[Effect of conditioned-reflex bilateral avoidance learning on lipid components of the rat brain]. / Vliianie vyrabotki uslovnogo refleksa dvustoronnego izbeganiia na lipidnuiu komponentu mozga krys.

The active avoidance training of rats resulted in a depletion of lipid peroxidation (LPO) products in cerebral cortex. LPO inhibition was also shown in cerebral cortex of "active control" group receiving +non-combined stimuli (the effect of short-term stress). LPO inhibition was more pronounced in rats staining a training criterion compared to rats which received combined stimuli but did not reach the criterion. In the active control group LPO inhibition was accompanied by total phospholipids accumulation and cholesterol depletion in cortical lipid extracts. Irrespective of attaining the criterion in all rats trained for active avoidance the accumulation of cholesterol was seen. Active avoidance training affected also the phospholipid composition of cerebral cortex.

[The mechanism of superoxide dismutase functioning: a multicenter model]. / Mekhanizm funktsionirovaniia superoksiddismutazy: mnogotsentrovaia model'.

A new model of superoxide dismutase (SOD) functioning has been proposed on the basis of recent data. This model takes into account both experimental data and results of quantum mechanics calculations. One substrate molecule (superoxide radical) binds copper ion in active center of SOD, and the second superoxide radical interacts with a peripheral region of the enzyme. Uncoupled electron from the active center is transferred to the peripheral superoxide anion. This results in formation of oxygen molecule in the active center, and of hydrogen peroxide molecule in the peripheral region.

[Can the function of the extirpated amygdaloid complex be compensated for by the transplantation of embryonic nerve tissue?]. / Mozhno li kompensirovat' funktsiiu udalennogo mindalevidnogo kompleksa mozga putem transplantatsii émbrional'noi nervnoi tkani?

In 20 white rats bilateral coagulation of the amygdalar complex was produced; on the fifth day to one half of them transplantation was performed by introducing stereotaxically on the left side 0.2-0.5 mm3 of the brain embryonal tissue from the corresponding area of the amygdala of 20-days embryo; in control saline was administered. After two months the rats were sacrificed to determine the activity of antiradical defense by superoxide dismutase (SOD) and the level of lipids peroxide oxidation (LPO) in the cerebral cortex. The transplantation decreased LPO even more and increased SOD as compared to amygdalectomy, e. i. caused still greater deviations from the norm (in this meaning--paradoxal effect), what apparently corresponds to intensification of adaptative-compensatory processes caused by amygdalectomy. The transplantation did not reverse the rats behaviour to the initial one and did not eliminate memory defect in the test of conditioned reaction of passive avoidance (like pyrazetam); it had different direction influence on "drinking under current" in conflict situation, only in particular cases approaching it to the norm.

[Carnosine prevents the activation of free-radical lipid oxidation during stress]. / Karnozin predotvrashchaet aktivatsiiu svobodnoradikal'nogo okisleniia lipidov pri stresse.

Carnosine (beta-alanyl-L-histidine) injected to intact albino rats (20 mg/kg body weight) induces depletion of lipid peroxidation (LPO) products in brain and blood serum, an increase of superoxide scavenging activity in brain and serum, decrease of cholesterol: phospholipid ratio and increase of easy oxidizable phospholipid portion in brain lipid extracts. After painful stress (footshock during 2 hours) LPO products are accumulated in brain and serum, cholesterol: phospholipid ratio increases and the portion of easy oxidizable phospholipids decreases. Carnosine given before stress prevents LPO activation. Effects of carnosine and stress are not additive: LPO inhibition induced by carnosine is much more in rats subjected to stress.

[The effect of carnosine on indicators of free radical lipid oxidation during acute stress in rats]. / Vliianie karnozina na pokazateli svobodnoradikal'nogo okisleniia lipidov pri ostrom stresse u krys.

The effect of carnosine intraperitoneal injection in rats (in doses 0.2, 2.0 or 20 mg/kg) on the vegetative parameters (arterial blood pressure, Hildebrandt index), the content of free radical oxidation (FRO) products and superoxide dismutase activity in serum and brain homogenates and brain lipid composition under normal condition and after different stress forms have been investigated. The carnosine injection in dose 20 mg/kg preserves and increase in arterial pressure and Hildebrandt index at all steps of stress development. The phase non-unidirectional changes in studied biochemical parameters have been revealed depending on the level of stress development in animals under control. The unidirectional and dose-dependent changes of phospholipid content and the level of brain lipids, decrease of FRO products in tissue and brain cholesterol, the increase of the superoxide dismutase activity of serum and brain homogenates have been found in intact and stressed animals after carnosine injection. A comparison of carnosine pharmacokinetics with concentration dependences of the antioxidative effect under in vitro and in vivo experiments comes to conclusion concerning the carnosine indirect adaptogenic action.

[Antistress effects of vitamin E and dimethylsulfoxide during their combined administration in low doses]. / Antistressovye éffekty vitamina E i dimetilsul'foksida pri ikh sovmestnom primenenii v malykh dozakh.

Low doses of vitamin E (5 mg/kg body weight) and dimethyl sulfoxide (50 mg/kg) given simultaneously orally to albino rats prevented the disturbances of the behaviour and vegetative functions induced by chronic emotional painful stress. The adaptive effect of vitamin E or dimethyl sulfoxide given alone was much lower or altogether absent. The antioxidant combination used decreased the intensity of lipid peroxidation in the brain and blood serum as well as cholesterol content in brain lipids and activated brain superoxide dismutase and nonenzymatic superoxide scavenging activity of the serum. The results obtained suggest that the combination of vitamin E with dimethyl sulfoxide may be used for the treatment of pathological conditions accompanied by lipid peroxidation syndrome.

[Superoxide elimination activity and the transferrin-ceruloplasmin antioxidant system in the blood serum in chronic emotional-pain stress and the administration of dimethyl sulfoxide in rats]. / Superoksidustraniaiushchaia aktivnost' i antioksidantnaia sistema transferrin-tseruloplazmin v syvorotke krovi pri khronicheskom émotsional'no-bolevom stresse i vvedenii dimetilsul'foksida u krys.

The influence of emotional painful stress (EPS) and dimethyl sulfoxide (DMSO) treatment on ceruloplasmin-transferrin (Cp-Tr) antioxidant system and superoxide dismutase-like activity (SODLA) of the rat serum was studied. No changes in Cp-Tr and SODLA were observed in EPS. On the contrary, DMSO treatment was followed by a decrease in Cp-Tr activity and an increase in SODLA. It is suggested that Cp-Tr and SODLA systems are two interacting antioxidant systems of the serum.

[Indices of lipid free-radical oxidation and of antiradical protection of the brain--the neurochemical correlates of the development of the general adaptation syndrome]. / Pokazateli svobodnoradikal'nogo okisleniia lipidov i antiradikal'noi zashchity mozga--neirokhimicheskie korreliaty razvitiia obshchego adaptatsionnogo sindroma.

The stage of rat long-term adaptation to chronic emotional-pain stress is characterized by an increase of superoxide dismutase brain activity and superoxide-scavenging blood serum activity, accumulation of fluorescent products of free-radical oxidation, reduction of phospholipids and cholesterin contents in the brain lipid extracts. In the process of prolonged adaptation to the continuing chronic emotional-pain stress three periods are singled out, each of which with a definite correlation of characteristics of vegetative functions, behaviour, intensity of free-radical oxidation and antiradical defence.

[Apha-tocopherol in a complex with dimethyl sulfoxide--an agent possessing highly effective adaptogenic action in chronic emotional-pain stress in rats]. / Al'fa-tokoferol v komplekse s dimetilsul'foksidom--sredstvo, obladaiushchee vysokoéffektivnym adaptogennym deistviem pri khronicheskom émotsional'no-bolevom stresse u krys.

Alpha-tocopherol (5 mg/kg) administered perorally with dimethyl sulfoxide (50 mg/kg) in chronic emotional pain stress in rats possesses an effective antistress action, exceeding the effects of these drugs administered separately. Their prophylactic complex administration prevents the hypertension produced by stress, disturbance of reactivity of the vegetative nervous system during functional load, change of the behaviour in the open field. Adaptogenic action of the drugs is accompanied by a reduction of the content of free-radical oxidation products and by raising of superoxide scavenging activity in the brain and blood serum, by raising of phospholipids content, lowering of cholesterol content and of the ratio of cholesterol phospholipids in the brain extracts.

[Changes in superoxide dismutase activity in the presence of electron donors and acceptors]. / Izmenenie aktivnosti superoksiddismutazy pod deistviem donorov i aktseptorov élektronov.

The activity of superoxide dismutase (SOD) from bovine erythrocytes was measured by the inhibition of nitrotetrazolium blue reduction rate in superoxide anion radical generation systems--xanthine/xanthine oxidase of NADH/phenazine methasulfate. The enzyme activity increases in the presence of compounds acting as electron donors in radical-involving reactions and decreased in the presence of compounds possessing the properties of electron acceptors. Activation of SOD by electron donors and its inhibition by electron acceptors was dependent on the concentration of the above compounds. In the absence of SOD electron donors and acceptors did not change the rate of tetrazolium blue reduction by superoxide anion radicals. The role of the new type of SOD regulation for the enzyme functioning in the cell is discussed.

[Antistress effect of dimethyl sulfoxide in the rat]. / Antistressovyi éffekt dimetilsul'foksida u krys.

Administration of scavenger of hydroxyl radicals--dimethylsulfoxide (1 g/kg intraperitoneally, daily for 3 weeks) did not lead to any significant changes in animals behaviour in the open field and in visceral functions (arterial pressure, respiratory rate, heart rate) but prevented shifts of these characteristics caused by chronic 3-week emotional-pain stress. In rats injected with dimethylsulfoxide, an increase was observed of superoxide dismutase activity in the brain and blood serum. Molecular mechanisms are discussed of antistress action of dimethylsulfoxide (scavenge of hydroxyl radicals, activation of superoxide dismutase) and possible role of hydroxyl radicals in realization of damaging action of stress on the organism.

Modulation of superoxide dismutase by electron donors and acceptors.

The competition between superoxide dismutase (SOD) and nitroblue tetrazolium (NBT) for O2- radicals in the presence of a number of physiologically active compounds was studied. The Na+ channel blockers, ajmaline, tetracaine, bipuvacaine, lidocaine and etmozine produced an increase in the amount of O2- reacting with SOD. Nitroprusside, ferricyanide, BAY K8644, levomycetin, cGMP, cAMP and GMP acted in the opposite way. All the SOD activtors had in common the property of being electron donors in the reactions with the light-induced free radicals of eosin whereas the SOD inhibitors behaved as electron acceptors. The electron activity of SOD modulators correlated qualitatively with their regulating efficacy.

[Type of behavior and superoxide dismutase activity in the brain of rats (a comparison of 2 Tryon strains)]. / Tip povedeniia i aktivnost' superoksiddismutazy v golovnom mozge u krys (sravnenie dvukh linii Traiona).

Differences in the type of behaviour in capable ("maze-bright") and incapable ("maze-dull") Tryon rats have been demonstrated in the situation with pain-irritated partner by the method of "emotional resonance". Most "bright" rats belonged to the type not avoiding the signals of another pain-irritated rat, they revealed a persistent ecologically defensive reaction of preferring a small closed space. The type of anxiety behaviour prevailed in the group of "dull" rats. In the open field test "bright" rats were characterized by low locomotor activity and high level of defecation and "dull" rats by high activity and low defecation. Increased levels of superoxide dismutase activity and high content of thiobarbituric acid-reactive material were observed in brains of dull rats. The interrelations between behavioural and molecular levels of defensive response to stress is discussed.