A selective concentration-dependent dysrhythmogenic and antidysrhythmic action of prostaglandins E2, F2 alpha and I2 (prostacyclin) on isolated rat hearts.

Prostaglandins (PGs) E2, F2 alpha and I2 were examined for their effects on the electrical and mechanical activities of isolated rat, rabbit and guinea-pig hearts. All PGs produced dysrhythmias in rat hearts at low concentrations only, while higher concentrations were antiarrhythmic. Guinea-pig hearts were less responsive while rabbit hearts were completely resistant.