Ultrastructural study in canine prostatic hyperplasia--effect of antiandrogen

Ultrastructural changes in canine prostates after treatment with chlormadinone acetate (CMA) were investigated. Old male beagle dogs (5-8 years old ) were divided into two experimental groups; group 1 consisted of benign prostatic hyperplasia (BPH) controls, and group 2 received 0.3 mg/kg/day CMA orally for 6 months. In group 1 animals, the most striking ultrastructural changes were detected in the rough endoplasmic reticulum (rER) and Golgi complexes. The secretory granules were lined up along the apical plasma membrane, and exocytosis was frequently seen. In group 2 animals, the cytoplasm was electron-lucent and contained relatively few, poorly developed organelles. The rER was sparse and consisted of a few scattered, short profiles studded with ribosomes. The Golgi complexes were inconspicuous. The secretory granules were markedly decreased in both number and size. Furthermore, mitochondrial degeneration such as swollen or disappeared mitochondrial cristae or decreased electron density of the matrix were frequently seen in the smooth muscle cells. Based on our data, atrophy after treatment with CMA may be due to shrinkage of both glandular and stromal compartments in the prostate tissue.