Ca2+-sensitizing effect of BM 14.478 on skinned cardiac muscle fibres of guinea-pig papillary muscle.

ABSTRACT

A concentration-dependent increase in force development was obtained with BM 14.478 (10(-9)-5 X 10(-4) M) in skinned fibres of guinea-pig papillary muscles. Guinea-pig papillary muscles are standard preparations for evaluating inotropic effects and they were also used in the present case for evaluating the positive inotropic effect of BM 14.478. We therefore conclude that a marked calcium-sensitizing effect contributes to the positive inotropic effect obtained with BM 14.478 even at very low concentrations.