Effects of bladder outlet obstruction on detrusor biomechanical properties / 第三军医大学学报

ABSTRACT

Objective To establish a stable animal model of bladder outlet obstruction(BOO) and to clarify the effects of BOO on the biomechanical properties of detrusor and the mechanisms. Methods BOO animal model was established by partial ligation of the proximal urethra of male Wistar rats forming, a urethra stricture with internal diameter of 1 mm. The active contraction of detrusor muscle stripes to carbachol was recorded with transfusor and organ bath tube. The compliance and maximum volume of bladder were examined by filling cystometry. Results The bladders demonstrated tropical post obstruction alterations at week 2 after partial ligation of the proximal urethra. The maximum volume (3 3?1 9) ml and bladder wet weight (10 4?2 8) g increased significantly in BOO group as compared with those in sham operation group [(1 6?0 8)ml and (7 2?3 5)g]. The detrusor contractile force of detrusor instability(DI) group was significantly lower than that in the control group. However, the contractile force in detrusor stability (DS) group was higher at week 2 but lower at week 4 after BOO than that in the sham operation group. Conclusion BOO animal model established by partial ligation of the proximal urethra of adult rats is simple and can give high survival rate and good stability, suitable for the studies of bladder outlet obstruction. There are two types of the detrusor contraction after BOO: DI group with impaired contraction and DS group with bidirectional change which was higher at early stage(week 2) but lower at later stage(week 4). The changes of bladder compliance are related to the stability of bladder, decrease in DI but increase in DS.