OBJECTIVETo investigate the levels of secretions from the prostate and seminal vesicles and their association with the expressions of aquaporins (AQP) in the prostatic tissue and seminal vesicles of castrated rats.

METHODSWe randomly divided 18 eight-week-old male SD rats into a control, a castration, and a testosterone (T) replacement group. Four weeks after surgical castration, we detected the plasma T level and measured the volumes of the secretions and the expressions of AQPs 3, 7, and 10 - 12 in the prostate and seminal vesicles of the rats.

RESULTSThe plasma T level was significantly lower in the castrated models ([30. 98 ± 28. 84] ng/dl) than in the rats of the control ([700.78 ± 123.8] ng/dl) and T replacement groups ([688.08 ± 132. 47] ng/dl) (P <0. 05). The castration group, in comparison with the control and T replacement groups, showed remarkably reduced ratios of prostatic secretion volume / prostate weight ([11.1 ± 0.30] vs [2.32 ± 0.61] and [2.13 ± 0.56] %, P <0. 05) and seminal vesicle secretion volume / seminal vesicle weight ( [4. 78 ± 1. 97 ] vs [57. 36 ± 11. 86] and [55. 74 ± 7. 21] %, P < 0. 05). Immunohistochemistry revealed the expressions of AQPs 3 and 7 in the epithelial envelop and cytoplasm and that of AQP 11 the in endothelial envelop and cytoplasm of the prostate and seminal vesicles. Western blot exhibited significantly lower expressions of AQPs 3, 7, and 10 - 12 in the prostate and seminal vesicles of the castrated rats than in the animals of the control and T replacement groups (P <0. 05).

CONCLUSIONSignificant decreases of the secretions from the prostate and seminal vesicles may be related to the reduced expressions of AQPs 3, 7, and 10 - 12 in the prostatic tissue and seminal vesicles in castrated rats.