Estrogen Action: Induction of the Synthesis of a Specific Protein (IP) in the Myometrium, the Stroma and the Luminal Epithelium of the Rat Uterus

Abstract

The effect of estrogen on the synthesis of a specific uterine protein (estrogen-induced protein=IP) was investigated at the level of the epithelial, stromal and myometrial tissue fractions. For measuring IP induction, the procedure of Katzenellenbogen and Gorski was followed exactly (involving co-electrophoresis of soluble protein extracts from 3H-labeled estrogen treated uteri and 14C-labeled controls) except for the fact that the uteri were fractionated into their three main tissue components before homogenization. The results show that induction of IP synthesis by estradiol takes place in the three tissue fractions considered. This is consistent with hypotheses assuming a key function for IP in the development of the full estrogenic response in the uterus.