Effects of propafenone on myocardium inotropism in isolated papillary muscle of guinea pig / 中国药理学通报

Aim To investigate the effects of propafenone on myocardium inotropism and explore it’s possible mechanism in isolated papillary muscle of guinea pig. Methods Developed tension (DT), maximum rate of contraction (+dT/dt_ max) and maxi-mum rate of relaxation (-dT/dt_ max) were measured during propafenone perfusion before and after administration of L-type calcium channel blocker, nicardipine and selective Na+/Ca 2+ exchanger inhibitor, KB-R7943. Results ①At concentration of 0.1,1,10,30 ?mol?L -1,propafenone attenuated DT from control (0.18?0.05) g to (0.14?0.03), (0.12?0.03), (0.08?0.02), (0.05?0.02) g respectively (P