RESUMEN
The effect of iloprost was investigated in an experimental model of cardiac damage in rats after isoprenaline (isoproterenol) treatment. Iloprost was administered by continuous subcutaneous infusion at a dose of 0.44 micrograms/kg body weight (b.w.)/min over a total period of 9 days. On day 8, 5 mg isoprenaline/kg b.w. was applied subcutaneously to induce the cardiac damage. The determinations of creatine kinase (CK, EC 2.7.3.2) and CK isoenzymes, lactate dehydrogenase (LDH, EC 1.1.1.27) and LDH isoenzymes as well as a-hydroxybutyrate dehydrogenase (a-HBDH, no EC) were performed 2, 6 and 24 h after isoprenaline application. Immediately after the last blood sampling, the animals were sacrificed and the hearts were examined histologically. Iloprost-pretreated animals showed a reduction in the rise in heart-specific isoenzymes CK-MB and LDH1-3 in the serum after isoprenaline application. A decrease in isoenzymes CK-BB and LDH4-5 in the serum was also observed in iloprost-pretreated rats. However, no difference could be detected histologically in the extent of myocardial necrosis between animals treated with isoprenaline alone or in combination with iloprost. These results suggest a biochemical cardioprotective effect of iloprost in this rat model after isoprenaline application and the lack of correlation with histological findings is discussed.