Kidney tubule cell injury of male rats after estrogen treatment.

Ultrastructural changes in the tubular epithelium of the rat kidney following a large dose of estrogen (300 micrograms per week for 20 weeks) were studied by means of electron microscopy. The ultrastructural changes in estrogen-treated rats were confined to the proximal tubule. The changes consisted of intracytoplasmic vacuoles and dilatation of the intracellular space between adjacent tubule cells. The cisternae of the endoplasmic reticulum exhibited some degree of vesiculation characterized by club-like formations. In addition, large masses of collagen could be observed within the peritubular capillaries. In contrast to the controls the tubular cells of estrogen-treated rats exhibited large areas or granules with dense inclusions and membranous, filamentous material in a process of being transformed into an autolysosome and residual body. The results are discussed in the light of those of other authors.