Suppression of Corticosteroid Production in the Dog by Monase

Summary

Clinical toxicity encountered with 3-(2-aminobutyl)-indole acetate (Monase) has included syncope and hypotension. Hence the effects of this compound on adre-nocortical function were studied. A sharp decrease in adrenocortical steroid output of dogs under pentobarbital anesthesia was seen shortly after intravenous injection of this compound. Doses of 5 mg/kg and 10 mg/kg were used. Adrenal venous blood levels of 17-hydroxycorticosteroids returned to normal at 1-2 hours after drug administration. ACTH infusion as well as ether anesthesia prevented this corticosteroid depressant action. After hypophysectomy, Monase did not alter the increased corticosteroid secretion induced by exogenous ACTH. The data suggest that the pharmacologic action of Monase in reducing 17-hydroxycorticosteroid secretion in intact dogs is a result of suppression either of formation or release of ACTH in dogs under pentobarbital anesthesia.

The able assistance of Mr. Donald L. Barber is gratefully acknowledged. We wish to thank the Upjohn Co., Kalamazoo, Mich., for generous supplies of Monase.