Effect Of Nitric Oxide In The Process Of Implantation In Mice

Cormu uteri injection method was employed to explore the effect of nitrogen monoxidum (NO) on mouse embryo implantation in this study. in second day of pregnancy (D2) injected 0.2 mg the nitric oxide synthase (NOS) inhibitors of N-nitro - L-arginine methyl ester (L-NAME), or 10μg L-NAME0.2mg + SNP was injected in one of the cormu uteris, which the opposite one was treated as the control. Then mouse were killed by cervical dislocation on D4, D5, D6, D8 of pregnancy, and the number of successful implantion (implantion ratio) for the experimental cormu uteris and control ones were recorded respectively. Results showed that impantion ration declined after cormu uteri were treated with L-NAME (0.2 mg each) compared with the control, when the number of embryo implantation didn't affect when the cormu uteri injeced L-NAME 0.2 mg added NO donor nitroprusside (SNP). To approach NO's mechanism of action in the procedure of embryo implantation, all the mice were detected the endometrial MMP-9 mRNA gene expression level by RT-PCR method, study the endometrial MMP-9 gene expression levels in the Early embryos planting period, the embryos planting period and the later planting period and the endometrial MMP-9 gene expression levels effection by NO.The results showed MMP-9 activity dropped significantly in the side of the cormu uteri injection L-NAME 0.2 mg Compared with the control side; MMP-9 activity returned to normal when the cormu uteri injeced L-NAME 0.2 mg added NO donor nitroprusside (SNP). The results showed NO promote Mouse embryo implantation, may be affected by the activity of MMP-9.We have also observed the mouse uterus,uterus endomembrane and defilming membranization by the method of histological section and light microscope. The results showed pregnancy side's endometrial Obviously developed in the process of implantation, the epithelial cells increased,glandular organ developed,mesenchymal raritas,interstitial cells augmentation and significantly decidua transformation. comparison with inhibition side's endometrial the epithelial cells lower relatively,the lower number of glandular organ,endometrial pronounced degenerative in the later planting period and the matrix has become closer. Therefore, NO as a relaxation of smooth muscle and blood vessel expansion, has a very significant regulatory the endometrial expression MMP-9 mRNA. the endometrial MMP-9 gene expression dropped significantly by inhibition NO in the process of implantation, and it affect the development of endometrial and embryo implantation in the further.