STUDIES ON THE UTERINE GROWTH-STIMULATING EFFECTS OF COMBINATIONS OF TESTOSTERONE PROPIONATE AND NATURAL OESTROGENS

Abstract

Testosterone propionate (TP), at a high dose level, produces an increase in the uterine growth produced by oestrone, 17[beta]-oestradiol or oestriol, also at high dose levels. When low doses of TP were added to relatively high doses of the oestrogens, they were found to be additive with oestriol, inactive with 17[beta]-oestradiol and inhibitory only with oestrone. Although in the conditions of this test the major type of interaction between oestrogens and androgens is additive, an inhibitory component is sometimes present. This is in contrast to the findings of Velardo and our own mouse uterine growth studies in which inhibition was most obvious. This additive-inhibitory pattern of activities appears characteristic for mixtures of oestrogens and other steroids, which suggests a sort of buffering on the biological level.