Histoquantitative effects of orchiectomy with and without testosterone enanthate treatment on the bovine epididymis

The histoquantitative effects of orchiectomy with and without testosterone enanthate treatment on the bovine epididymis as relates to epithelial height, luminal diameter, and thickness of smooth muscle wall were determined. With androgen deprivation (induced by orchiectomy), epithelial heights in epididymal regions I, II, III, IV, V, and VI were reduced to 25%, 47%, 46%, 39%, 39%, and 79% of the controls respectively. In the orchiectomized bulls treated with testosterone, the epithelial height in region I increased to only 29% of the controls and the heights reached 58% to 67% of the controls in regions II to V and as much as 111% in region VI. These data indicate that circulating testosterone does not have an important role in maintaining the epithelial height in region I, whereas it seems to be solely responsible for its maintenance in region VI. The epithelial heights in regions, II, III, IV, and V are probably dependent on both circulating and luminal androgens. Similar to the epithelial height, the luminal diameter in all regions was markedly reduced by orchiectomy; however, testosterone treatment failed to restore the diameter to the control levels. In contrast to the epithelial height and luminal diameter, the thickness of the smooth muscle wall in all regions was significantly increased following orchiectomy. Although it decreased in the orchiectomized bulls treated with testosterone, it was still thicker than that of controls. The relative significance of luminal and circulating androgens in maintaining the structure and function of the epididymal epithelium is discussed.