一氧化氮对小鼠胚胎着床的作用

The Role of Nitric Oxide in the Process of Implantation in Mice

为探讨一氧化氮 (NO)在胚胎着床中可能发挥的作用及其机制 ,进行小鼠胚胎着床实验 ,分 3个实验进行。实验 1及实验 2 ,于小鼠妊娠第 3d和第 1～ 6 d分别腹腔内注射 N-硝基 - L-精氨酸甲酯〔L- NAME,一氧化氮合酶(NOS)的非特异性竞争抑制剂〕 0 .5～ 5 mg和 3m g,观察其对胚胎着床的影响。实验 3,给予 L- NAME+L-精氨酸(NO的前体 ) ,观察 L-精氨酸对 L- NAME作用的影响 ,并评价胚胎发育情况。上述 3个实验均取子宫内膜行组织学检查。结果发现 :与对照组相比 ,妊娠第 3d腹腔注射 L- NAME1～ 5 m g可减少胚胎的着床位点数 (P<0 .0 5 ) ,腹腔注射 4、 5 mg的 L- NAME可完全抑制小鼠胚胎着床的发生。围着床期 (妊娠 3～ 5 d)给予 L- NAME均可减少胚胎着床位点数。此时 ,子宫内膜血管通透性的改变被抑制 ,缺少蜕膜样变 ,同时胚胎发育阻滞。 L- NAME的这种抑制作用可被同时给予的 L-精氨酸抵消。提示 NO通过增加子宫内膜的血管通透性。

To evaluate the role of nitric oxide in the embryo implantation in mice, three experiments were carried out using the mice implantation model. In the experimentⅠand experimentⅡ, N G nitro L arginine methyl ester (L NAME), the non specific NOS inhibitor, was administered intraperitoneally at doses of 0.5 mg 5 mg on the day 3 of pregnancy and at dose of 3 mg on different days of pregnancy (day 1-6) . In the experiment Ⅲ, L aragnine, a donor of NO, was co administered with L NAME to evaluate the effect of L aragnine on L NAME, and the embryo development was assessed. In all these three experiments, the endometrium was histologically examined. Results showed compared with the control groups intraperitoneal administration of a dose of L NAME between 1 and 5 mg on the day 3 of pregnancy led to the decrease in the number of implantation sites ( P <0 05), and 4 to 5 mg of L NAME caused inhibition of implantation completely. L NAME resulted in failure of pregnancy when administrated at 3 mg between day 3 and 5 of pregnancy. The characteristic vascular permeability changes and decidualization in the endometrium were significantly attenuated and embryo growth was retarded. The L NAME mediated effects were significantly reversed when L aragnine was co administered with L NAME. This study demonstrated that NO promoted the implantation in mice through regulating the permeability and decidulization of endometrium and the development of embryo.