Experimental study on the effects of aprotinin on myocardial ischemia and reperfusion.

Direct effects of a high-dose aprotinin on the normally perfused hearts and the myocardial protection after ischemia and reperfusion were investigated in an isolated working rat heart model. In trial I, hearts had no ischemia and were perfused with either K-H solution or the K-H solution containing aprotinin (200 KIU/ml) for 55 min. No statistically significant difference was observed in hemodynamics between the two groups. In trial II, hearts were exposed to 150 min period of global ischemia at 15 degrees C with 4 degrees C multidose St. Thomas' II solution (STS). The control group I received normal K-H solution; the group II was treated with the solution with aprotinin added. The group III was similar to the group I and received the STS enriched with aprotinin. On reperfusion, the recovery of hearts in group III was significantly better than those of the group I and II, as reflected by better hemodynamics and myocardial ATP levels and milder myocardial ultrastructural injury. There was no difference between the group I and II. These results suggest that the aprotinin a dose of 200 KIU/ml has no harmful effects on normally perfused hearts and has a marked myocardial protective effect on the prolonged myocardial ischemia when used in cold crystalloid cardioplegia.