Successful induction of stress urinary incontinence in mice by vaginal distension does not depend on the estrous cycle

摘要

Objective To determine if the performance of vaginal distension (VD) in different estrous cycle phases affects the successful induction of stress urinary incontinence in mice. Methods Female virgin C57BL/6 mice were distributed into 4 groups according to their estrous cycle phase: proestrus, estrus, metestrus, or diestrus. The estrous cycle was staged by examining vaginal smears, and the method was corroborated by histologic examination of the vagina in a subset of each group. Each group was divided into 4 subgroups for measurement of 24-hour micturition behavior and the leak point pressure (LPP) 4 or 20 days after VD or sham VD. Results Voiding events increased and mean void volume decreased 4 days, but not 20 days after VD, and the LPP was decreased 4 days, but not 20 days after VD compared with the corresponding sham group, regardless of the estrous cycle phase when VD was performed. There were no differences in 24-hour micturition behavior or LPP among the 4 different estrous cycle phases either in sham or VD group. Conclusion Successful induction of reversible stress urinary incontinence in mice is not dependent on the estrous cycle.