A scanning and light microscope study comparing the effects of clomiphene citrate, estradiol 17-beta and progesterone on the structure of uterine luminal epithelial cells

Scanning electron microscopy was used to evaluate the surface ultrastructure of uterine luminal epithelial cells from ovariectomized rats treated with either, high or low doses of Clomiphene citrate or estradiol-17 beta or progesterone given on consecutive days. Light microscopy was used to evaluate the surface epithelium and morphometric methods were used to measure cell height. It was found that clomiphene treatment produced ultrastructural surface features some of which were similar to those seen with hormone treatments and others unique to clomiphene alone. Features reminiscent of oestrogen treatment include hyperplasia and hypertrophy of the luminal epithelium, an increase in the length and density of microvilli and the formation of gland "hillocks". Features reminiscent of progesterone treatment include the development of pinopods and secretion droplets. Features unique to clomiphene treatment include possible stratification of the luminal epithelium, the presence of surface lesions, irregular and doughnut shaped cells, areas of microvilli free plasma membrane and an increase in cell height when compared to the effects of oestrogen and progesterone. It is clear that the effects of clomiphene are both dose and duration dependent; and that some of the morphological features elicited with clomiphene treatment are similar to those seen with the hormone treatments. Overall clomiphene induced features are different to those elicited with either of the hormone treatments tested.