Na~+,K~+-ATP酶不参与慢性心衰豚鼠心肌细胞钙瞬变的减小

目的研究Na+,K+-ATP酶是否参与慢性心衰(CHF)豚鼠心肌细胞钙瞬变的减小。方法采用降主动脉缩窄(CDA)法和异丙肾(ISO)法建立豚鼠慢性心衰模型;酶解法急性分离左室心肌细胞;采用无机磷法测定心肌细胞膜Na+,K+-ATP酶活性,采用RT-PCR和Western blot检测CHF心肌Na+,K+-ATP酶α1、α2亚单位在mRNA水平和蛋白水平的表达。结果CDA法致心衰后Na+,K+-ATPα1、α2亚单位在mRNA水平均明显减少,ISO法α1明显减少,α2无变化;但两种方法致豚鼠CHF后,心肌细胞Na+,K+-ATP酶α1亚单位在蛋白水平的表达及酶活性均无改变。结论豚鼠CHF后钙瞬变的减小,没有Na+,K+-ATP酶的参与。

Na+, K+-ATPase may not involve in the decrease of calcium transient in cardiac myocytes from guinea pig with chronic heart failure

Aim To explore whether Na+,K+-ATPase involves in the decrease of calcium transient in cardiac myocytes from guinea pig with chronic heart failure(CHF).Methods The CHF model in guinea pig was produced by constricting the descent aorta(CDA) or subcutaneously injecting isoproterenol(ISO).Left ventricular myocytes were enzymatically isolated.Inorganic phosphorus method was used to determine cardiac sarcolemmal Na+,K+-ATPase activity.Then the expression of Na+,K+-ATPase α1 and α2 subunit in mRNA level and in protein level were detected with RT-PCR and Western blot,respectively.Results The expressions of Na+,K+-ATPase α1 and α2 subunit in mRNA level decreased in CDA CHF guinea pigs,α1 subunit also decreases but α2 subunit unchanges in ISO CHF guinea pigs.Both the Na+,K+-ATPase activity and the expression of Na+,K+-ATPase α1 subunit in protein level were unchanged in the two CHF guinea pigs.Conclusion Na+,K+-ATPase may not involve in the decrease in calcium transient induced by CHF.