【摘要】 目的探讨心衰后大鼠心肌的Na+-K+泵活性及其α亚基的变化。方法建立大鼠多柔比星(adriamycin,ADM)心衰模型。以酶解法急性分离大鼠左室心肌细胞,以膜片钳技术记录Na+-K+泵电流,并以Western blot技术检测Na+-K+泵α亚基的表达。结果 ADM致大鼠心衰后Na+-K+泵电流密度显著下降,由(0.507 0±0.062 97)pA/pF降到(0.210 6±0.048 90)pA/pF,且拟合曲线显示主要为高亲和力泵发生了改变,其K值由6.74×10-8mol.L-1升至2.97×10-7mol.L-1;Westernblot检测结果也进一步表明低亲和力α1亚基蛋白表达无明显改变,而高亲和力α2亚基蛋白表达则明显下降。结论心衰可通过减少Na+-K+泵高亲和力α2亚基表达而降低大鼠心肌Na+-K+泵活性。更多还原

【Abstract】 OBJECTIVE To investigate the changes of the activity of Na+/K+-pump and the expression of Na+/K+-pump α isoforms in heart failure(HF)rats.METHODS The model of HF was established by adriamycin(ADM).Left ventricular myocytes were enzymatically isolated.Whole-cell patch-clamp technique was performed to record Na+/K+-pump current(Ip),and Western blot was used to detect the expression of the Na+/K+-pump α1 and α2 isoforms.RESULTS The density of Na+/K+-pump current was significantly decreased from(0.507 0±0.062 97) to(0.210 6±0.048 90) pA/pF in HF rats.ΔIp- relation indicated that the high affinity Na+/K+-pump was changed in HF rats,with the K value changed from 6.74×10-8 to 2.97×10-7 mol·L-1.Compared with normal rats,the expression of α1 isoforms in HF rats was not changed,but the α2 isoforms showed a significant decrease.CONCLUSION In HF rats,the expression of α2 isoforms is reduced which is related to the decreased activity of Na+/K+-pump.更多还原