丙戊酸钠减轻猪心肺复苏后心脑损伤的作用及机制研究

The role and mechanism of sodium valproate in alleviating cardiac and cerebral injuries after cardiopulmonary resuscitation in pigs

目的探讨丙戊酸钠(sodium valproate,VPA)对猪心肺复苏(cardiopulmonary resuscitation,CPR)后心脑损伤的作用及机制。方法国产健康雄性白猪25头,体质量(37±3)kg,随机(随机数字法)为假手术组(Sham,n=6)、CPR组(n=10)与CPR+VPA组(n=9)。经右心室电极释放交流电诱发心脏骤停9 min,然后CPR 6 min,以此制备猪心脏骤停-复苏模型。CPR+VPA组在复苏后5 min利用微量输液泵经股静脉泵入VPA 150 mg/kg,持续1 h。于复苏后1 h、2 h、4 h和24 h,经股静脉采集血液标本,应用ELISA法检测心肌肌钙蛋白(cardiac troponin I,cTnI)、肌酸激酶同工酶(creatine kinase MB,CKMB)、神经元特异性烯醇化酶(neuron specifi c enolase,NSE)和S100B蛋白(S100B protein,S100B)。复苏后24 h对动物实施安乐死,迅速获取左室心肌和大脑皮层组织标本,应用Western blot法检测C/EBP同源蛋白(C/EBP homologous protein,CHOP)、半胱氨酸天冬氨酸蛋白酶12(caspase 12)和caspase 3的蛋白表达水平,TUNEL法检测细胞凋亡水平。三组间的计量资料比较,采用单因素方差分析。结果与Sham组相比,CPR组和CPR+VPA组复苏后心脑损伤标志物cTnI、CKMB、NSE和S100B的血清浓度均明显升高(均P<0.05)。与CPR组相比,CPR+VPA组cTnI和NSE在复苏1 h后、CKMB和S100B在复苏2h后的血清浓度显著降低(均P<0.05)。CPR组和CPR+VPA组复苏后心脑组织内质网应激凋亡相关蛋白CHOP、caspase 12和caspase 3表达较Sham组明显增加,细胞凋亡指数显著升高(均P<0.05)。而CPR+VPA组心脑组织的CHOP、caspase 12和caspase 3较CPR组明显减少,细胞凋亡程度显著降低(均P<0.05)。结论VPA具有减轻猪CPR后心脑损伤的作用,其机制可能与抑制内质网应激途径介导的细胞凋亡过程有关。

Objective To investigate the role and mechanism of sodium valproate(VPA)in cardiac and cerebral injuries after cardiopulmonary resuscitation(CPR)in pigs.Methods Twenty-fi ve healthy male domestic pigs,weighing(37±3)kg,were randomly divided into the sham group(n=6),CPR group(n=10),and CPR+VPA group(n=9).Cardiac arrest was induced by alternating current delivered via a pacing catheter in the right ventricle and untreated for 9 min,and then CPR was performed for 6 min,in which this procedure was used to establish the animal model of cardiac arrest and CPR.At 5 min after resuscitation,a dose of 150 mg/kg of VPA was infused with a pump via the femoral vein in 1 h in the CPR+VAP group.At 1 h,2 h,4 h and 24 h after resuscitation,blood samples were drawn from the femoral vein,and then used to measure the serum concentrations of cardiac troponin I(cTnI),creatine kinase MB(CKMB),neuron specifi c enolase(NSE),and S100B protein(S100B)by ELISA.At 24 h after resuscitation,the animals were euthanized,and then tissue specimens in the left myocardium and brain cortex were rapidly harvested to detect the expression levels of C/EBP homologous protein(CHOP),caspase 12,and caspase 3 by Western blot,and the rate of apoptotic cells was detected by TUNEL.Continuous variables were compared with one way analysis of variance among the three groups.Results(1)After resuscitation,cardiac and cerebral injury biomarkers including cTnI,CKMB,NSE,and S100B in serum were signifi cantly increased in the CPR and CPR+VPA groups compared with the Sham group(all P<0.05).The serum concentrations of cTnI and NSE starting 1 h after resuscitation and the serum concentrations of CKMB and S100B starting 2 h after resuscitation were signifi cantly decreased in the CPR+VPA group compared to the CPR group(all P<0.05).(2)Those proteins related to cell apoptosis mediated by endoplasmic reticulum stress,including CHOP,caspase 12,and caspase 3,were signifi cantly increased,and meanwhile apoptosis index was markedly elevated after resuscitation in the CPR and CPR+VPA groups compared with the Sham group(all P<0.05).Nevertheless,the expression levels of CHOP,caspase 12,and caspase 3 were signifi cantly decreased,and cell apoptosis was markedly reduced in the heart and brain after resuscitation in the CPR+VPA group compared to the CPR group(all P<0.05).Conclusions VPA can alleviate cardiac and cerebral injuries after CPR in pigs,and its mechanism may be possibly related to the inhibition of cell apoptosis mediated by endoplasmic reticulum stress.