The role of nitric oxide in embryogenesis of egg and meat hens

It is known that nitric oxide (NO) mediates the regulation of smooth muscle tone in the blood vessels and the gastrointestinal tract, the central and autonomic nervous systems activity, differentiation and apoptosis in tissues, immune response, and gene expression in animals and humans. This is a short-lived substance oxidized rapidly to nitrate and nitrite. Embryogenesis is associated with the synthesis of nitric oxide (NO) and accumulation of its metabolites in embryo. Nevertheless, the mechanism of this relationship is unknown. In this paper we reported the results of comparing dynamics of the NO metabolite levels in the parts of and a whole embryo in the layers and broiler chicks. Incubated eggs were examined in the breeds (Andalusian Blue, Yurlovskaya Golosistaya, Golubaya Myasoyaichnaya, Cochin White, Brahma Dark, Brahma Pale, P-11, Cornish, Plymouth Rock, Malay fighting hens, Uzbek fighting hens), some lines (Х1, Х2, Х12, Х34 of Hysex White cross, B5, B6 and B56 of Cornish, B7, B9, and B79 of Plymouth Rock), and four crosses (SP 789, Hysex White, Smena 8, Cobb 500). The NO metabolites were detected using developed enzymatic sensor. The test is based on catalase inhibition by nitrite, nitrosothiols (RSNO), Fe-dinitrosyl complex and nitro derivatives of high-molecular compounds (RNO 2) in the presence of halide ions, repressed by the factors different for each class of compounds. The close correlation was observed between meat productivity of adult poultry and NO metabolites accumulation in different embryo parts. The NO metabolite accumulation differed up to 100 times in meat- and egg-hen embryos, and in meat-egg hens and mini-hens the intermediate parameters were indicated. It was shown that nitrate as a final metabolic product was accumulated in the muscle of embryo. Due to time when the most intensive accumulation occurs in ontogenesis (3 days), some factor rather than the muscle itself, but influencing muscle histogenesis could be considered as the main agent involved in NO metabolism. Nitric oxide as a mediator can either activate this agent, or affect its synthesis.