Urodynamic characteristics of rats with detrusor instability

The purpose of the present study is to investigate urodynamic characteristics of rats with detrusor instability (DI) induced by different causes. Forty-eight adult female Sprague-Dawly rats were randomly divided into 4 groups: cyclophosphamide group, bladder outlet obstruction group, lipopolysaccharide group and control group. The BL-410 model bio-function experimental system was applied to monitor bladder pressure and a number of urodynamic parameters were recorded and calculated, including the frequency of detrusor instability, maximum voiding pressure (MVP), maximum cystometric capacity (MCC), intercontraction interval (ICI), voiding time (VT), postvoid residual (PVR) and bladder compliance (BC). The positive rates of DI in cyclophosphamide group, bladder outlet obstruction group and lipopolysaccharide group were 83.33%, 75.00% and 58.33%, respectively. And correspondingly the frequency of DI was 10.00±2.00, 4.87±1.24 and 3.50±1.00tmin(-1), which was significantly higher than those of the control group (P<0.05). Compared with the control group, the decrease of MVP, MCC, ICI, VT and BC was noted in the cyclophosphamide group and lipopolysaccharide group. Increased PVR, MVP, MCC, VT and BC were presented in the bladder outlet obstruction group. Therefore, we suggested that the urodynamic parameters could reflect the pathophysiological characteristics of DI induced by different causes, which could systematically benefit the diagnosis and treatment of overactive bladder.