Inhibitory effects of O-benzyl-phosphocreatine ethyl ester in rabbit myocardium

O-benzyl-phosphocreatine ethyl ester (BPC-EE) applied in superfusion evoked a negative chronotropic effect in the sinus node strips. The drug reduced the action potential amplitude and duration, decreased the resting potential, and diminished the isometric tension in the atrial trabeculae and papillary muscles. BPC-EE acted in a dose-dependent manner, and at 2.5 mmol/l it abolished the electrical phenomena in the examined preparations. BPC-EE lowered also the ATP and phosphocreatine content and decreased the creation kinase activity in ventricular specimens. The last finding is probably responsible for the remaining effects of BPC-EE.