Stress urinary incontinence following vaginal trauma involves remodeling of urethral connective tissue in female mice.

Abstract

OBJECTIVE: The molecular mechanisms underlying stress urinary incontinence (SUI) are not clear. This study was conducted to evaluate molecular alterations in the urethras of mice with experimentally induced SUI. STUDY DESIGN: Eighteen virgin female mice were equally distributed into three groups as follows: two groups undergoing vaginal distension (VD) for 1 h with 3 mm and 8 mm dilators each, and a non-instrumented control group. Changes in leak point pressure (LPP), morphology, lysyl oxidase (LOX) expression and the metabolism of urethral connective tissue were assessed. RESULTS: The LPP was significantly decreased in the 3 mm and 8 mm VD groups compared with that in the control group. Collagen and elastin expression in the urethra was significantly decreased in the 8 mm VD group compared with that in the control group, while LOX expression was significantly enhanced. CONCLUSIONS: SUI following vaginal trauma involves over-expression of LOX and decreased synthesis of extracellular matrix components or increased proteolysis in the urethra.