Investigating the role of nitric oxide inhibition on developing chick embryo liver development by histological, histochemiacal and immunohistochemiacal methods

The liver development starts at 4th day (HH stage 24) with the development of the liver bud and together with the very fast developmental stage, and at the 7th day (HH stage 29) third lobe develops from the ventral of the second lobe and development of the liver completes. It will partly continue developing after the 8th day with the growth phase. Nitric oxide (NO) is an inorganic free radical that secreted primarily from the epithelial cells and has roles on physiology events like defense against the microorganisms. L-Nitro-Arginine-Methyl-Ester (L-NAME) can act as a NOS substrate agent, and therefore, is a non-selective inhibitory for using the inhibition of both endothelial NO and inducible NO synthesis both in vivo and in vitro with non-specific matter. The purpose of our study is detecting structural anomalies on chick embryo and liver development in correlation with completely inhibiting or diminishing of NO synthesis simultaneously. In our study, Leghorn type embryonic chick eggs has been used. Eggs of both sham and experiment group has been incubated in a condition that have 37 ± 0.5°C heat and 60% ± 0.5 moisture level. At experiment group embryos, L-NAME (SCBT- sc-200333A) at two different doses (15-30 mg/ kg) in egg yolk at 4th, 5th, 6th and 7th days. 24 hours after the application, embryos were fixated and livers were used for routine histology. At the liver tissue, histologically; increasing of mitotic cells, malfunction at the cordon forming capabilities of hepatocytes, expansion at the sinusoids, endothelial cell loss, and stacking of erythrocyte clusters at sinusoids and necrotic areas has been observed. At the sham group, the immunoreactivity of eNOS and iNOS has been detected at the pheripheral part where ephielial-mesenchymal transtition occurs at the developing liver tissue, showed weak immunoreactivity at 5th days and increase with the development and shows maximum staining at the day 7. Also it has been showed that eNOS rectivity is more powerful than iNOS reactivity Together with the L-NAME treatment, eNOS and iNOS immunoreactivity has been dropped at the all groups. At the 6 days 15 mg/kg group, eNOS is more powerful from the iNOS staining, and at the other application groups, iNOS is more present from the eNOS. At the embryonic development process, NO has positive effects on embryos, and in case of NO inhibitor agent presence, decreased NO has general effects on embryonic morphology and can induce histopathologic changes especially on liver. With this status, it is concluded that NO inhibition might affect lifespan and life quality in embryo development negatively.