Stimulation of Abnormal Mammary Growth by Large Amounts of Estrogenic Hormone

Purified estrogenic hormones (theelin and theelol)∗ induced a growth of the mammary duct system (Turner, et al. 1 ) Theelin stimulated a growth of the mammary duct system of male mice (Turner and Gomez 2 ; Gardner, Diddle, Allen, and Strong 3 ). The extent and type of development were comparable with that observed in mature virgin female mice or male mice bearing ovarian grafts (Gardner 4 ).

The water soluble hormone (theelin) in daily doses of 1 to 5 rat units administered subcutaneously in 2 injections induced a localized excessive development of lobules of alveoli along the mammary ducts of male mice of one strain (C₃H). A high percentage of females of this strain developed mammary cancer. Similar lobules of alveoli have been found in the mammary glands of male mice from one other cancer susceptible and one cancer resistant strain when theelin had been administered for periods of several months.

The present observations were made on male mice from 2 cancer susceptible strains (A and C₃H), which were given weekly injections of 500 international units of folliculin benzoate† in oil. The mice were from 3 to 28 days old when placed on experiment. They were removed at periods varying from 101 to 172 days. The total amounts of folliculin benzoate varied from 7,500 to 12,500 units. The 6 mice that were 28 days old developed scrotal hernias after 6 to 8 weeks of treatment. Hydronephrosis and other conditions developed at a later date resulting in a rapid emaciation.