FEATURES OF THE MECHANISMS OF ANTIOXIDANT PROTECTION IN PREMATURELY BORN CHILDREN IN CONDITIONS OF GENERIC OXIDATIVE STRESS

Abstract

Introduction. A universal reaction which accompaning stressful situations in the body is the reaction of oxidative stress. In particular, this condition is typical for the childbirth in connection with a cardinal change of the conditions of existence - the transition from intrauterine to extrauterine existence. Adaptation of the newborn in terms of generic oxidative stress depends from the balance of the pro-oxidant and antioxidant systems, which, in the physiological course of pregnancy and childbirth, works on the principle of feedback. This mechanism can be both physiological and destructive in conditions of hypoxia and premature birth due to the morpho-functional immaturity of the organism. Goal. To investigate the features of the functioning of the pro-oxidant and antioxidant defense systems in prematurely borned children, taking into account the severity of perinatal pathology. Materials and methods. The 1st group comprised 100 premature infants who had clinical manifestations of adaptation disorders in the early neonatal period against the background of morphofunctional immaturity. In particular, IА subgroups were children who had clinical signs of neonatal pathology of moderate severity (49 people). IB subgroup - children who had a difficult birth condition (51 people). Group II consisted of conditionally healthy prematurely born children (27 people). The total number of examined newborns was 127. The severity of the condition of newborns was determined taking into account the peculiarities of adaptation at birth and the dynamics of the course of diseases. Since the pathology studied it was rather heterogeneous, in order to avoid inconsistency in the interpretation of the results and additional statistical errors, a general methodological approach was used, which provided for the distribution of children in subgroups not in terms of nosological forms but in terms of the severity of the general condition, which determined by clinical signs, and , using a standardized assessment of the Scale of Acute Physiology of the Newborn and Ball evaluation of the severity of newborns th. The parameters of the pro and antioxidant systems of the organism examined: the degree of oxidative modification of proteins, the content of HS-groups in the blood, the level of ceruloplasmin, and the activity of catalase. The research was conducted during 2013 - 2016. on the basis of intensive care unit of neonatal city clinical maternity hospitals №1 and №2 Chernivtsi, using the possibilities of the biochemical laboratory of the department of bioorganic and biological chemistry and clinical biochemistry of the Higher State Educational Institution of Ukraine Bukovina State Medical University (Chernovtsy, Ukraine). Medico-social data of the mother's history, information on the features of the course of pregnancy and childbirth, the results of a clinical examination of newborns, as well as data from additional paraclinical methods of research added to a computer data bank. The analysis of statistical data was carried out using a package of applied programs for conducting biomedical research STATGRAPHICS (2001, 2005). Results of the study. The parameters of free radical oxidation and antioxidant protection of the organism under conditions of generic oxidative stress in newborns studied taking into account the gestational age and severity of the condition of perinatal pathology. An increase in the activity of indicators of the prooxidant system in case of deficiency of antioxidant defense units in severe forms of perinatal pathology in premature infants has been revealed. Uncontrolled enhancement of the processes of free radical oxidation in the first day of life with insufficient activity of the antioxidant defense system disrupts the structure and function of cell membranes, causing a cytolytic syndrome, leading to an increased risk of various pathological conditions, reducing the ability of the newborn to adapt to extrauterine conditions of life. The conclusion is made about the expediency of using the above indicators to assess the severity of ante / intranatal hypoxia, predicting its harmful effects on health and preserving the quality of life. Conclusions 1. During the transition of the newborn to independent breathing, the activity of oxidation-reduction processes in the body increases, which leads to an enhanced formation of reactive oxygen species. 2. Uncontrolled strengthening of processes of free radical oxidation in the first day of life of a child with insufficient activity of the antioxidant defense system in prematurely born children reduces the reserves of adaptation of the organism to new conditions of existence, causes the development of various pathological conditions. 3. To assess the depth and severity of hypoxic damage to children in case of premature birth, it is advisable to use the study of free radical oxidation and antioxidant protection systems to determine the risk of adaptation disorders in the early neonatal period.