增强Na^+-Ca^(2+)交换对大鼠心脏的正性变力作用及对哇巴因效应的加强(英文)  

Enhancement of sodium-calcium exchange induces positive inotropic action and potentiates ouabain effect in rat hearts

作　　者：赵画晨[1] 武冬梅[2] 崔香丽[1] 吴博威[1] 

机构地区：[1]山西医科大学生理教研室,太原030001 [2]山西医科大学药理教研室,太原030001

出　　处：《生理学报》2004年第4期476-480,共5页Acta Physiologica Sinica

基　　金：This work was supported by the National Natural Science Foundation of China (No.30170346).

摘　　要：本文采用大鼠乳头肌张力测定及离体心脏灌流技术,研究大鼠心肌Na+-Ca2+交换对乳头肌及离体灌流心肌变力性的影响。采用大鼠特异性Na+-Ca2+交换激动剂E-4031能剂量依赖性地增加大鼠乳头肌的发展张力(P<0.05,n=6)及离体心脏的心泵功能(P<0.05,n=4);特异性Na+-Ca2+交换抑制剂KB-R7943具有相反的效应,并可完全消除E-4031引起的正性变力作用。哇巴因(ouabain,0.5μmol/L)与E-4031(3μmol/L)联合使用,可使乳头肌发展张力由单独使用哇巴因时的0.25±0.03 g升高至0.29±0.04g(P<0.05,n=6);联合用药对大鼠离体心脏心泵功能的影响也强于哇巴因单独作用的效果。本研究结果证实,E-4031通过增强心肌Na+-Ca2+交换,对大鼠乳头肌和离体心脏产生正性变力作用;与哇巴因合用时,它们的正性变力作用有相加作用。To study the inotropic effect of enhanced Na+-Ca2+ exchange in the rat papillary muscles and isolated heart, the developed tension in the rat papillary muscles was measured and the left ventricular functions were assessed in the isolated rat heart. E-4031, a selective activator for Na+-Ca2+ exchange in rats, concentration-dependently increased the developed contractile tension in the rat papillary muscles (P<0.05, n=6) and the left ventricular functions in the isolated heart; KB-R7943, a selective Na+-Ca2+ exchange inhibitor, exhibited opposite effect. A combination of 0.5μmol/L ouabain and 3.0 μmol/L E-4031 resulted in a potentiation of the developed contractile tension of the rat papillary muscles from 0.25±0.03 g to 0.29±0.04 g. The combination also enhanced the augmentation of the left ventricular functions induced by ouabain. These results indicate that E-4031 exerts a positive inotropic effect on the rat papillary muscles and isolated heart via increasing the activity of Na+-Ca2+ exchange, and potentiates the positive inotropic effects of ouabain.

关 键 词：人鼠 乳头肌 肌力作用 钠钙交换 E-4031 KB-R7943 OUABAIN 

分 类 号：Q463[生物学—生理学]