Effect of Bladder Outlet Obstruction on Blood Flow and Tissue Collagen in Rat Bladder

Oh, Sang Hyun; Min, Kyung Dae; Kwon, Dong Deuk; Park, Yang Il

Abstract

Partial bladder outlet obstruction is one of the major urological complication induced by benign prostatic hypertrophy (BPH). The current study describes the effect of partial bladder outlet obstruction on detrusor blood flow, bladder weight and tissue collagen in rat. We divided 30 female Sprague-Dawley rats weighing 250-300g into three group: sham-operated control rats, rats with partial outlet obstruction for 2-weeks, and rats with 4-weeks partial outlet obstruction. Detrusor layer blood flow were measured using radiolabelled microsphere techniques in three groups. The effect of chronic bladder outlet obstruction on bladder weight and bladder tissue collagen was also described. The weight of the bladder was significantly increased in both 2-weeks and 4-weeks partial obstruction group. The 4-weeks obstruction group exhibited a greater increase in weight. Bladder detrusor layer blood flow decreased significantly in 2-weeks and 4-weeks obstruction group compared with the control group, with no significant difference between 2-weeks and 4-weeks partial obstruction group. Histology of the obstructed bladder specimen revealed hypertrophied muscles and thickened collagen fibers. In the obstructed bladder, blood flow decreased significantly compared with that of control group, but there was no significant difference between 2-weeks obstruction and 4-weeks obstruction group. Bladder weight increased in obstructed bladder and long-time obstructed bladder showed greater increase in weight.