压力性尿失禁大鼠中环氧合酶2表达的变化及意义

The change of COX-2 expression in rats with stress urinary incontinence and its significance

目的压力性尿失禁(SUI)的发病机制研究较少。文中旨在检测环氧合酶2(COX?2)在SUI大鼠模型中的尿道、阴道、尿道平滑肌中的表达变化。方法健康雌性未育SD大鼠60只,雄性SD大鼠15只,合拢自然妊娠,取分娩后雌性大鼠分别行扩张阴道(单纯扩张组)、扩张阴道+切除卵巢(扩张+切除组)建立SUI大鼠模型,另使用正常妊娠分娩后大鼠为对照组,每组6只。通过喷嚏实验及尿动力学检查最大膀胱容量(MBC)和腹压漏尿点压(ALPP),荧光定量PCR、Western blot检测COX?2 mRNA及蛋白水平的表达,免疫组化检测COX?2在尿道、阴道、尿道平滑肌的表达。结果扩张+切除组、单纯扩张组ALPP较对照组明显下降,扩张+切除组较单纯扩张组明显下降(P<0.05)。单纯扩张组、扩张+切除组COX?2mRNA表达量[(1.40±0.07)、(1.75±0.10)]、蛋白的相对表达量[(1.64±0.05)、(1.95±0.08)]较对照组[(1.00±0.16)、(0.77±0.26)]均明显升高(P<0.001);扩张+切除组较单纯扩张组明显升高(P<0.05)。免疫组化结果显示,对照组、单纯扩张组、扩张+切除组阴道组织中COX2的染色强度表达积分依次为0.50±0.54、5.55±0.54、9.33±0.81,组间两两比较差异有统计学意义(P<0.05);尿道平滑肌组织中染色强度表达依次为0.66±0.51、5.33±0.51、8.50±0.54,组间两两比较差异有统计学差异(P<0.05)。结论切除卵巢后的雌激素下降可致COX?2表达的升高,COX?2与SUI的发病机制相关。

Objective There are a few researches on the mechanism of stress urinary incontinence(SUI).The article aimed to examine the changes of COX-2 expression in the urethra,vagina and urethral smooth muscle of SUI rat mode to evaluate the effect of estrogen on COX-2 expression.Methods Sixty unbearing healthy female SD rats and fifteen male SD rats were gathered for spontaneous delivery.SUI rat models were constructed using expanded vagina,expanded vagina+ovariectomy respectively after delivery,which were expanded vagina group and expanded vagina+ovariectomy group.Six successfully modeled rats were chosen for the follow-up experiment.SD rats modeled after normal pregnancy were the control group.Sneezing experiment and urodynamic examination were used to examine the maximum bladder capacity(MBC)and abdominal leak point pressure(ALPP).Fluorescent quantitative PCR and western blot were applied to detect the expressions of COX-2 mRNA and protein,and immunohistochemistry was used to detect the expressions of COX-2 in urethra,vagina and urethral smooth muscle.Results Compared with control group,ALPP in two experimental groups were significantly decreased,among which ALPP in expanded vagina+ovariectomy group was significantly decreased in comparison to expanded vagina group(P<0.05).Compared with control group,the expressions of COX-2 mRNA and protein in expanded vagina group and expanded vagina+ovariectomy group were significantly higher,among which the figures in expanded vagina+ovariectomy group were significantly higher than those in expanded va-gina group(P<0.05).The result of immunohistochemistry showed staining intensity integral expression of COX-2 in vaginal tissues of control group,expanded vagina group and expanded vagina+ovariectomy group were 0.50±0.54,5.55±0.54,9.33±0.81,so differences between any two groups were of statistical significance(P<0.05);staining intensity integral expression of COX-2 in urethral smooth muscle of control group,expanded vagina group and expanded vagina+ovariectomy group were 0.66±0.51,5.33±0.51,8.50±0.54,so differences between any two groups were of statistical significance(P<0.05).Conclusion The expression of COX-2 was related to the mechanism of SUI.The decrease of estrogen may increase the expression of COX-2 in SUI rats,which supports the treatment of SUI.