We examined the effect of androgens on bladder blood flow (BBF), bladder function and histological changes in castrated male rats. Male Wistar rats were classified into unoperated group (control group), groups castrated at the age of 8 weeks (group 8wPC) and groups castrated at the age of 4 weeks (group 4wPC). Each rat was used at the age of 20 weeks. BBF was measured using fluorescent microspheres. Bladder cystometry was performed without anesthesia or restraint; the bladder was first irrigated with saline and then with 0.25% acetic acid (AA) solution. Maximum voiding pressure and voiding interval were measured. The bladder and iliac artery were histologically examined for differences in smooth muscle and quantity of collagen fiber to analyze the effect of castration on the smooth muscle content. No differences were noted in BBF following castration. The voiding intervals for all groups were shortened (P < 0.001) following AA irrigation. No significant difference was noted in the maximum voiding pressure. Histological changes were observed in bladder and iliac artery. Smooth muscle/collagen ratio at the bladder was lower in groups 8wPC and 4wPC compared to the control group (P< 0.01), while that at the iliac artery was decreased in group 4wPC compared to the control group (P< 0.001). In conclusion, our findings indicate that castration does not alter BBF, but leads to histological changes in the bladder as well as its associated blood vessels.

Consideration of detailed medical history, enforcement of UDS, and closer cooperation between urologists and neurologists are required to ascertain early and correct diagnosis, and to avoid unnecessary surgery.

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During the acute phase of androgen deprivation following castration, BBF significantly increased and the bladder became receptive to stimulation. This temporary increase may be because of a decrease in the prostate blood flow, indicating that androgens do not directly affect the BBF.