Effects of DES on the morphology of the lobes of the baboon prostate.

Ultrastructural examination of the baboon prostate has revealed differences between the caudal and cranial lobes. The cranial epithelium is characterized by electron dense, tall columnar cells which contain numerous secretory vacuoles of homogenous appearance; the caudal epithelium is comparatively shorter in height and lighter in electron opacity. The caudal cells also contain numerous secretory granules which vary in their characteristics. After diethylstilbestrol (DES) treatment (5 mg per day for 3 weeks), the tall caudal cells were reduced to a cuboidal shape; the number of secretory granules in these cells was also markedly reduced. In the cranial lobe, cell height was only moderately reduced, but the secretory vacuoles were decreased both in size and number. In addition, the fibromuscular stroma of the cranial lobe was greatly expanded after DES treatment, with an increased distance between adjoining acini being clearly noted. The systemic effects of DES on the baboons were noted by significantly (P greater than 0.02) elevated levels of serum six hormone binding globulin and significantly reduced serum testosterone levels (P less than 0.01).