外源性CO对失血性休克复苏大鼠急性肾损伤时细胞凋亡的影响

Effect of exogenous carbon monoxide on cell apoptosis during acute renal injury induced by hemorrhagic shock and resuscitation in rats

目的评价外源性CO对失血性休克复苏(HSR)大鼠急性肾损伤时细胞凋亡的影响。方法清洁级健康雄性SD大鼠48只,9~10周龄,体重350~400 g,采用随机数字表法分为4组(n=12):假手术组(S组)、HSR组(H组)、HSR+CORM-3组(HC组)和HSR+iCORM-3组(HiC组)。失血性休克通过股静脉放血至MAP为30~35 mmHg维持45 min,将收集的血液在15 min内回输体内达到初始血压水平作为复苏,必要时输注生理盐水,建立HSR模型;HC组和HiC组在HSR模型进行液体复苏时分别加入CORM-3和iCORM-34 mg/kg(CORM-3在超净台中静置24 h,充分释放CO后作为对照)进行处理;S组只进行股静脉、股动脉穿刺置管。于复苏后3 h时采集大鼠尾静脉血样,测定血清尿素氮(BUN)和肌酐(Scr)浓度;于复苏后12 h时处死大鼠取肾脏组织,Western blot法测定Bcl-2、Bak及cleaved caspase-3的表达,TUNEL染色检测肾脏细胞凋亡情况,观察病理学结果并行损伤评分。结果与S组比较,H组、HC组和HiC组血清BUN、Scr浓度、病理学损伤评分和肾脏细胞凋亡率升高,Bcl-2/Bak比值降低,cleaved caspase-3表达上调(P<0.05);与H组比较,HC组血清BUN、Scr浓度、病理学损伤评分和肾脏细胞凋亡率降低,Bcl-2/Bak比值升高,cleaved caspase-3表达下调(P<0.05);与HC组比较,HiC组血清BUN、Scr浓度、病理学损伤评分和肾脏细胞凋亡率升高,Bcl-2/Bak比值降低,cleaved caspase-3表达上调(P<0.05);H组和HiC组比较,上述指标差异无统计学意义(P>0.05)。结论外源性CO改善HSR大鼠急性肾损伤的机制可能与抑制细胞凋亡有关。

Objective To evaluate the effect of exogenous carbon monoxide(CO)on cell apoptosis during acute renal injury induced by hemorrhagic shock and resuscitation(HSR)in rats.Methods Forty-eight clean-grade healthy male Sprague-Dawley rats,aged 9-10 weeks,weighing 350-400 g,were divided into 4 groups(n=12 each)by a random number table method:sham operation group(S group),HSR group(H group),HSR plus CORM-3 group(HC group)and HSR plus iCORM-3 group(HiC group).Mean arterial pressure was maintained at 30-35 mmHg for 45 min by withdrawing blood from the femoral vein,and the shed blood was re-transfused within 15 min to reach the initial blood pressure for resuscitation.Normal saline was infused when necessary,and the model of HSR was established.CORM-34 mg/kg and iCORM-34 mg/kg were added during resuscitation in HC group and HiC group,respectively.Only femoral vein and artery puncture was performed in S group.Blood samples were obtained from the tail vein at 3 h after resuscitation for measurement of serum urea nitrogen(BUN)and creatinine(Scr)concentrations.Rats were sacrificed at 12 h after resuscitation,and renal tissues were obtained for determination of the expression of Bcl-2 and Bak protein and cleaved caspase-3(by Western blot)and cell apoptosis(by TUNEL).The damage to the renal tubules was assessed by paller assay after HE staining.Bcl-2/Bak ratio and apoptosis rate were calculated.Results Compared with group S,the serum BUN and Scr concentrations,paller scores,and apoptosis rate were significantly increased,Bcl-2/Bak ratio was decreased,and the expression of cleaved caspase-3 was up-regulated in H,HC and HiC groups(P<0.05).Compared with group H,the serum BUN and Scr concentrations,paller scores,and apoptosis rate were significantly decreased,Bcl-2/Bak ratio was increased,and the expression of cleaved caspase-3 was down-regulated in group HC(P<0.05).Compared with group HC,the serum BUN and Scr concentrations,paller scores,and apoptosis rate were significantly increased,Bcl-2/Bak ratio was decreased,and the expression of cleaved caspase-3 was up-regulated in group HiC(P<0.05).There was no significant difference in the indexes mentioned above between group H and group HiC(P>0.05).Conclusion The mechanism by which exogenous CO improves acute kidney injury may be related to inhibiting cell apoptosis in a rat model of HSR.