Marakushyn D. I., Isaev I. M.

ASSESSMENT OF SEROTONIN AND KYNURENIN METABOLISM OF TRYPTOPHAN STATE IN YOUNG PERSONS WITH ARTERIAL HYPOTENSION

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About the author:	Marakushyn D. I., Isaev I. M.
Heading	CLINICAL MEDICINE
Type of article	Scentific article
Annotation	Introduction. Mechanisms of primary arterial hypotension can not be explained by violation of a single neurotransmitter system, as was shown in our previous studies. So the next stage of our study was to investigate the activity of serotonin and kynurenine pathways of tryptophan metabolism. This amino acid is a source of production of nicotinamide coenzymes, nicotinic acid, biogenic monoamine serotonin, the hormone melatonin, which significantly affect the physiological and metabolic processes in different systems, organs and tissues. The aim of the research: To determine the possible features of the activity of serotonin and kynurenine metabolism of tryptophan. Methods. The research involved 128 young persons, including 50 persons with normal blood pressure level. The first examined group included 39 persons whose level of MAP defined as 80-75 mm. The second group included 39 persons with MAP level - 74,9-70 mm. The colorimetric method was used to determine the 5-Hydroxyindoleacetic acid (5-HIAA) in urine. The fluorescence method was used to determine the N-methyl nicotine amide (N-MNA) in urine. Statistical analysis was performed using the computer application package for statistical data processing Statistica 6.1 (StatSoft, Inc., USA). Results. The results showed a statistically significant (p <0.001) compared with the control, higher urinary excretion of 5- HIAA: group I in 2.4 times, and for group II – in 3 times. The excretion of N- MNA was more expressed. In persons of group I the significant (p <0.001) compared to control an increase in the final metabolite of tryptophan metabolism by kynurenine pathway in 2.8 times, and in Group II - in 3.3 times was observed. The content of N- MNA was increased (p = 0.015) by 18% in the experimental group II compared with group I. To clarify the nature of the shifts in the metabolic pathway of tryptophan metabolism the ratio N-MNA / 5 HIAA was calculated. In individuals of group I the ratio was increased by 25%, but in the general statistical picture it was not statistically significant (p = 0.29). This dynamic change suggests some prevalence of kynurenine pathway of tryptophan metabolism, which may be accompanied by a decrease in serotoninergic activity. Reducing serotoninergic activity, according to the literature data, may be accompanied by a decrease in heart rate variability, which is considered as an adverse prognostic marker for cardiovascular disease. It is proved that serotonin plays an important role in the limbic-reticular brain structures directly involved in the central regulation of vascular tone. Conclusion: In the examined persons an increase of urinary excretion of - 5-Hydroxyindoleacetic acid and N-Methylnicotinamide with an increase in the ratio of N-MNA / 5-HIAA was revealed, this point shows some prevailing exchange of kynurenine pathway of tryptophan metabolism and decrease in serotoninergic activity.
Tags	arterial hypotention, humoral regulation, serotonin, kynurenin, tryptophan
Bibliography	Bogdanova І.V. Stan pokaznikіv obmіnu triptofanu u pacієntіv іz hvoroboju Parkіnsona / І.V. Bogdanova // Ukraїns'kij medichnij chasopis.-2011.-№5(85) IX-X.-C. 116-119 Izzatizade K. F. Narushenija obmena serotonina v patogeneze zabolevanij nervnoj sistemy / K. F. Izzatizade, A. V. Basha, N. D. Demchuk // Zhurnal nevrologii i psihiatrii im. S. S. Korsakova. - 2004. - № 9. – S. 62-70 Kamyshnikov V. S. Kliniko-biohimicheskaja laboratornaja diagnostika / V. S. Kamyshnikov / Spravochnik : V 2-h tomah. - 2-e izd. - Minsk: Interpresservis, - 2003. - T. 2. - 463 s. Booij L. Tryptophan depletion aff ects heart rate variability and impulsivity in remitted depressed patients with a history of suicidal ideation / L. Booij [et al.] // Biol. Psychiatry. – 2006. – Vol. 60, № 5. – P. 507-514. Huff W. The fluorescent consenderation product of  N-methylnicotinamide and acetone. A sensitive method for the determination of N-methylnicotinamide in urine / W. Huff, W. A. Perlsweig // Biological Chemistry. – 1947. – Vol. 167, № 1. – P. 157-167. Murray R. K. Harpers Biochemistry / R. K. Murray, D. K. Granner, P. A. Mayes. // – New Jersey: Prentice Hall, - 1996. – 868 p. Yiquan Chen. Kynurenine Pathway Metabolites in Humans: Disease and Healthy States/ Yiquan Chen, Gilles J. Guillemin // International Journal of Tryptophan Research. – 2009.-Vol.2.-P.1-19.
Publication of the article	«World of Medicine and Biology» №1(48), 2015 year, 046-049 pages, index UDK 612.143:616-07