Changes in detrusor and urinary growth factors according to detrusor function after partial bladder outlet obstruction in the rat

Objectives. To investigate the changes in detrusor and urinary growth factors according to detrusor function after partial bladder outlet obstruction in the rat. Growth factors have been reported to play a role in the remodeling of the bladder after obstruction. Methods. Female rats (n = 40) were used and divided into three groups: sham-operated control, 2-week mild obstruction, and 2-week severe obstruction. The voided urine was collected and the detrusor contractility to electrical stimulation recorded. mRNA expression and the urinary concentration of transforming growth factor beta-1 (TGF-β1) and basic fibroblast growth factor (bFGF) were analyzed. Results. The contractile response to electrical stimulation was increased in the mild obstruction group (P <0.05) but decreased in the severe obstruction group (P <0.05). The detrusor mRNA expression of TGF-β1 in the mild obstruction group was not different from that in the control group. However, in the severe obstruction group, the mRNA expression of TGF-β1 increased. The detrusor mRNA expression of bFGF was gradually increased in the mild and severe obstruction groups. The urinary concentration of TGF-β1 in the mild obstruction group was not significantly different from that in the control group. However, in the severe obstruction group, the concentration of TGF-β1 was significantly increased (P <0.05). The concentration of urinary bFGF was too small to compare the results in each group. Conclusions. Growth factors such as TGF-β1 and bFGF change in mRNA expression according to bladder function, and urinary TGF-β1 reflects the change of detrusor mRNA. Thus, changes in TGF-β1 may be a marker to evaluate detrusor function.