Captopril: a protective agent in renal warm ischemia in rats.

Captopril, an angiotensin-converting enzyme inhibitor, was used as a protective agent before and after 90 min of renal warm ischemia in rats. At a dose of 1 mg/kg, it was able to lower the postoperative serum creatinine values significantly (from 6.3 to 2.5 mg% on the 2nd postoperative day) in unilaterally nephrectomized animals. Increasing the dose to 4 and 8 mg/kg or combining captopril with hypertonic mannitol (10 ml/kg of a 15% aqueous solution) did not improve these figures significantly. The same magnitude of protection was obtained when captopril was given either before or just after the ischemia. In terms of mortality the differences among unprotected and protected groups were very important: only 6 of 24 unprotected animals survived the 5th postoperative day while 42 of 44 protected animals survived.