The effects and mechanisms of dimethylamiloride on cardiac function in cardiomegaly rat isolated hearts / 中国药理学通报

ABSTRACT

Aim To investigate the effects and mechanisms of DMA on cardiac function in cardiomegaly rat isolated hearts.Methods With Langendorff perfusion,the changes in the indicators reflecting cardiac function were observed in cardiomegaly rat isolated hearts.Its probable mechanism was explored with calcium channel blocker and sodium calcium exchange(NCX) blockers.Results DMA(0.5～2 ?mol?L~(-1))enchanced cardiac function and exerted positive effects on LVSP-LVDP,+dp/dt_(max)and-dp/dt_(max) in Langendorff-perfused cardiomegaly rat isolated hearts.The effects of DMA on cardiac function in cardiomegaly rat isolated hearts weren′t blocked by nicardipine-one of calcium channel blockers and were blocked by NiCl_2——one of sodium calcium exchange(NCX) blockers.Conclusion DMA can enhance systolic and diastolic function in cardiomegaly rat isolated hearts.By agitating NCX,DMA enhances cardiac function in cardiomegaly rat isolated hearts,independent of L-calcium channel.