Dose-Response Relationships between Exogenous Progesterone and Estradiol and Porcine Uterine Protein Secretions

Abstract

Effects of varying amounts and/or ratios of progesterone and/or estradiol on quantitative changes in porcine uterine protein secretions in ovariectomized and sham-operated gilts were examined in three experiments. The first experiment evaluated effects of administering varying quantities of progesterone and estradiol at a constant ratio of 2000:1 (P:E); the second determined effects of varying the quantity of progesterone while maintaining a constant quantity of estradiol; and the third, effects of injecting progesterone alone. Quantity of recoverable uterine protein secretion at day 15 of the estrous cycle, following ovariectomy or sham-operation on day 4 after onset of estrus and daily hormone therapy until day 15, was the treatment response measured in all three experiments. In general, quantity of total recoverable uterine protein increased as the quantity of exogenous progesterone administered increased. This increase was more apparent in ovariectomized gilts than it was in intact, sham-operated gilts. This apparently was due to reduction or elimination of endogenous progesterone and estrogen and thus the elimination of their possible influence on the quantity of recoverable uterine protein. Copyright © 1974. American Society of Animal Science . Copyright 1974 by American Society of Animal Science.