Expression of Aquaporins in Prostate and Seminal Vesicles of Diabetic Rats

Aquaporins (AQPs) are membrane proteins that facilitate the movement of water and many small solutes across biological membranes. Seminal fluid is primarily produced by prostate and seminal vesicles, and its production may potentially be mediated by many mechanisms related to transudation of fluid. Epidemiological data suggest that semen volume in diabetic men is significantly less than in nondiabetic men.To investigate the change in volume of secretions of the prostate and seminal vesicles in diabetic rats and its association with the expression of AQPs 1-4.Twenty male Sprague Dawley rats were randomly divided among 4- and 6-week diabetic groups and 4- and 6-week control groups. Prostate and seminal vesicle secretions were collected and measured, and levels of expression of AQPs 1-4 were determined by immunohistochemical study and Western blot.The levels of expression of AQPs 1-4 were determined in the prostate and seminal vesicles of diabetic rats by Western blot and immunohistochemical study.Plasma glucose was significantly higher in diabetic model groups than in controls (P < 0.05). The weights of secretions of the prostate and seminal vesicles were significantly lower in diabetic model groups (P < 0.05). The levels of expression of AQPs 1 and 4 in seminal vesicles were significantly lower in diabetic model groups (P < 0.05). There was no difference in the level of expression of AQP3 in seminal vesicles among the groups. The levels of expression of AQPs 1, 3, and 4 in prostate were significantly lower in diabetic model groups (P < 0.05). AQP2 was not detectable in the prostate or seminal vesicles of any of the groups.Decreased weight of prostate secretions in diabetic rats may be partly due to decreased levels of AQPs 1, 3, and 4 in prostatic tissue. Decreased weight of seminal vesicle secretions in diabetic rats may be partly due to decreased levels of AQP1 and AQP4 in seminal vesicles. There is no relationship between the expression of AQPs 1-4 and the duration of disease.