min,maintained the shock for 40 min,and then returned all the blood within 40 min.The rats were observed for 4h and then returned to the cage for 72 h.At 20 min of blood loss,the remote ischemic conditioning group blocked the arterial blood flow of the rat limbs for 4 cycles for 5 min,and then released and reperfusion for 5 min.The remote ischemic post-conditioning group was periodically blocked and perfusion was resumed in the same way as the remote ischemic conditioning group when bleeding was stopped.While the ischemia reperfusion group received only blood transfusion.Creatinine(Cr)and urea nitrogen(BUN)were detected at baseline and 4h after resuscitation.The survival time of rats was recorded,and rats’kidneys were taken for pathological examination after 72 hours.Results:Compared with the sham group,Cr and BUN increased,and renal injury was more serious in the ischemia reperfusion group.Compared with the ischemia reperfusion group,Cr and BUN decreased in the remote ischemic conditioning group and remote ischemic post-conditioning group,renal injury was reduced,and the survival time of rats was significantly prolonged,especially in the remote ischemic conditioning group(P<0.05).Conclusion:Compared with remote ischemic post-conditioning,remote ischemic conditioning can make the kidney adapt to ischemia reperfusion earlier,so as to better reduce the acute kidney injury caused by hemorrhagic shock and ischemia reperfusion.