Effect of Reserpine on Prolactin Content of Rabbit Pituitary. ∗

Summary

1. A single intravenous injection of 1 mg reserpine kilo body weight into 5 mature female rabbits, followed by sacrifice 1 week later, resulted in at least a 5-fold increase in pituitary prolactin content over 5 controls. There was no evidence that reserpine induced mammary growth or lactation. 2. Subcutaneous injections of 0.2 mg estradiol daily for 10 days into 6 rabbits elicited 1 week later at least a 10-fold increase in pituitary prolactin content, a slight growth of the mammary duct system and no milk secretion. 3. When estradiol treatment was followed by a single intravenous injection of reserpine (above dose) and the rabbits killed 1 week later, pituitary prolactin content was at least 16 times greater than in controls. This was accompanied by a considerable degree of lobule-alveolar development and a limited amount of milk secretion in all 6 animals.