Abstract

The inotropic action of d-aldosterone on monkey isolated papillary muscles was investigated. The results obtained show that the immersion of such papillary muscles in Tyrode solution containing 1 x 10^-4 to 1 x 10^-4 µg/ml d-aldosterone resulted in a sustained positive inotropic response. The augmented contractions were not associated with a changed duration of contraction. The presence of 1 x l0^-4 µg/ml d-aldosterone depressed the contractions of other monkey papillary muscle preparations.

The positive inotropic action of d-aldosterone was not blocked by prior treatment of the papillary muscles with the, β-adrenergic blocking drug, pronethalol.