Журнал «Здоровье ребенка» 8 (51) 2013
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Oxidative stress and antioxidant defenses in children with varying degrees of control over bronchial asthma
Авторы: Litvinets L.Ya. - State Higher Educational Institution «Ivano-Frankivsk National Medical University», Ivano-Frankivsk, Ukraine
Рубрики: Педиатрия/Неонатология
Разделы: Клинические исследования
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Introduction. Important role in the pathogenesis of the vast majority of respiratory tract diseases, including bronchial asthma ( BA) plays an oxidative stress (OS), which is the main cause of the imbalance in the system of «oxidants — antioxidants», expressed by excessive formation of reactive oxygen species and weakening performance of antioxidant protection (AOP). This feature of respiratory disease is caused by the fact that the respiratory tract is constantly exposed to the direct effects of exogenous oxidants that are in the air (xenobiotics), unsaturated fatty acids lung tissue are the substrate for the reaction of lipid peroxidation (LPO), pollutants and microorganisms cause activation of phagocytes, which produce a substantial amount of reactive oxygen species. Today it is proved that in the condition of oxidative stress under the action of reactive oxygen species not only lipids have the peroxidation, but also proteins of the plasma membrane. It is believed that the negative effect of oxidation- modified proteins in cells is connected with the fact that oxidized proteins are a source of free radicals that deplete supplies of cellular antioxidants. Level indicators of oxidative modification of proteins (OMB) compared with the level of lipid peroxidation is informative marker of the presence of oxidative stress in the body. Mechanisms of free radical oxidation of macromolecules of asthma remain poorly understood and not fully open.
antioxidant system, asthma, children.
Aim: to evaluate the status of prooxidant and antioxidant system in children with varying degrees of control over asthma.
Materials and methods. The study involved 107 children aged 10 to 18 years, patients with asthma exacerbation. Regarding the level of controlled asthma children were distributed as follows: 34 (31.8 %) — a controlled (CBA), 47 (43.9 %) — is partly controlled (PCBA) and 26 (24.3 %) — with uncontrolled bronchial asthma (UCBA). The control group consisted of 10 healthy children of similar age. To study the condition of oxidation- modified proteins in cells the indicators of OMB were investigated. The superoxide dismutase (SOD) was determined by the method of S. Chevari et al. Quantitative determination of catalase in serum was performed by the method of A.N. Bach and S. Zubkov. The results were analyzed using computer packages licensing program «STATISTICA» StatSoft Inc. and Excel XP for Windows.
Results and discussion. Analysis of the determination of content of oxidation- modified proteins in cells (OP) products in serum of patients with asthma means the presence of their oxidative stress, the severity of which is to some extent determined by the level of asthma control. Thus, the content of OMB — 356 in all examined groups with asthma significantly exceeded the similar indicator of healthy (pN < 0.05). Research content of OMB — 370 in serum of children with varying degrees of control over asthma revealed that in all groups there was an increase in its level compared to healthy and in children with CBA and UCBA this difference was reliable (pN < 0.05). The another trend is noted in the indicators of content of OMB — 430. Thus, the likely increase in its level occurred only in children with UCBA (pN < 0.05). In other groups examined with asthma indicators of OMB — 430 were close to those in healthy patients. Content of OMB — 530 and its level in children with UCBA practically has no difference from the rate of the control group, and the children with PCBA and CBA was noted probable decline compared with healthy (pN < 0.05). Research of contents of enzymatic antioxidants in children with varying degrees of control over asthma showed that in patients with UCBA and PCBA AO defense characterized by probable decrease in the activity of catalase and SOD (pN < 0.05), indicating that achievement of functional depletion of enzymatic chain of AOP in this category patients. Thus, in the patients with CBA AOP values were close to those of the healthy group. Thus, these results demonstrate a systemic activation of OCD in children with asthma, which may be due to prolonged inflammation. Strengthening of processes OP is accompanied by a weakening of AOP, which is manifested by decreased activity of SOD, which catalyzes the dismutation of superoxide anion radicals and antioxidant barrier is the first line of defense — catalase — shows a significant weakening of the protection of the respiratory tract in asthma accumulation of reactive oxygen species.
Conclusions. 1. Children with CBA can have a development of oxidative stress, which manifests a significant increase in the accumulation of content of products of OCD with growing tension of adjustment mechanism and protective contact of AOP system. 2. Asthma in children is characterized by heterogeneity and mechanisms of enzymatic peroxidation of prooxidant system, which is determined by the severity of illness and can make a pathogenetic basis for predicting the severity of asthma in children.