Short-term effects of androgen withdrawal on the structure of different epithelial cells in the rat epididymis.

Rat spermatozoa are highly dependent on the milieu of the normal epididymis for their maturation and survival, and die within a few days after androgenic support of the epididymal epithelium is withdrawn. The immediate changes in the ultrastructural organization of the epithelial cells of the rat epididymis, 2, 4, 6 and 14 days following castration have been monitored by morphometric analysis of localized regions of the caput and cauda epididymidis. While castration results in greater endocytosis by principal cells (Moore and Bedford, '79), many of their early structural changes following androgen withdrawal (disappearance of vesicles from the cell apex, reduction in rough endoplasmic reticulum, a drop in the volume of the Golgi cisternae and increase in lysosome content) seem indicative of inhibition of a secretory function. By contrast with the regressive response of the principal cell, the ultrastructure of clear cells in the cauda and of apical cells in the caput region appeared unchanged up to 14 days after castration. The implications of this evidence for specialized functions, and the suggestion of a differential androgen dependence among major cell types of the epididymal epithelium, are discussed briefly.