Temporal effects of estradiol on progesterone receptor and glycoprotein synthesis in the epithelial-stromal complex of the rabbit endocervix.

The temporal effects of a single injection of estradiol (5 micrograms in corn oil) were studied in 18- to 23-week ovariectomized rabbits for up to 48 h. Changes in cytosol and nuclear progesterone receptor concentrations in the epithelial-stromal complex were correlated with ultrastructural evidence of glycoprotein synthesis by nonciliated epithelial cells. After exposure to estradiol for 12 h, the Golgi cisternae of a few of the nonciliated cells contained secretory granules. After 24 h exposure, the number of nonciliated cells containing secretory granules was increased as was the number of granules per cell. After 36 h exposure, both the intracellular complement of secretory granules and the concentration of cytosol progesterone receptor (15.1 +/- 2.7 pmol/mg DNA) had reached a maximum. The concentration of cytosol progesterone receptor had increased 2-fold over the concentration (7.8 +/- 0.8 pmol/mg DNA) for ovariectomized rabbits. The concentration of nuclear progesterone receptor had increased from 66.3 +/- 26.3 fmol/mg DNA to 1459.5 +/- 99.3 fmol/mg DNA. After 48 h exposure the cellular complement of secretory granules was reduced as was the concentration of cytosol (5.0 +/- 0.5 pmol/mg DNA) and nuclear (740.0 +/- 364.9 fmol/mg DNA) progesterone receptor. It is apparent that the production of secretory granules and progesterone receptor concentration are temporally dependent upon estradiol.