INTENSITY OF FREE RADICAL PROCESSES IN THE POSTNUCLEAR FRACTION OF RAT KIDNEYS UNDER INFLUENCE OF LASER IRRADIATION AND ω-3 POLYUNSATURATED FATTY ACIDS

Introduction. The effect of laser irradiation on the body can lead to local tissue damage, which will be accompanied by changes in biochemical processes that occur in the kidneys. The direction of these changes is completely unclear, so the study of free radical oxidation of lipids and proteins as the main markers of oxidative stress in the body and their correction by ω-3 polyunsaturated fatty acids (PUFA) remains relevant. Aim. To evaluate the intensity of lipid peroxidation and oxidative modification of proteins in the postnuclear fraction of rat kidneys under the action of laser irradiation and additional administration of ω-3 PUFA. Methods. The studies used white outbred rats, which were irradiated daily for 4 minutes with a laser diode with a wavelength of 650 nm, power of 50 mW in the abdominal cavity at a distance of 10 cm from the skin surface. The state of lipid peroxidation (LPO) was determined by the level of primary, secondary and final products. The intensity of oxidative modification of proteins (OMP) was evaluated by the level of carbonyl derivatives and protein SH-groups. To correct the prooxidant state, the animals were additionally injected with ω-3 PUFA. Results. Low-intensity laser irradiation has a destructive effect on the cell membranes of the kidneys, which is expressed by an increase in primary, secondary and final products of LPO in phospholipid extracts and an increase in the intensity of OMP. The introduction of ω-3 PUFAs reduces free radical processes in the kidneys of irradiated rats, but this effect depends on the scheme of their introduction. ω-3 PUFAs do not show antioxidant effect under the conditions of their introduction after laser irradiation. Daily administration of ω-3 PUFA two hours before irradiation shows a slight antioxidant effect only in the initial stages of irradiation. Preliminary seven-day administration of ω-3 PUFA before laser irradiation is the most effective, as it helps to reduce free radical processes. Conclusion. It is established that ω-3 PUFAs are able to have a corrective effect on the action of low-intensity laser irradiation, which depends on the scheme of their introduction. The highest antioxidant effect is observed in groups of animals to which ω-3 PUFA was previously administered before the action of laser irradiation.

Regulation of free radical processes in healthy volunteers during experimental hyperthermia and in patients with coronary artery disease during summer heat waves

Background. In view of the worsening forecast for global temperature rise worldwide, it seems relevant to study the effects of abnormal heat waves on systemic regulatory processes in people with chronic diseases, in particular coronary artery disease (CAD).Aims. This study aimed to investigate the effect of hyperthermia on oxidative stress parameters in patients with various severity of CAD and in healthy subjects.Materials and methods. We studied the level of malonic dialdehyde (MDA) and the activity of Cu,Zn-containing superoxide dismutase (Cu,Zn-SOD) in healthy subjects under conditions of 30-day long simulated hyperthermia and in patients with different severity of CAD after the summer heat wavesResults. We revealed signs of oxidative stress in healthy volunteers during model hyperthermia that manifested as an increase in content of MDA in blood plasma. At the same time we observed increasing activity of Cu,Zn-SOD in erythrocytes that utilizes reactive oxygen species. The increase of Cu,Zn-SOD activity started with a certain latency what also can be explained by de novo enzyme biosynthesis induction. We also studied oxidative stress parameters in patients at high and moderate cardiovascular risk according to the SCORE risk chart with uncomplicated CAD course and in patients with complicated CAD with severe coronary damage according to angiography during the summer heat waves. We observed accumulation of MDA in blood plasma and increasing activity of erythrocyte Cu,Zn-SOD in patients with uncomplicated CAD. At the same time we noted that accumulation of MDA in blood plasma was not followed by any increase in activity of red blood cell Cu,Zn-SOD in patients with severe complicated CAD. This fact indicates dysregulation of free radical processes in patients with severe course of CAD during the heat waves.Conclusions. The dysregulation of free-radical processes in patients with a severe clinical course of CAD has been revealed.

Expression of protective proteins and morphological changes in the rat brain after prolonged exposure to dust

Introduction. The fundamental mechanisms of the body's pathological reaction to coal and dust exposure are hypoxia, excessive activation of free radical processes, structural and metabolic disorders in various organs. Organ-specific molecular defense mechanisms begin to function in the form of changes in the level of proteins with antihypoxic (HIF-3a), chaperone (HSP72), and antioxidant functions (HOx-1 - heme-oxygenase, Prx-1 - peroxiredoxin) under damaging effects. Its high level contributes to the restoration of cells' functional state or indicates significant damage in tissues. Hypoxia and free radical processes are known to lead to severe brain damage and behavioral disorders. To date, little is known about the expression of protective proteins and morphological changes in the brain under prolonged exposure to coal-rock dust on the body. The study aimed to learn the level of intracellular protective proteins HIF-3a, HSP72, HOx-1, Prx-1, and morphological changes in the brain in the dynamics of long-term dust exposure. Materials and methods. Sixty white male Wistar rats weighing 200-250 g of the same age took part in the experiment. Dust exposure was modeled by way of dynamic inhalation priming of rats with coal-rock dust (coal of a gas-fat brand) in an intermittent mode for 12 weeks. We perform morphological studies of the brain after 1, 3, 6, 9, and 12 weeks of dust exposure. The cytosolic fraction of brain tissue researchers determined the expression level of HIF-3a, HSP72, HOx-1, and Prx-1 by Western blot analysis. We selected the activity of free radical processes in the brain tissue. Results. Long-term exposure to coal-rock dust on the body at the morphological level in the brain revealed changes that indicate the development of hypoxia and activation of free radical processes: microvascular disorders, pericellular edema, severe dystrophic damage to neurons, focal loss of neurons, activation of glial cells. Activation of the protective proteins HIF-3a, HSP72, HOx-1, and Prx-1 in the early stages (1-3 weeks) of coal-dust exposure provided compensation for free radical processes in brain neurons. An increase in the duration of dust exposure of more than six weeks influences a low level of HSP72, but high HIF-3a and Prx-1, indicating an increase in hypoxic and free radical damage brain. Conclusions. The results obtained to expand the understanding of the morphological and molecular mechanisms that occur in the brain tissue during prolonged dust exposure to the body are essential for developing methods for organ-specific pharmacological correction.

Oxidative stress markers in patients suffering from opioid and psychostimulant dependence syndrome

Background. The available data from clinical studies suggest the essential role of free radical processes in the pathogenesis of drug dependence syndrome. At the same time, there is a limited understanding of using markers of oxidative stress in laboratory monitoring and prediction of drug pathology.Objective. To characterize changes in promising indicators of oxidative stress in patients with psychostimulant and opioid dependence syndrome.Material and Methods. The total study population was divided into three groups of men aged 23–35: healthy controls (n = 20), patients with the opioid (n = 20) and psychostimulant (n = 20) dependence syndrome. Patients were analyzed for the oxidative stress markers while being in therapy for addiction syndrome aimed at treating mental disorders and detoxification.Results. The study of antioxidant activity and blood plasma thiol groups did not reveal any significant differences between patients suffering from opioid and psychostimulant addiction. The values of the parameters mentioned above were maintained by 20–30% lower than the control indices throughout the entire study. The nature of changes in erythrocyte suspension parameters was not so unambiguous. Thus, patients with opioid dependence syndrome were characterized by a 91% increase in thiobarbituric acid (TBA)-reactive materials in the setting of a slightly altered state of the glutathione system parameters. Psychostimulant dependent patients revealed relatively low level of the products of biomolecule oxidative modifications in the erythrocytes that is 52% higher compared to the control values. It decreased during the therapy, but glutathione concentration reduction by 33% and an imbalance of glutathione metabolism were determined.Conclusion. The course of the opioid dependence syndrome is characterized by a pronounced intensification of free radical processes while the common trait for psychostimulant abusers is significant changes in the antioxidant defense system. Therefore, in the first case, it is most justified to conduct a laboratory assessment of indicators of oxidative damage, and in the second one, it is also advisable to determine the markers of the state of individual links of the antioxidant system.