Abstract
We examined effects of changes in intracellular pH and chloride ion on isolated papillary muscle of guinea-pig ventricle subjected to simulated ischemia which was induced by covering the papillary muscle preparation with mineral oil, by measuring intracellular pH using ion-selective microelectrodes and by a conventional microelectrode technique. SITS and DIDS partly prevented shortening of action potential duration(APD) and intracellular acidosis induced by simulated ischemia. DIDS significantly prevented the shortening process of APD induced by chlomakarium (10 μM). DIDS and SITS significantly depressed Na current recorded from dispersed myocytes using whole cell patch-clamp technique. Present results provided a new finding that stilben-derivatives (DIDS and SITS) possess not only blocking action on ion-transporters, but also Na current depressant action on myocardium.
