OBJECTIVE: To determine the effect of tamsulosin hydrochloride on blood flow in the submucosal capillaries of the bladder (SCB) in a rat model of bladder outlet obstruction (BOO) using a pencil lens charge-coupled device microscopy system. MATERIALS AND METHODS: BOO was established in rats by partial ligature of the proximal urethra and was maintained for 2 weeks. Tamsulosin or saline (control) was subcutaneously administered using an osmotic pump for 2 weeks immediately after surgery. The pencil lens charge-coupled device microscopy system was used to visualize the bladder microcirculation and quantitatively assess the blood flow in the SCB by measuring the velocity of the blood flow at the base and dome of the bladder. The blood flow in the SCB of the sham-operated rats, control BOO rats, and tamsulosin-treated BOO rats was compared. RESULTS: The blood flow in the SCB was significantly greater at the base than at the dome of the bladder. The reduction in blood flow through the SCB at the base and dome of the bladder was more significant in the BOO rats than in the sham-operated rats. However, after pretreatment with tamsulosin, the BOO rats showed a significant increase in blood flow through the SCB at the base and dome of the bladder compared with that of the control rats. The pencil lens charge-coupled device microscopy system image showed that the BOO rats had chronic ischemic capillary injury, which was ameliorated by tamsulosin. CONCLUSION: The results of the present study suggest that tamsulosin hydrochloride protects the SCB from ischemic injury after BOO.
OBJECTIVE: To determine the effect of tamsulosin hydrochloride on blood flow in the submucosal capillaries of the bladder (SCB) in a rat model of bladder outlet obstruction (BOO) using a pencil lens charge-coupled device microscopy system. MATERIALS AND METHODS: BOO was established in rats by partial ligature of the proximal urethra and was maintained for 2 weeks. Tamsulosin or saline (control) was subcutaneously administered using an osmotic pump for 2 weeks immediately after surgery. The pencil lens charge-coupled device microscopy system was used to visualize the bladder microcirculation and quantitatively assess the blood flow in the SCB by measuring the velocity of the blood flow at the base and dome of the bladder. The blood flow in the SCB of the sham-operated rats, control BOO rats, and tamsulosin-treated BOO rats was compared. RESULTS: The blood flow in the SCB was significantly greater at the base than at the dome of the bladder. The reduction in blood flow through the SCB at the base and dome of the bladder was more significant in the BOO rats than in the sham-operated rats. However, after pretreatment with tamsulosin, the BOO rats showed a significant increase in blood flow through the SCB at the base and dome of the bladder compared with that of the control rats. The pencil lens charge-coupled device microscopy system image showed that the BOO rats had chronic ischemic capillary injury, which was ameliorated by tamsulosin. CONCLUSION: The results of the present study suggest that tamsulosin hydrochloride protects the SCB from ischemic injury after BOO.