Prostacyclin prevents ischemia-induced increase of lactate and cyclic AMP in ischemic myocardium

The effect of prostacyclin (PGI2, 0.5 nmol . kg-1 . min-1,i.v.) on myocardial metabolism was studied in cats subjected to 5 h of myocardial ischemia (MI) and compared to vehicle-treated MI cats. MI was followed by a 52% decrease in ATP and a concomitant increase (2-3 fold) in lactate and lactate/pyruvate ratio in the severely ischemic area. PGI2 prevented this increase in lactate with an unchanged ATP and lactate/pyruvate ratio. Moreover, PGI2 abolished the ischemia-induced in myocardial cAMP. It is concluded, the PGI2 exerts its beneficial actions on ischemic myocardium partly via cAMP-linked mechanisms.