Effect of Stilbestrol on the Mammary Gland of the Mouse, Rat, Rabbit, and Goat

Abstract

Summary Subcutaneous injections of stilbestrol at low dosages caused extensive duct proliferation in male mice in 2 to 4 weeks. Mammary development did not proceed farther in spayed virgin female mice similarly treated. Oral administration of stilbestrol to male mice required approximately six times as high a dosage as by injection to obtain similar results. Castrate male rats required a higher dosage of stilbestrol than did mice to obtain mammary duct growth. Four-tenths gamma per day of stilbestrol subcutaneously was adequate to secure extensive mammary duct development in male rabbits. After 40 to 60 days treatment early lobule development was apparent. Percutaneous administration was also effective. Mammary glands from two rabbits with subcutaneous pellets had well developed lobule-alveolar systems and responded well to lactogen treatment at 90 days. Normal females tended to lactate on stilbestrol injection alone. Subcutaneous injection of stilbestrol into virgin goats caused abundant and prolonged lactation from lobule-alveolar glands. Little increase in extent of glands was apparent. Subcutaneous administration followed by pellet implantation caused no mammary gland development in a castrate male goat, although the teats were hypertrophied.