Research on a rat model of female stress urinary incontinence / 中华老年医学杂志

ABSTRACT

Objective To investigate the pathological changes and mechanism in the urethra by parturition-induced stress urinary incontinence.Methods Sprague Dawley female rats underwent vaginal balloon dilation for 4 hours immediately after delivery.One week later,the rats were anesthetized and both ovaries were excised.Then a rat model of stress urinary incontinence (SUI) was successfully established.One month after ovariectomy,conscious cystometry and Leak-Point Pressure (LPP) were measured by MP150.Histological examination and Western blotting were performed after functional assays.Results (1) 85％ of rats presented astress urinary incontinence in the model group.(2) The urethras in SUI rats had decreased muscles,and striated muscles showed fragmentized and disorganized.(3) Elastic fibers were long,well organized and tightly connected to the muscle bundles in sham group,while elastic fibers showed fragmentation and disorganization in the model group.(4) The protein expression of vascular endothelial growth factor (VEGF) and blood vessels were reduced in SUI rats as compared with the sham rats.Conclusions Muscle and elastic fibers in the urethra are disrupted in SUI rat.VEGF may play an important role in regulation of pathological changes in urethra.