THE EFFECT OF CORTISOL ACETATE ON OESTRONE-INDUCED MAMMARY GLAND GROWTH IN IMMATURE OVARIECTOMIZED ALBINO MICE

Abstract

SUMMARY The response of the mammary glands of ovariectomized albino mice to treatment with 0·003 or 0·006 μg oestrone daily could be distinguished after 21 days of treatment. Differences in mammary gland areas of oestrone-treated ovariectomized mice, and of both ovariectomized and intact controls, were significant. When injected at a level of 12·5 μg daily for 21 days, cortisol acetate (CA) stimulated mammary development in ovariectomized and ovariectomized oestrone-treated albino mice, both growth in area and increase in the number of duct junctions being affected. At higher dosage rates (25 and 50 μg daily) CA was without detectable influence on the mammary glands. The effect of the two steroids upon the mammary glands appeared to be simply additive when analysed on the transformed (logarithmic) scale. The estimate of the density of duct branching—number of duct junctions per unit area—of the mammary glands was not significantly affected by either steroid. Differences in this estimate of mammary gland structure were in general inversely related to differences in area or number of duct junctions. The effects of treatment with CA and with oestrone upon the body weight, adrenal and thymus gland weight, uterine weight and vaginal changes were also observed.