Expression of Neuroendocrine Cells in the Prostate of Rat and Guinea Pig after Orchiectomy

Lee, Jong Jin; Choi, Hong Yong; Lee, Nam Kyu

Abstract

PURPOSE: Neuroendocrine cells, also referred to as amine precursor uptake and decarboxylation (APUD) cells, in the prostate gland are serotonin and peptide containing cells, which are thought to play an important role in the regulation of growth, cellular differentiation and homeostasis. The expressions of neuroendocrine cells in the prostate differ between species and pathological conditions of the prostate. Androgen is believed to be a major effective material toward the prostate, its role in neuroendocrine cells is uncertain. The objective of this study was to investigate the effects of blockade of androgen on neuroendocrine cells in the prostate of rats and guinea pigs.
MATERIALS AND METHODS
Rats and guinea pigs underwent an orchiectomy, and their prostate glands removed at 0 (control), 2 (2-week group) and 6 (6-week group) weeks after the orchiectomy. Each prostate tissue was examined both microscopically and with immunohistochemistry using synaptophysin, chromogranin A and serotonin.
RESULTS
In the rat prostate glands, fewer neuroendocrine cells were stained with chromogranin A compared to the other two monoclonal antibodies. Although some atrophy of the glandular structure was presented grossly and microscopically in the castration groups, there was no difference in the chromogranin A immunoreactivity between the control, 2-week and 6-week groups. In the guinea pig prostate glands, few neuroendocrine cells were stained with either synaptophysin or serotonin. Glandular atrophy presented in the castration groups. There was no difference between the control, 2-week and 6-week groups in the immunoreactivities of the synaptophysin and serotonin monoclonal antibodies.
CONCLUSIONS
The immunoreactivities of the neuroendocrine cells of rats and guinea pigs were different from those in humans and from each other. Neuroendocrine cells in the prostate of rats and guinea pigs exist only in small numbers, and seem to be independent of androgen.