Improved model for the establishment and evaluation of detrusor overactivity in female Wistar rats

Objective To improve the model for establishment and evaluation of detrusor overactivity in female Wistar rats. Materials and Methods We ligated the perineal urethra of female Wistar rats and then performed filling cystometry. The probability of detrusor overactivity, bladder capacity, peak voiding pressure and histological changes were investigated. Results Detrusor overactivity ratio of the obstruction group was 32.4%. Bladder capacity increased from 0.273 ± 0.036mL in control group to 0.89 ± 0.19mL in detrusor overactivity group (P < 0.001), and peak voiding pressure increased from 45.9 ± 4.1 cm.H2O to 63.5 ± 17.4cm.H2O (P = 0.007). For obstruction group, compared to no detrusor overactivity rats, detrusor overactivity rats had higher bladder capacity (0.89 ± 0.19mL versus 0.43 ± 0.09mL, P < 0.001) and higher peak voiding pressure (63.5 ± 17.4cm.H2O versus 44.8 ± 6.2cm.H2O, P = 0.005). Detrusor overactivity rats were classified according to peak voiding pressure (49.2 ± 4.2cm.H2O versus 80.8 ± 7.1cm.H2O, P < 0.001). Moreover, bladder weight increased significantly in detrusor overactivity rats (P = 0.003, P = 0.028) and detrusor histological hypertrophy was observed. Conclusions Ligating perineal urethra and filling cystometry with intra-urethral cannula approach is a simple and easily reproducible method to establish and evaluate the model of detrusor overactivity in rats.

研究目的：优化雌性Wistar大鼠逼尿肌过度活动模型的构建与评价方法。
材料与方法：本研究对雌性Wistar大鼠行会阴尿道结扎术，随后开展充盈性膀胱测压。本次实验检测指标包括逼尿肌过度活动发生率、膀胱容量、排尿峰压及组织病理学变化。
结果：梗阻组逼尿肌过度活动发生率为32.4%。对照组膀胱容量为0.273±0.036mL，逼尿肌过度活动组膀胱容量升至0.89±0.19mL（P<0.001）；排尿峰压从45.9±4.1cmH₂O升高至63.5±17.4cmH₂O（P=0.007）。在梗阻组中，与未发生逼尿肌过度活动的大鼠相比，发生逼尿肌过度活动的大鼠膀胱容量更高（0.89±0.19mL vs 0.43±0.09mL，P<0.001），排尿峰压亦更高（63.5±17.4cmH₂O vs 44.8±6.2cmH₂O，P=0.005）。按排尿峰压对逼尿肌过度活动大鼠进行分组时，两组的排尿峰压分别为49.2±4.2cmH₂O与80.8±7.1cmH₂O（P<0.001）。此外，逼尿肌过度活动大鼠的膀胱重量显著升高（P=0.003、P=0.028），且可见逼尿肌组织肥大的病理表现。
结论：采用会阴尿道结扎联合尿道内置管行充盈性膀胱测压的方法，可简便且重复性佳地构建并评价大鼠逼尿肌过度活动模型。