The effect of verapamil, isoproterenol, and dexamethasone on enzyme release and viability of coronary obstructed guinea-pig hearts.

In isolated perfused guinea-pig hearts decrease of coronary flow, release of creatine kinase (CK), severe arrhythmias and early standstill were produced by intracoronary application of plastic microspheres. 1 X 10(-9) g verapamil/ml perfusion fluid significantly decreased the CK release from these "ischemic" hearts. With 1 X 10(-8) g/ml a significant increase of the survival times was obtained. Dexamethasone strongly depressed the enzyme release from the coronary obstructed hearts. The survival times, however, were not prolonged. Isoproterenol significantly shortened the survival times. Very low concentrations decreased the CK release, whereas higher concentrations themselves provoked an enzyme release.