The ultrastructure of the accessory sex organs of the male rat. XI. Nuclear alterations of prostatic epithelial cells induced by castration.

The fine structure of the nuclei of epithelial cells of the dorsal lobe of the rat prostate were studied 2, 3, 5, 7 and 21 days after castration. The nucleolus appears to undergo a progressive disorganisation with partial fragmentation and dispersion of its normal components. Changes in the nucleoplasm were primarily reflected by a condensation of chromatin, particularly along the nuclear membrane and adjacent to the nucleolus. Later, different types of intranuclear inclusions were observed. After 21 days, the nuclei were characterized by an irregular outline with large indentation. Within the nucleoplasm aggregates of coarse granular chromatin were found. No cell necrosis was observed, indicating that androgen deprivation results in a remodeling of the cell to a less active state with marked cellular alterations and cessation of secretion, but apparently with some of their basic functions still intact. Injections of testosterone completely reverse the castrated-induced alterations. The changes observed are assumed to be due to the withdrawal of the androgenic stimulus, with a direct influence on the secretory function of the cell. The findings support the view that the stimulating secretory effect of androgen is mediated via an intranuclear androgen receptor, probably located in the nucleolus-associated-chromatin. It is also proposed that the secretory function of the epithelial cells of the prostatic complex, initiated by androgens, may be regulated by an intranuclear secretory center.