Effect of progesterone treatment on the uptake of estradiol-17 beta by uterine tissues of ovariectomised rats

Effects of progesterone on uptake and metabolism of 17 beta-estradiol by mouse uterine luminal epithelium

The influence of progesterone (P4) pretreatment on the uptake and retention of [3H]estradiol-17 beta ([3H]E2) in whole uterus and luminal epithelium was examined in ovariectomized mice. After s.c. injection of 50 ng [3H]E2 uterine, epithelial and epithelial nuclear levels of radioactivity were maximal 3 h post-injection: maximum epithelial levels were sustained from 3 to 6 h in Pa-treated, but not control tissue. P4 treatment did not significantly alter the proportion of epithelial or uterine radioactivity recovered as [3H]E2, or the intracellular distribution of the hormone. Preparation of epithelial suspensions in buffer containing excess 17 beta-estradiol (E2) did not significantly alter their [3H]E2 content. After intraluminal injection of 100 pg [3H]E2 rates of loss from uterine, epithelial and epithelial nuclear preparations did not differ significantly between control and P4-treated tissues. We conclude that P4 does not inhibit E2-induced luminal epithelial mitosis by preventing E2 reaching the epithelial cells and nuclei, by changing its distribution in the tissue, or by increasing its rate of loss from the tissue or its metabolism to less active estrogens like estrone.

Nuclear progesterone and estradiol receptors in deciduomata induced in ovariectomised rats

The levels of nuclear progesterone and estradiol receptors have been followed during the development and decline of deciduomata induced in the uteri of ovariectomised rats. There were broadly 2 phases of deciduomal growth, the first phase being associated with high estrogen nuclear receptor levels per unit DNA. Progesterone nuclear receptor levels did not greatly change (in relation to DNA content) during both phases of full deciduomal development but peak levels were observed on day 5 after decidualization. Alkaline phosphatase activity was maximal by day 3, before peak hormone receptor levels were reached in the nuclei.

Effect of methanabol (17 beta hydroxy-17 alpha methyl-1,4-androstadiene-3-one) on growth and breast muscle nucleic acid content in the chicken

1. The effect of methanabol (17 beta hydroxy-17 alpha methyl-1,4-androstadiene-3-one) on growth and breast muscle nucleic acid in White Rock chickens grown to 8 weeks of age was tested. Methanabol was administered by mouth daily during this period at 0.05 mg/kg body weight in aqueous suspension to 30 birds, with appropriate controls. 2. Growth was significantly increased by methanabol. 3. Breast muscle RNA was significantly increased by methanabol but DNA was not affected.