The state of peroxidation processes in the basal nuclei of the brain under conditions of an altered photoperiod

The state ofperoxidation processes in the basal nuclei (the nucleus caudatus, globus pallidus, nucleus accumbens, amigdaloid complex) of the rat's brain under conditions of an altered photoperiod has been studied. A disturbance of regular photoperiodicity was shown to result in metabolic changes in the mentioned structures of the brain. Enhancement of the processes of lipid and protein peroxidation was observed in the basal nuclei under constant light, the intensity of fibrinolysis and proteolysis increases, the activity of the enzymes of antioxidant defense decreases. Heterodirectional changes of fibrinolysis and proteolysis in individual structures, a decrease of free radical processes against a background of accumulation of modified proteins were observed under conditions of constant darkness.     

The relationship between the proteolytic activity in the basal nuclei and locomotion in the open-field test under the conditions of an altered photoperiod

The effect of an altered photoperiod on the proteolytic activity in the basal nuclei, including the caudate nucleus, globus pallidus, nucleus accumbens, and amygdala complex, and rat behavior in the openfield test was studied. The altered photoperiod modulated the functional state of the basal nuclei, which was reflected in the locomotor activity of the animals.

     

Triiodothyronine and melatonin influence antioxidant defense mechanism in a teleost Anabas testudineus (Bloch): in vitro study

The effect of the hormones triiodothyronine (T3) and melatonin on antioxidant defense system was studied in 6-propyl thiouracil (6-PTU)-treated or photoperiod-exposed teleost Anabas testudineus. 6-PTU (2 microg/g) treatment or photoperiod exposure (24 h) increased malondialdehyde (MDA) and conjugated dienes (CD) concentrations, indicating increased lipid peroxidation (LPO) in the experimental conditions. T3 or melatonin (10(-6) M) treatment for 15 min in vitro in PTU-treated fish reversed the activity of superoxide dismutase (SOD), catalase and glutathione content. T3-treated group showed no change in glutathione peroxidase (GPx) activity, whereas melatonin treatment decreased its activity. T3 inhibited glutathione reductase (GR) activity. Photoperiod exposure (physiological pinealotomy) induced a stressful situation in this teleost, as evidenced by LPO products and antioxidant enzyme activities. Melatonin and T3 treatment for 15 min in vitro also reversed the effect of photoperiod on peroxidation products and the SOD and catalase activities. GR activity decreased in photoperiod-exposed group and melatonin and T3 treatment reversed the activities. The antioxidant enzymes responded to the stress situation after 6-PTU treatment and photoperiod exposure by altering their activities. The study suggested an independent effect of T3 and melatonin on antioxidant defence mechanism in different physiological situations in fish.     

The intensity of lipid peroxidation and enzymatic antioxidative activity in potato leaves under action of drought and polystimulin K

The influence long-term soil drought and potato plants treatment by synthetic analog of cytokinin--polystimulin K on intensity of lipid peroxidation processes and enzymatic antioxidative activity have been investigated. It has been found, that the drought induced the shift of prooxidative-antioxidative balance in respect of lipid peroxidation activation in the potato leaves. It was accompanied by the increase of the ethylene output, membrane permeability, as well as decrease of the lipids content and increase in the enzymatic antioxidative activity (catalase and peroxidase). It is shown, that the intensity of peroxidation processes was higher in budding phases, while enzymatic antioxidative activity was higher in flowering phases in potato plants. Plant exogenous treatment by polystimulin K induced both the decrease in peroxidate oxidation processes, stabilization of catalase and peroxidase activity, as well as the increase in potato resistance to drought.     

Impact of chromium on lipoperoxidative processes and subsequent operation of the glutathione cycle in rat renal system.

Oral administration of K2Cr2O7 to male albino rats at an acute dose of 1500 mg/kg body wt/day for 3 days brought about sharp decrease in the activities of glucose-6-phosphate dehydrogenase and glutathione reductase of kidney epithelial cells. The scavenging system of kidney epithelium is also affected as evident by the highly significant fall in the activities of glutathione peroxidase, superoxide dismutase and catalase which ultimately leads to the increase in lipid peroxidation value in kidney cortical homogenate. However, glutathione-s-transferase activity in cytosol and glutathione and total thiol content in cortical homogenate were not altered. Chronic oral administration of K2Cr2O7 (300 mg/kg body wt/day) for 30 days to rats lead to elevation in the activities of glutathione peroxidase, glutathione reductase, glutathione-s-transferase, superoxide dismutase and catalase with no change in glucose-6-phosphate dehydrogenase activity in epithelial cells. This might lead to the increase in glutathione and total thiol status and decrease in lipid peroxidation value in whole homogenate system.     

Lipid peroxidation in the synaptosomal and mitochondrial fractions of separate brain structures in hypoxia

The paper studies intensification of lipid peroxide oxidation in separate brain structures (the medulla oblongata, cerebellum, visual and sensomotor cortex), synaptosomal and mitochondrial fractions under hypoxia. It has been established that acute hypoxia increases accumulation of lipid peroxidation (LPO) products, hydroperoxide and malonyl dialdehyde. Intensification of LPO in synaptosomes and mitochondria is more pronounced as compared to the whole structures. Preliminary treatment with antioxidants (vitamin E and ionol) considerably suppressed LPO intensity under both hypoxia and hypoxia with reoxygenation. Intensification of LPO in synaptosomes and mitochondria is suggested to be the key point in structural-functional disturbances of the nervous system under hypoxia and ischemia.     

Motility of rats exposed to an altered photoperiod in the open field test

Motility of rats exposed to an altered photoperiod has been studied in the open field test. It has been shown that physical activity of rats kept in the dark declined. The correlation parameters of locomotor activity as compared with previous data changed in animals kept in continuous light.     

Age-Related Peculiarities of the Control of Respiration and Their Correlation with the Intensity of Free-Radical Processes

We describe the results of a study of the relations between the control of the respiratory function in isocapnic increasing hypoxia and the intensity of free-radical processes in groups of healthy young and aged subjects. It is known that aging is accompanied by some weakening of the response of the respiratory system to hypoxia with no considerable changes in the indices of ventilation in the resting state. Aged subjects, as compared with young tested persons, are characterized by a decrease in the activity of catalase, the absence of significant differences in the activity of superoxide dismutase, and a trend toward an increase in the content of products of lipid peroxidation in the blood. We discuss possible mechanisms mediating age-related modifications in the system of control of respiration and consider shifts in the system of pro/antioxidant balance and intensification of peroxidation processes against the background of a decreased activity of catalase primary changes responsible for the above modifications. These effects lead to modifications of the sensitivity of chemoreceptors responding to a drop in O₂ tension in the blood.     

EEG markers of the disturbed systemic brain activity in hypoxia

Specific rearrangements of the brain bioelectric potential field and the structures where the components (waves) of the main EEG rhythms interact, as well as the stereotactic location and power of the equivalent electrical dipole sources (EEDSs), were studied at various stages of acute experimental hypoxia (breathing for 15–30 min a hypoxic gas mixture containing 8% oxygen in nitrogen). The disrupted intercentral relationships that ensure the formation of the dynamic “morphological equivalent” to support the integrative brain activity, rearrangements of this activity, and the adaptive functions of the whole brain proved to account for partial or complete disintegration of systemic brain activity during acute hypoxia. EEDS tomography showed that EEDSs responsible for the generation of the basic brain rhythmic pattern are normally located in the thalamic structures. At the initial stages of hypoxia, the distribution of the EEDS foci is changed so that the density of EEDSs is increased on the sections that include the hypothalamic region structures, basal nuclei of the forebrain, and the limbic system; the basal, frontal, and medial regions of the temporal lobes of both hemispheres are also involved. With increasing hypoxia, EEDSs appeared in the basal and medial regions of the frontal lobes. At this time, both the surface and deep regions of the frontal lobes of the brain hemispheres are the major targets of the hypoxic effect. At the stages of severe hypoxia, pronounced functional changes in the CNS are observed, including the phenomenon of movement of multiple EEDS foci primarily through the basal and mediobasal regions of the frontal and temporal lobes and in the limbic system structures. Thus, despite the generalized high-amplitude paroxysmal activity that is observed in EEG, a functional disintegration (disruption) of interactions between individual brain regions appears and leads to disturbed regulation of the brain and systemic brain activity. Spatiotemporal EEG markers have been identified that make it possible to assess the individual sensitivity and resistance to hypoxia, as well as the degree of disintegration of his systemic brain activity at different stages of hypoxia.     

Effect of litonit and teturam on the course of biochemical processes in infectious inflammatory lesions of the kidneys in alcoholized animals

The time-course of changes in the activity of sorbitol dehydrogenase, catalase and the intensity of lipid peroxidation in the blood and kidneys of 250 albino rats was studied in the course of the development of alcoholic dependence when suffering from secondary infection. Litonit, a new antialcoholic drug, was found to be effective for the treatment of infectious inflammatory renal lesions in alcoholism. Unlike teturam, litonit promoted the decrease of sorbitol dehydrogenase and catalase activity in the kidneys and abated the intensity of lipid peroxidation. The possibility of using litonit as one of the remedies of pathogenetic therapy for infectious inflammatory renal lesions in alcoholism is under discussion.     

Effect of the constant magnetic field on the chemoluminescence of the skin during its destruction

A study was carried out of the effect of constant magnetic field of magnitophore applicator ALM-2 (CMFMA) with magnetic induction B on the surface, in the active centre zone--30 MT and gradient B--5 mT/mm on the intensity of peroxidation of lipids in the human skin during its destruction and under hypothermia. Parameters of ultralow chemoluminescence of skin homogenates initiated by bivalent iron ions were considered as intensity indices of lipid peroxidation. It has been shown that skin incubation for 24 hours under CMFMA effect rules out the strengthening of lipid peroxidation, while it takes place at skin incubation under normal conditions.     

Antioxidant enzyme activities,lipid peroxidation,and DNA oxidative damage: the effects of short-term voluntary wheel running

We examined the effect of voluntary exercise on antioxidant enzyme activities (catalase, glutathione peroxidase, superoxide dismutase) in skeletal muscle (hind- and forelimb) and heart of a model small mammal species: short-tailed field vole Microtus agrestis. In addition, DNA oxidation was determined in lymphocytes and hepatocytes using the comet assay and lipid peroxidation estimated in hindlimb muscle by measurement of thiobarbituric-acid-reactive substances. Voles (approximately 6 weeks old), exposed to a 16L:8D photoperiod (lights on 0500 h), ran almost continuously during darkness. We studied the effects of voluntary running over 1 or 7 days duration, with or without an 8-h rest period, on various biomarkers of oxidative stress compared to nonrunning controls. No differences were observed in antioxidant enzyme activities, except in heart total superoxide dismutase activity (P=0.037), with the lowest levels in 1- and 7-day runners at 0500 h. DNA oxidative damage, in lymphocytes or hepatocytes, and lipid peroxidation did not differ between groups. There was no evidence of any significant increase in any oxidative stress parameter in running individuals, despite having significantly elevated energy expenditures compared to sedentary controls.     

Opposite effects on antioxidant enzymes of adaptation to continuous and intermittent hypoxia]

Adaptation to continuous hypoxia under mid-mountain conditions (altitude 2100 m) decreases the content of lipid peroxidation products and the activity of superoxide dismutase and catalase in rat heart, liver, and brain, with a concomitant decline in the resistance to reperfusion arrhythmias. On the contrary, adaptation to intermittent hypoxia in the altitude chamber increases the activity of the antioxidant enzymes in the same organs, while the content of peroxidation products remains normal; at the same time, the heart becomes more resistant to reperfusion arrhythmias. The mechanism is discussed that ensures enhanced antioxidant protection in adaptation to intermittent hypoxia.     

Interaction of ferric complexes with rat liver nuclei to catalyze NADH-and NADPH-Dependent production of oxygen radicals

The production of potent oxygen radicals by microsomal reaction systems has been well characterized. Relatively little attention has been paid to generation of oxygen radicals by liver nuclei, or to the interaction of nuclei with different ferric complexes to catalyze NADH- or NADPH-dependent production of reactive oxygen intermediates. Intact rat liver nuclei were capable of catalyzing an iron-dependent production of .OH as reflected by the oxidation of .OH scavenging agents such as 2-keto-4-thiomethylbutyrate, dimethyl sulfoxide, and t-butyl alcohol. Inhibition of .OH production by catalase implicates H2O2 as the precursor of .OH generated by the nuclei, whereas superoxide dismutase had only a partially inhibitory effect. The production of .OH with either cofactor was striking increased by addition of ferric-EDTA or ferric-diethylenetriamine-pentaacetic acid (DTPA) whereas ferric-ATP and ferric-citrate were not effective catalysts. All these ferric complexes were reduced by the nuclei in the presence of either NADPH or NADH. The pattern of iron chelate effectiveness in catalyzing lipid peroxidation by nuclei was opposite to that of .OH production; with either NADH or NADPH, nuclear lipid peroxidation was increased by the addition of ferric ammonium sulfate, ferric-ATP, or ferric-citrate, but not by ferric-EDTA or ferric-DTPA. NADPH-dependent nuclear lipid peroxidation was insensitive to catalase, superoxide dismutase, or .OH scavengers; the NADH-dependent reaction showed a partial sensitivity (30 to 40%) to these additions. The overall patterns of .OH production and lipid peroxidation by the nuclei are similar to those shown by microsomes, e.g., effect of ferric complexes, sensitivity to antioxidants; however, rates with the nuclei are less than 20% those of microsomes, which reflect the lower activities of NADPH- and NADH-cytochrome c reductase in the nuclei. The potential for nuclei to reduce ferric complexes and catalyze production of .OH-like species may play a role in the susceptibility of the genetic material to oxidative damage under certain conditions since such radicals would be produced site-directed and not exposed to cellular antioxidants.     

Age-related peculiarities of antioxidant system functioning in the blood of ostriches

The intensity of lipid peroxidation, activity of some enzymes antioxidant system - superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione-S-transferase, amount of recovered glutathione and ceruloplasmin in the blood serum of ostriches in a period from 6- to 60-month age were first investigated. The increase of concentration of lipid peroxidation products is accompanied by the decline of amount of general lipids in the ostriches blood. Every life cycle period of ostriches is characterized by the indexes of functioning of the antioxidant system and intensity of accumulation intermediate lipid peroxidation products inherent in it. The pubescence period and intensive oviposition are characterized by the increase of products lipid peroxidation concentration and decrease of antioxidant enzymes activity, which can testify to the exhaustion of protective possibilities of enzymatic link of antioxidant defence.     

Effect of MPTP and l-Deprenyl on Antioxidant Enzymes and Lipid Peroxidation Levels in Mouse Brain

Abstract: Excessive free radical formation or antioxidant enzyme deficiency can result in oxidative stress, a mechanism proposed in the toxicity of MPTP and in the etiology of Parkinson's disease (PD). However, it is unclear if altered antioxidant enzyme activity is sufficient to increase lipid peroxidation in PD. We therefore investigated if MPTP can alter the activity of the antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-PX) and the level of lipid peroxidation. l -Deprenyl, prior to MPTP administration, is used to inhibit MPP⁺ formation and its subsequent effect on antioxidant enzymes. MPTP induced a threefold increase in SOD activity in the striatum of C57BL/6 mice. No parallel increase in GSH-PX or CAT activities was observed, while striatal lipid peroxidation decreased. At the level of the substantia nigra (SN), even though increases in CAT activity and reduction in SOD and GSH-PX activities were detected, lipid peroxidation was not altered. Interestingly, l -deprenyl induced similar changes in antioxidant enzymes and lipid peroxidation levels, as did MPTP. Taken together, these results suggest that an alteration in SOD activity, without compensatory increases in CAT or GSH-PX activities, is not sufficient to induce lipid peroxidation.     

Increased enzymatic activity of antioxidant protection of the heart in the adaptation of rats to short-term stress exposure

It has been shown that adaptation to short-term emotional-painful stresses leads to an increase in antioxidant enzyme activities but does not change vitamin E content in the myocardium. The most labile enzyme was catalase (35% increase). During stress in nonadapted animals the enzyme activity decreased, as compared to the control, while in the group of adapted animals with subsequent stress the activity was even higher than in the control. During initiation of lipid peroxidation in the heart homogenates in vitro there was a 3-fold increase and a 1%-fold decrease in the oxidation intensity in rats exposed to stress and in adapted animals, respectively. The role of adaptation activation of cardiac antioxidant system in the prevention of stress-induced heart damage is discussed.     

Role of a partially purified glutathione S-transferase from rat liver nuclei in the inhibition of nuclear lipid peroxidation

Glutathione protects isolated rat liver nuclei against lipid peroxidation by inducing a lag period prior to the onset of peroxidation. This GSH-dependent protection was abolished by exposing isolated nuclei to the glutathione S-transferase inhibitor S-octylglutathione. In incubations containing 0.2 mM S-octylglutathione, the GSH-induced lag period was reduced from 30 to 5 min. S-Octylglutathione (0.2 mM) also completely inhibited nuclear glutathione S-transferase activity and reduced glutathione peroxidase activity by 85%. About 70% of the glutathione S-transferase activity associated with isolated nuclei was solubilized with 0.3% Triton X-100. This solubilized glutathione S-transferase activity was partially purified by utilizing a S-hexylglutathione affinity column. The partially purified nuclear glutathione S-transferase exhibited glutathione peroxidase activity towards lipid hydroperoxides in solution. The data from the present study indicate that a glutathione S-transferase associated with the nucleus may contribute to glutathione-dependent protection of isolated nuclei against lipid peroxidation. Evidence was obtained which indicates that this enzyme is distinct from the microsomal glutathione S-transferase.     

Antioxidative enzymes in the liver and kidney of alloxan induced diabetic rats and their implications in cadmium toxicity

The influence of insulin-dependent diabetes mellitus on the oxidative stress caused by cadmium in the liver and kidney of laboratory rats has been studied. The results suggest that cadmium and alloxan diabetes independently promote lipid peroxidation in both liver and kidney. However, lipid peroxidation diminished in the diabetic rats fed cadmium. Administration of cadmium to normal and diabetic rats depleted glutathione in liver only. No significant change was observed in the activity of glutathione peroxidase in kidney, whereas administration of cadmium to diabetic rats stimulated catalase activity when compared to cadmium-fed rats. The actual mechanism of these effects still remains to be confirmed, but an antagonistic relationship between cytotoxic mechanisms of diabetes mellitus and cadmium is speculated upon. The insulin-dependent activity of a unique form of cytochrome 450j may be involved.     

Effect of dekaris and sodium nucleinate on the blood antioxidant system of guinea pigs exposed to paprin inhalation

The changes of lipid peroxidation, thiol disulfide equilibrium, glucoso-6-phosphate dehydrogenase, catalase and superoxide dismutase activity under influence of immunostimulants during paprin inhalation were studied. Pro-oxidant effect of dekaris has been established. The conclusion on the necessity to estimate the level of antioxidant system under immunocorrection has been made.