Epididymal cytology changes in hypothyroid rats.

The purpose of this research was to investigate, using light, transmission, and scanning electron microscope, the effect of hypothyroidism on the ultrastructure of the rat epididymis. Thyroidectomy was obtained by ip injection of 270 microCi of (131)I per rat. One month later, several portions of cauda epididymis were examined. Morphological differences were detected in the epididymis of the hypothyroid animals when compared to the control normal rats. The hypothyroid conditions were associated with important changes in the epididymis. The light observations showed cells with clearing of the chromatin and increased density and thickness of the chromatic rim, chromatinic net, and disappearance of the segment of the chromatin rim. In the scanning electron microscope broken, oblique, denuded epithelial cells with loss of stereocilia were observed, as well as flattening of the tubule. The hypothyroid condition under transmission electron microscope was associated with a decrease in the height of the cells, diminution of the internal lumen and number of mitoses, and decreased chromatin decondensation. Results obtained confirmed that hypothyroidism causes marked structural changes in the ductus epididymis and could adversely affect the maturation and motility of sperm.