Morphological and immunohistochemical comparison of three rat prostate lobes (lateral, dorsal and ventral) in experimental hyperprolactinemia.

The prolactin plays an important role in the regulation of growth and differentiation of prostate gland besides androgens. The goal of this study was to reveal the influence of elevated prolactin concentration on epithelial cells of prostate. We compared the morphology of epithelial cells of prostate dorsal, lateral and ventral lobes and expression of androgen receptors in these cells in rats with hyperprolactinemia and in control rats. We used sexually mature male Wistar rats. The experimental rats received metoclopramide; the control group received saline in the same way. The prostate dorsal, lateral and ventral lobes were collected routinely for light and electron microscopy. The intensity of immunohistochemical reaction of androgen receptor in epithelial cells of dorsal, lateral and ventral lobes was evaluated by measure of optical density with computer image analysis. The light and electron (transmission and scanning) microscopes were used for morphological observations. Results: In experimental rats twofold increase in prolactin and twofold decrease in testosterone found. In experimental group the expression of androgen receptor was lower in columnar epithelial cells of dorsal and ventral lobes but higher in lateral one. We observed morphological abnormalities in columnar epithelial cells of lateral and dorsal lobes. The columnar epithelial cells of ventral lobes didn't show any morphological changes in hyperprolactinemia