SIDE-EFFECTS OF RAPAMYCIN IN THE RAT

The side effects of Rapamycin was evaluated by histopathological exami nation of the heart, kidneys, and eyes of treated Lewis rats. Rapamyci n was administered during 14 days by continuous intravenous infusions at doses of 0.5, 1.0, and 1.5 mg/kg/day. Focal myocardial infarction w as observed in three of five rats with Rapamycin given at 1.5 mg/kg/da y and two of 22 rats with 1.0 mg/kg/day. There were no sign of myocard ial toxicity at a Rapamycin dose of 0.5 mg/kg/day. The retina of one e ye of a rat treated at a dose of 1.5 mg/kg/day had a small area of foc al ischemic necrosis. The kidneys were normal at all doses.