Matsuoka Kanako, Kimura Shingo, Kamijo Tadanobu, Armstrong Lily, Ramezanpour Mehdi, McMahon Brenda, Daugherty Stephanie L, Robertson Anne M, Watton Paul N, Kim Kang, Kojima Yoshiyuki, Yoshimura Naoki
Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA.
Department of Bioengineering, University of Pittsburgh School of Engineering, Pittsburgh, PA, USA.
Int Urol Nephrol. 2025 Aug 25. doi: 10.1007/s11255-025-04746-1.
This study aimed to characterize the time-dependent changes in lower urinary tract function in a rat model of partial bladder outlet obstruction (BOO) using noninvasive techniques, including uroflowmetry and ultrasound imaging.
Eight-week-old male rats underwent partial ligation of the urethra to induce BOO. Voiding behavior was assessed preoperatively and at 1, 2, and 4 weeks postoperatively using metabolic cages. Urine flow rate was calculated based on changes in voided volume over time. Average flow rate, maximum flow rate, and voiding time were derived from these metabolic cage data. Bladder capacity and wall thickness were evaluated by high-resolution ultrasonography.
Voiding frequency significantly increased at 1, 2, and 4 weeks compared to preoperative values. Mean voided volume per micturition was significantly reduced at 2 weeks. Urinary flow curves showed a sawtooth-like pattern, suggestive of external urethral sphincter bursting that is a characteristic of rat voiding. The maximum flow rate significantly decreased at 1 week postoperatively and remained reduced through 4 weeks. Mean flow rate was significantly decreased at 2 weeks, while voiding time showed a tendency to increase, although the difference was not statistically significant. Ultrasonography revealed significant increases in maximum bladder volume at 2 and 4 weeks and in anterior bladder wall thickness at 4 weeks.
This study demonstrated the feasibility of noninvasively monitoring time-dependent changes in rats with BOO. These findings could be extrapolated to the pathophysiological process during the bladder compensation phase in human BOO.
本研究旨在利用包括尿流率测定和超声成像在内的非侵入性技术，描述部分膀胱出口梗阻（BOO）大鼠模型下尿路功能随时间的变化。
8周龄雄性大鼠接受尿道部分结扎以诱导BOO。术前及术后1、2和4周使用代谢笼评估排尿行为。根据排尿量随时间的变化计算尿流率。平均流率、最大流率和排尿时间由这些代谢笼数据得出。通过高分辨率超声评估膀胱容量和壁厚度。
与术前值相比，排尿频率在术后1、2和4周显著增加。每次排尿的平均排尿量在2周时显著减少。尿流曲线呈锯齿状，提示外尿道括约肌突发，这是大鼠排尿的一个特征。最大流率在术后1周显著降低，并在4周内持续降低。平均流率在2周时显著降低，而排尿时间有增加趋势，尽管差异无统计学意义。超声检查显示，在2周和4周时最大膀胱容量显著增加，在4周时膀胱前壁厚度显著增加。
本研究证明了非侵入性监测BOO大鼠随时间变化的可行性。这些发现可外推至人类BOO膀胱代偿期的病理生理过程。
