PROLONGED RAT-HEART ALLOGRAFT SURVIVAL AFTER TREATMENT WITH ANGIOTENSIN-CONVERTING ENZYME-INHIBITOR OR A CALCIUM-ANTAGONIST

The effect in vivo of the angiotensin converting enzyme (ACE) inhibito rs captopril and enalapril and the calcium antagonist verapamil was st udied in an experimental model using rat heart allografts. Daily post- transplant treatment of recipient rats (DA strain) with verapamil (75 mg kg(-1) day(-1)) or captopril (40 mg kg day) significantly prolonged survival of allografts from donors (PVG/c strain) when compared with an untreated control group (p < 0.05). No synergistic effect was obser ved when the two drugs were used for combined treatment. An equipotent does of enalapril (12.5 mg kg(-1) day(-1)) caused no change in allogr aft survival of statistical significance. The results support the hypo thesis that verapamil and captopril have effects on the immune reactiv ity in vivo, and that this is not a characteristic shared by all ACE i nhibitors.