适度提高血钾浓度可改善心肺复苏大鼠脑组织线粒体功能

Moderately elevating blood potassium concentration can improve mitochondrial function of brain tissue in cardiopulmonary resuscitation rats

目的探讨心肺复苏(CPR)时适度提高血钾浓度能否改善脑组织线粒体功能。方法80只SD大鼠随机分为假手术组(SH组)、生理盐水组(NS组)及氯化钾低(LK组)、中(MK组)和高剂量组(HK组),每组16只。经食道电刺激诱导心室颤动建立心跳骤停(CA)/CPR模型。CA后6 min启动CPR,同时经静脉注射生理盐水或氯化钾。观察并记录自主循环恢复(ROSC)后平均动脉压(MAP)、血钾,以及ROSC后24 h的神经功能缺损评分(NDS)、海马组织HE染色的细胞形态、海马组织ATP含量、Na^(+)/K^(+)-ATP酶活性、呼吸链复合物Ⅰ/Ⅱ/Ⅲ/Ⅳ的活性。结果与NS组相比,MK组、HK组ROSC后1 min、10 min血钾升高(P<0.05)。与NS组相比,MK组复苏后MAP变化差异无统计学意义,ROSC后24 h NDS升高(P<0.05),而HK组ROSC后8 min内的MAP明显下降(P<0.05),ROSC后24 h NDS无改善。与NS组相比,LK组海马组织呼吸链复合物Ⅲ活性升高,ATP生成增加(P<0.05);与NS组相比,MK组ROSC后24 h呼吸链复合物Ⅰ/Ⅱ/Ⅲ活性升高,ATP生成增加、Na^(+)/K^(+)-ATP酶活性升高(P<0.05),ROSC后24 h海马区细胞形态改善;与NS组相比,HK组呼吸链复合物Ⅲ活性升高(P<0.05)。MK组各评估指标改善最明显。结论CPR早期适度升高血钾可改善脑组织线粒体功能,减轻脑缺血再灌注损伤。

Objective To explore whether moderately hyperkalemia can improve mitochondrial function of brain tissue during cardiopulmonary resuscitation(CPR)in rats.Methods Eighty rats were randomly divided into five groups:the sham(SH)group,the normal saline(NS)group,the low dosage of potassium chloride(LK)group,the mid-dosage of potassium chloride(MK)group and the high-dosage of potassium chloride(HK)group,with 16 rats in each group.Cardiac arrest(CA)/CPR model was established by transesophageal electrical stimulation to induce ventricular fibrillation.Rats were received equal volume of normal saline and the corresponding dose of potassium chloride via intravenous injection when CPR was initiated at 6 min after CA.The mean arterial pressure(MAP)and the blood potassium concentration were detected after return of spontaneous circulation(ROSC).The neurological deficit scores(NDS),the changes of cell morphology of hippocampal tissue,the content of adenosine-triphosphate,the activity of Na^(+)/K^(+)-ATP enzymes,the respiratory chain complex(Ⅰ/Ⅱ/Ⅲ/Ⅳ)of the hippocampal tissue at 24 h post ROSC were recorded and observed between different groups.Results Compared with the NS group,the blood potassium was significantly higher in the MK group and the HK group at 1 min and 10 min post ROSC(P<0.05).Compared with the NS group,the MAP after ROSC was not significantly affected,and the NDS was significantly increased at 24 h after ROSC in the MK group(P<0.05).Compared with the NS group,the MAP within 8 min after ROSC was significantly decreased(P<0.05),and the NDS was not significantly improved at 24 h post ROSC in the HK group.Compared with the NS group,the activity of hippocampal respiratory chain complex Ⅲ was increased in the LK group,and the content of ATP was increased(P<0.05).Compared with the NS group,the activity of respiratory chain complex(Ⅰ/Ⅱ/Ⅲ),the content of ATP and the activity of Na^(+)/K^(+)-ATP enzyme at 24 h post ROSC were increased in the MK group(P<0.05),and hippocampal cell morphology was improved 24 h after ROSC.Compared with the NS group,the activity of respiratory chain complex Ⅲ increased in the HK group(P<0.05).The MK group showed the most obvious improvement in each evaluation index.Conclusion Moderately elevating blood potassium at onset of CPR can improve mitochondrial function and alleviate cerebral ischemia-reperfusion injury in CPR.