Department of Urology, Research Institute of Medical Sciences, Chonnam National University, 8, Hak-dong, Dong-ku, Gwangju 501-757, Korea.
BMC Urol. 2013 Sep 16;13:44. doi: 10.1186/1471-2490-13-44.
The purpose of this study was to investigate the effect of estrogen alteration on the expression of caveolin 2 and 3 in rat smooth muscle of urinary bladder.
Female Sprague-Dawley rats were divided into three groups: control, bilateral ovariectomy (Ovx), and bilateral ovariectomy followed by subcutaneous injections of 17β-estradiol (Ovx+Est). After 4 weeks, urodynamic measurements were taken to ascertain the contraction interval and contraction pressure. The expression and cellular localization of caveolin 2 and 3 were determined by Western blot and immunohistochemistry in rat urinary bladder smooth muscle.
In cystometrograms, the contraction interval (min) was significantly lower in the Ovx group (3.1±1.5) than in the control group (5.6±1.2), but was increased after estrogen treatment (9.3±1.0). Conversely, the average contraction pressure (mmHg) was higher in the Ovx group (26.2±2.3) than in the control group (21.9±3.1), and was decreased after estrogen treatment (23.8±3.5). Caveolin 2 and 3 expression was localized in the cell membrane of the smooth muscle. The protein expression of both caveolin 2 and 3 was significantly lower after ovariectomy and was restored to the control levels after 17β-estradiol treatment.
Hormonal alteration causes a significant change in the expression of caveolin 2 and 3 in smooth muscle of rat urinary bladder. These findings suggest that these molecules might have functional roles in the detrusor overactivity that occurs in association with hormonal alteration.
本研究旨在探讨雌激素变化对大鼠膀胱平滑肌中窖蛋白 2 和 3 表达的影响。
将雌性 Sprague-Dawley 大鼠分为三组：对照组、双侧卵巢切除术（Ovx）组和双侧卵巢切除术后皮下注射 17β-雌二醇（Ovx+Est）组。4 周后，通过尿动力学测量来确定收缩间隔和收缩压。采用 Western blot 和免疫组织化学法检测大鼠膀胱平滑肌中窖蛋白 2 和 3 的表达和细胞定位。
在膀胱测压图中，Ovx 组的收缩间隔（min）明显低于对照组（3.1±1.5），但雌激素治疗后增加（9.3±1.0）。相反，Ovx 组的平均收缩压（mmHg）高于对照组（26.2±2.3），但雌激素治疗后降低（23.8±3.5）。窖蛋白 2 和 3 的表达定位于平滑肌细胞膜上。卵巢切除术后，窖蛋白 2 和 3 的蛋白表达均显著降低，17β-雌二醇治疗后恢复至对照水平。
激素变化导致大鼠膀胱平滑肌中窖蛋白 2 和 3 的表达发生显著变化。这些发现提示这些分子可能在与激素变化相关的逼尿肌过度活动中具有功能作用。
