The effect of cestrone on mice of three inbred strains, with special reference to the mammary glands

Abstract

Over 300 mice belonging to 3 inbred strains differing in their incidence of spontaneous mammary carcinoma 135 Simpson 75 Edinburgh and 112 CBA mice were used for this study. The mice were divided into 4 groups ovariectomized and nonovariectomized females and castrated and noncastrated males and administered weekly with subcutaneous injection of 300 international units of estrone from 5 weeks to death. Estrone treatment produced 44 palpable mammary tumors in the Simpson mice 3 tumors in the Edinburgh mice and none in the CBA mice although these had the longest life-span and therefore received the greatest amount of estrone. Ovariectomized females responded more slowly and to a lesser degree than nonovariectomized females thus showing that ovariectomy prolonged life. Castrated males responded more rapidly and to a greater degree than noncastrated males thus showing that castration shortened life. In other words while the presence of the naturally occurring female hormone increased the effect of treatment the action of the male hormone appeared to be antagonistic to that of estrone. Estrone treatment produced 30 uterine tumors mainly cervical fibromata and fibrosarcomata in 54 CBA females 4 cervical tumors in the Edinburgh and 2 in the Simpson strains. Estrone administration did not affect the incidence of lung tumor but it increased the incidence of lymphadenopathies.