EFFECTS OF CORTISONE ACETATE ON MILK PRODUCTION AND MAMMARY INVOLUTION IN PARTURIENT RATS1

Abstract

Two similar experiments were performed on 68 parturient rats to determine the effects of cortisone acetate On lactation and mammary involution. The lactational response was measured by the effect on growth rate of the litters during the first 18 days post-partum. In the first experiment, 0.5 mg of cortisone acetate daily elicited a significant increase in average litter weight gain over the control litters. A dose level of 1.0 mg of cortisone acetate daily produced a slight but insignificant gain in average litter weight over control litters, despite a loss of over 15% in body weight by the mother rats. In the second experiment, daily doses of 0.5 or 1.0 mg of cortisone acetate, induced significant litter weight gains over control litters. When litters were removed on the 18th day postpartum, and cortisone acetate injections were continued for an additional 10 days, mammary involution was significantly retarded.