Ultrastructural changes in subepithelial capillaries and their surrounding stroma in rat prostate and seminal vesicle after castration.

The purpose of this study was to clarify the androgen-ablation-induced morphological changes in the capillaries and stroma near the epithelial cells in prostate and seminal vesicles (SV) using transmission electron microscopy (TEM). In ventral prostate (VP) and SV of immature male rats, the luminal areas of subepithelial capillaries and the width of the stromal layers between endothelia and epithelia were measured quantitatively after castration using TEM and a computed image analyzer. The luminal areas of the capillaries were significantly reduced in VP and SV in the short-term after castration. In the stromal layer, the width of the collagen layer surrounding the capillary significantly increased in VP and SV in the long-term after castration. These data suggest that the reduction of the capillaries and the thickening of collagen surrounding them are related to the involution of glandular epithelial cells in VP and SV after castration.