Feng Chun, Sun Chao-Chao, Wang Ting-Ting, He Rong-Huan, Sheng Jian-Zhong, Huang He-Feng
Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China.
Menopause. 2008 Jul-Aug;15(4 Pt 1):648-54. doi: 10.1097/gme.0b013e31816086ef.
Aquaporins (AQPs) may be involved in the occurrence of abnormal uterine bleeding as the mediators between ovarian steroids and cyclic endometrial changes. The aim of the present study was to investigate the characteristics of endometrial AQPs in women with anovulatory uterine bleeding and explore the relationship between endometrial AQPs and ovarian steroids.
Sixty-one women with premenopausal anovulatory uterine bleeding and 108 women with normal cycles were involved in this study. Endometrial biopsies were obtained from the women with anovulatory uterine bleeding and normal control women. Serum estradiol and progesterone concentrations were measured with enzyme-linked immunosorbent assay on the same day as an endometrial biopsy was performed. AQP1 and AQP2 mRNA expression was evaluated using reverse-transcriptase polymerase chain reaction. Immunohistochemistry was used to localize AQP1 and AQP2 in the endometrium, and their expression was quantified by an image analysis/measuring system.
AQP1 was located in the endothelium of small vessels, whereas AQP2 was mainly found in luminal and glandular epithelium. The expression levels of AQP1 and AQP2 mRNA and protein were higher in the secretory phase than those in the proliferative phase (P < 0.01) in normal endometrium, and their expression was related to serum steroid hormones (P < 0.01). However, the expression of AQP1 and AQP2 decreased in the endometrium in anovulatory uterine bleeding comparing with normal endometrium (P < 0.01). The correlation between AQP expression and ovarian steroids vanished (P > 0.05) in anovulatory uterine bleeding.
Our findings indicate that cyclic expression of endometrial AQP1/AQP2 correlated with steroid hormone levels may be essential to normal endometrial function and decreased AQP1/AQP2 expression in endometrial vessels or epithelium may be involved in the occurrence of anovulatory uterine bleeding.
水通道蛋白（AQPs）作为卵巢甾体激素与子宫内膜周期性变化之间的介质，可能参与异常子宫出血的发生。本研究旨在探讨无排卵性子宫出血患者子宫内膜AQPs的特征，并探究子宫内膜AQPs与卵巢甾体激素之间的关系。
本研究纳入61例绝经前无排卵性子宫出血患者和108例月经周期正常的女性。对无排卵性子宫出血患者和正常对照女性进行子宫内膜活检。在进行子宫内膜活检的同一天，采用酶联免疫吸附测定法检测血清雌二醇和孕酮浓度。使用逆转录聚合酶链反应评估AQP1和AQP2 mRNA表达。采用免疫组织化学法对子宫内膜中的AQP1和AQP2进行定位，并通过图像分析/测量系统对其表达进行定量。
AQP1位于小血管内皮，而AQP2主要见于腔上皮和腺上皮。正常子宫内膜中，AQP1和AQP2 mRNA及蛋白的表达水平在分泌期高于增殖期（P<0.01），且其表达与血清甾体激素有关（P<0.01）。然而，与正常子宫内膜相比，无排卵性子宫出血患者子宫内膜中AQP1和AQP2的表达降低（P<0.01）。在无排卵性子宫出血中，AQP表达与卵巢甾体激素之间的相关性消失（P>0.05）。
我们的研究结果表明，子宫内膜AQP1/AQP2的周期性表达与甾体激素水平相关，这可能对正常子宫内膜功能至关重要，而子宫内膜血管或上皮中AQP1/AQP2表达降低可能参与无排卵性子宫出血的发生。
