| Abstract: | Nitric oxide (NO) is a multifunctional messen-ger molecule produced through oxidation of L-arginine to L-citrulline by enzyme NO synthase (NOS). In the current study, mouse blastocysts were cultured in the different media, and the implantation capacity of blastocyst was evaluated by evaluating the percentage of embryos adhesion and out-growth after culture for 12, 24 or 48 h. Matrix metallopro-teinase-2 (MMP-2) mRNA was detected by RT-PCR, and MMP-2 protein was detected by gelatin zymography. Inhibi-tion of blastocyst adhesion and outgrowth was observed in embryo cultured with 500 mmol/L NOS inhibitor NG-mono- methyl-L-arginine (L-NMMA) alone; however, 100 mmol/L S-nitroso-Nacetylpenicillamine (SNAP), a NO donor, and 20 mmol/L cGMP analogue, 8-Br-cGMP could block this inhibi-tion. The expression and production of MMP-2 in the blas-tocysts were suppressed by L-NMMA, and SNAP or 8-br-cGMP could reverse this suppression. These results suggest that NO induces embryo implantation by cGMP sig-naling pathway. |
