Jones R L, Critchley H O
Prince Henry's Institute of Medical Research, Clayton, Victoria, Australia.
Hum Reprod. 2000 Aug;15 Suppl 3:162-72. doi: 10.1093/humrep/15.suppl_3.162.
The levonorgestrel releasing intrauterine system (LNG-IUS) provides a novel contraceptive method. Intrauterine LNG induces a dramatic transformation of the endometrium, characterized by extensive decidualization. This is associated with strong expression of local factors associated with decidualization, including prolactin receptor and insulin-like growth factor binding protein-1. A striking discovery was the down-regulation of oestrogen and progesterone receptors in all components of the endometrium after insertion of the LNG-IUS, with a gradual return between 6 and 12 months post-insertion. Preliminary findings suggest that androgen receptors are expressed during this time. Elevated leukocyte infiltrate is observed 1 month after insertion of the device, comprising large granular lymphocytes and macrophages. We examined a number of local mediators implicated in menstruation and breakthrough bleeding episodes. Expression of the chemokine interleukin-8 was enhanced after insertion of the device, with a notable decrease apparent 6 months post-insertion. Cyclooxygenase-2 was similarly strongly expressed in the first months after LNG-IUS insertion, in contrast to an initial suppression of prostaglandin dehydrogenase activity. By deduction it appears that higher local concentrations of prostaglandins are present in the initial period of local LNG exposure. Taken together these data suggest that in the first months following LNG-IUS insertion steroid receptor content is significantly decreased, resulting in the altered expression of many locally acting mediators which may be involved in breakthrough bleeding episodes.
左炔诺孕酮宫内节育系统（LNG-IUS）提供了一种新型避孕方法。宫内左炔诺孕酮可诱导子宫内膜发生显著转变，其特征为广泛的蜕膜化。这与蜕膜化相关的局部因子的强烈表达有关，包括催乳素受体和胰岛素样生长因子结合蛋白-1。一个惊人的发现是，在插入LNG-IUS后，子宫内膜所有成分中的雌激素和孕激素受体均下调，在插入后6至12个月之间逐渐恢复。初步研究结果表明，在此期间雄激素受体有表达。在插入该装置1个月后观察到白细胞浸润增加，包括大颗粒淋巴细胞和巨噬细胞。我们研究了一些与月经和突破性出血事件有关的局部介质。插入该装置后趋化因子白细胞介素-8的表达增强，在插入后6个月明显下降。与前列腺素脱氢酶活性最初受到抑制相反，环氧化酶-2在LNG-IUS插入后的最初几个月也有类似的强烈表达。由此推断，在局部左炔诺孕酮暴露的初始阶段，局部前列腺素浓度较高。综合这些数据表明，在插入LNG-IUS后的最初几个月，类固醇受体含量显著降低，导致许多可能参与突破性出血事件的局部作用介质的表达发生改变。
