D-AMINO ACIDS AND THEIR OXIDASE IN FARM ANIMALS - THE ROLE AND OPPORTUNITIES
In the article, the basic physiological and biochemical functions and the importance of D-amino acids and D-amino acid oxidase in mammalians are described. Serious attention is paid to metabolic role of D-amino acid oxidase in health and disease. D-amino acids and D-amino acid metabolizing enzyme has been discovered by Krebs 1935 (H. Krebs, 1972). Nowadays, most attention is given to the signal, communication and regulatory role of peroxisomes in metabolism. The peroxisomes are considered as candidate agents able to provide a relationship between the nervous and endocrine systems and participate in metabolism regulation in cells, organs and the body. Significant amounts of D-amino acids, the L-amino acids stereoisomers, are found in the peroxisomes of various organs and tissues: in the nervous system (J. Sasabe et al., 2014.), endocrine glands (A. D'Aniello et al., 2000), liver, kidney, breast, etc. (S.V. Khoronenkova, V.I. Tishkov, 2008). These active molecules provide communications in the neuronal network via the synapses of nerve endings (C.W. Morgans et al., 2013) and are involved in cell aging and apoptosis (A.V. Worms, 2010), biosynthesis and secretion of hormones, blood pressure regulation, maintenance of cell osmotic pressure (Y. Nishina, 2008), anti-inflammatory reactions and anti-carcinogenesis (G.H. Fisher, 1998). D-amino acid oxidase affects the activity of body as a whole in very diverse ways due to simultaneous engagement in diametrically opposite multi-parametric processes, such as regulation of cell level of D-amino acids and amino acid D-amines; the activity of central and peripheral nervous system; the maintenance of cell ecology; biosynthesis and secretion of epiphyseal melatonin (H.K. Park et al., 2007), hypothalamic releasing factors, pituitary, thyroid and steroid hormones (A. Santillo et al., 2014); defense against xenobiotics, microorganisms, viruses, stresses, and malignant tumors (R. Rana et al., 2012). Special attention the authors of this paper pay to the role of D-amino asides and D-amino aside oxidase in farm animals. World publications are mostly devoted to physical and chemical properties and the involvement of these agents in a number of neurodegenerative diseases and human clinical pathology of the central and peripheral parts of brain. As to farm animals, the data are almost completely absent. Recently, a growing body of in-deep examinations appear of the impact of D-amino acid oxidase and D-amino acids on the entire hierarchy of the endocrine system from the pineal gland, the hypothalamus and the pituitary gland to the ovaries and testes (S. Yasuaki et al., 2012). The studies are mostly focused on the regulation mechanisms of reproductive function in humans and animals. Elucidation of the involvement of D-amino acids and D-amino acid metabolising enzyme in excitation and inhibition processes in the central nervous system is of a particular interest for farm animal biology. Cognitive function in farm animals is of a separate interest as it is tightly associated with animal adaptability to commercial production, formation of the nervous system type and a reduced aggressiveness. Eventually, these will result in control of farm animal behavior and performance.