Morphological changes after combined administration of isoproterenol and K+,Mg2+-aspartate as a physiological Ca2+ antagonist.

The possibility of prevention of isoproterenol (ISO)-induced morphological changes by Ca2+ antagonists was investigated in the heart muscle of dogs. ISO in a dose of 7 mg/kg caused marked histochemical and electron microscopical necrotic changes. K+, Mg2+ aspartate (K,Mg-ASP) administered alone in a dose of 100 mg/kg changed slightly almost all cell components. K,Mg-ASP treatment applied prior to administration of ISO after 24 hours resulted in an improvement of the ultrastructure, which generally exhibited marked restoration resembling metabolic regeneration and/or enhanced metabolic activity.