Expression Of NNOS And INOS MRNA In The Early Embryonic Development Of Mice

Nitric oxide (NO) is a free radical molecule which has biological activity and is able to dissolve water and fat. The property of NO in chemistry reaction is reactive. As a signaling molecule, it plays an important role in many physiological processes, such as host defence mechanisms, neuronal signal transmission and vasodilation. NO is produced when the ni tri c oxide synthase (NOS) catalyzes the oxidation of L-arginine to L-citrul.line. Various isoforms of NOS have been identified and include neuronal nitric oxide synthase (nNOS), inflammatory or macrophage nitric oxide synthase (iNOS), and endothelial nitric oxide synthase (eNOS). The amount of NOS in some tisse can respond linearly the amount of NO in this tissue because NOS is the rate-limiting enzyme of in the process of generating NO.In recent years, many studies demonstrate that NO also exerts in early embryo development both in vivo and in vitro. Early embryo development is a key stage and is regulated by many factors, including NO, but the regulating mechanisms of NO during early embryo development are not clear now. In order to Probe into effects of NO on early embryonic development deeply, the activity of nNOS and iNOS mRNA in the early embryonic development of the mouse was examined by the RT-PCR . Expression of nNOS mRNA was initially observed in the 1 cell stage embryo of the mouse and 2 cell stage embryo and the level of expression gradually reduced. Just blastula expressed iNOS mRNA. These results confirm that NO play an important role in early embryonic development in mice through transmiting signal and promoting differentiation of early embryo.