[Comparative evaluation of the antiradical and antioxidant activity of estrogens and their nitro derivatives]. / Sravnitel'naia otsenka antiradikal'noi i antioksidantnoi aktivnosti éstrogenov i ikh nitroproizvodnykh.

Estradiol, ethynylestradiol, and estradiol acetate possess antiradical activity (K7 = (1.8-2.0) x 10(-4) liter/mole sec). Nistranol exhibits antiradical properties only upon acid hydrolysis. The results of experiments with egg yolk liposomes showed evidence of a pronounced antioxidant activity of estradiol, ethynylestradiol, and estradiol nitrate, and the absence of such activity in nistranol. In the experiments on rat heart homogenates, nitroestrogens in a concentration of about 10(-4) M reduced the level of TBA-active products.

[The effect of calcium antagonists on blood deoxygenation processes]. / Vliianie antagonistov kal'tsiia na protsessy deoksigenatsii krovi.

The effect of verapamil, nifedipine and sensit on the whole rat blood deoxygenation was studied by polarographic coulometry with consequent calculation of deoxygenation rate (DR) and blood deoxygenation constant (BDC). These drugs were studied in concentrations 10(-8)-10(-4) M according to their therapeutic range in vivo. Both verapamil and nifedipine significantly decreased DR, and the latter drug decreased BDC as well in concentration 2.9.10(-7) M. In contrast to verapamil and nifedipine, sensit caused mild, but statistically significant dose-related increase in DR with concomitant decrease in BDC. The data presented failed to establish relationships between chemical structure and deoxygenative effect of the drugs. Deoxygenation effect of sensit favours its administration in the treatment of ischemia-related arrhythmias.

[State of the free-radical oxidation system in normobaric hypoxia]. / Sostoianie sistemy svobodnoradikalnogo okisleniia pri deistvii normobaricheskoi gipoksii.

The experiments on the rats have revealed that 7-hour action of 10% hypoxic gas mixture (HGM-10) exerts no effect on the parameters of Fe(2+)-induced chemiluminescence and rate of accumulation of TBA-active products in the heart, liver, kidney, brain tissues and blood plasma. Two-week adaptation to intermittent effect of HGM-10 causes some activation of free-radical oxidation recorded in blood plasma and the more pronounced increase in power of the endogenic antioxidant system. It is assumed that the revealed changes in the state of the homeostatic system of free-radical oxidation and antiradical protection of the organism are of importance in the mechanism of the known preventive and curative action of intermittent normobaric hypoxia.

[The radioprotective and antioxidant properties of solubilized alpha-tocopherol acetate]. / Radiozashchitnye i antioksidantnye svoistva soliubilizirovannogo al'fa-tokoferola atsetata.

A single intravenous administration of solubilized alpha-tocopherol acetate in a dose of 1 mg/kg to CBA x C57Bl x F1 male mice 3 and 24 hours before radiation was demonstrated to increase 30-day survival rates in the animals. Oily alpha-tocopherol acetate had the identical effects when the agent was intramuscularly given in a dose of 10 mg/kg. There was a rise in peripheral leukocyte counts 0.5 hour after solubilized alpha-tocopherol acetate administration. The antioxidative activity of the solubilized agent was 3.3 times as high as that the routine agent when attacking Tween 80. The higher radioprotective activity of solubilized alpha-tocopherol acetate is accounted for by its enhanced bioavailability, antioxidative activity and effects on the factors of nonspecific body's resistance.

[The effect of antioxidants on the fast burst of Fe2(+)-induced chemiluminescence]. / Vliianie antioksidantov na bystruiu vspyshku Fe2()-indutsirovannoi khemiliuminestsentsii.

A new micromethod for measuring the intensity of free radical oxidation reactions, based on an analysis of "fast flash" of iron-induced chemiluminescence parameters has been designed. The optimal concentration parameters of the reaction system have been determined. The effects of the antioxidants mexidol, probucol sodium dibunat and fenoxan have been examined in vitro.

[Effects of extreme factors and antioxidant alpha-tocopherol on the intensity of blood plasma chemiluminescence]. / Vliianie ékstremal'nykh vozdeistvii i antioksidanta alfa-tokoferola na intensivnost' khemiliuminestsentsii plazmy krovi.

It was established in experiments on rats that intensity of "fast flash" of iron-induced chemiluminescence of biological samples containing microvolumes of blood plasma correlate with resistance of organism to severe hypoxia. The new method is promising for the estimation of the sensitivity of intact organism to severe hypoxia, for registration of antioxidant therapy effects and for studying the mechanisms of extreme factors influence on the organism.

[Relationship of antioxidant and anti-ischemic effects of various energy-yielding compounds]. / Sootnoshenie antioksidantnogo i protivo-ishemicheskogo éffekt nekotorykh énergoobespechivaiushchikh sredstv.

Influence of fructose++-1,6-diphosphate, succinate, malate and cytochrome C on free lipid peroxidation (FLP), infarct sizes and metabolic acidosis was studied in experiments on rats. The good correlation between inhibition of FLP and cardioprotector activity was established for activators of glycolytic energy production only. Krebs' cycle metabolites limited the zone of myocardial necrosis after coronary occlusion without any significant depression of FLP. Succinate and malate were practically inactive under acute metabolic acidosis of isolated rat heart.

[The role of hyperoxidation in changes of lipid peroxidation and tissue metabolism in patients undergoing surgery with artificial circulation]. / Rol' giperoksii v izmenenii perekisnogo okisleniia lipidov i tkanevogo metabolizma u bol'nykh, operirovannykh v usloviiakh iskusstvennogo krovoobrashcheniia.

53 patients with various heart diseases subject to cardiopulmonary bypass surgery have been examined. To assess the state of tissue metabolism indexes of arterial and mixed venous blood oxygen balance, lactate concentration, the activity of energy-dependent lymphocyte enzymes and indexes of free-radical plasma processes have been studied. It has been shown that cardiopulmonary bypass in conditions of marked normobaric hyperoxidation (PaO2 more than 300 mm Hg) is accompanied by tissue metabolism intensification and disturbance. Inability of protective antioxidant mechanisms to react to the intensity of free-radical formation due probably both to surgical stress and cardiopulmonary bypass procedure performed in hypothermia leads to negative hyperoxidation effect on metabolism even in conditions of adequate perfusion. A relatively high dependence of the frequency of myocardial depression on the degree of hyperoxidation suggests that myocardial reperfusion by blood with high PaO2 upon anoxic arrest is advisable in hypothermic cardiopulmonary bypass with attenuated activity of the antioxidant systems protecting cells from oxygen free radicals.

[Comparison of the antioxidative activity of fenibut, fentolamin and ionol]. / Sravnitel'naia antiokislitel'naia aktivnost' fenibuta, fentolamina i ionola.

Phenibut and phentolamine were found to exhibit the properties of the true antioxidants in the hen egg yolk suspension and in the rat brain homogenate. The antioxidative activities of the drugs were significantly higher in the brain homogenate, while the antioxidative activity of the known antioxidant ionol was unchanged.

[Action of obzidan and isoptin on the indices of free-radical lipid peroxidation of the ischemic myocardium]. / Deistvie obzidana i izoptina na pokazateli perekisnogo svobodnoradikal'nogo okisleniia lipidov ishemizirovannogo miokarda.

Effects of obsidan and isoptine on Fe2+-induced free radical lipid peroxidation (FRLP) were studied according to the data of chemoluminiscence (CL) and malon dialdehyde (MDA) content during experiments on the intact myocardium and at two-thour ischemia of the myocardium as well in the suspension of egg yolk lipoproteids. It was found that in the intact myocardium obsidan (10% LD50) suppressed FRLP according to the CL data, simultaneously increasing MDA level, and in the ischemic myocardium significantly suppressed FRLP by a number of parameters. Isoptine in the intact myocardium exerted no effect on CL with a simultaneous increase of MDA level, and in the ischemic myocardium suppressed FRLP by most parameters. In the suspension of egg yolk lipoproteids obsidan and isoptine changed MDA concentration in a two-phase manner. Isoptine also had a two-phase action on FRLP according to the CL data. A high antioxidative activity of obsidan in the suspension of egg yolk lipoproteids was noted as compared to that of isoptine. Based on the data of kinetics of Fe2+-induced CL in the suspension of egg yolk lipoproteids, obsidan is a true antioxidant by its mechanism of action and ispoptine is a structural antioxidant.

[Characteristics of the antihypoxic action of piracetam]. / Osobennosti protivogipoksicheskogo deistviia piratsetama.

Pyracetam was found to inhibit free-radical lipid peroxidation, slow oxygen consumption in the liver mitochondria and increase hemoglobin oxygen-binding properties. It is assumed that the ability of pyracetam to inhibit lipid peroxidation is a mechanism which determines its antihypoxic effect.

[Effect of methyluracil on lipid peroxidation in the plasma and tissue homogenates from ulcer lesions of the gastric wall in rats]. / Vliianie metiluratsila na perekisnoe okislenie lipidov v plazme krovi i gomogenatakh tkanei iazvennogo defekta stenki zheludka krys.

Dynamics of experimental acetate gastric ulcer healing and lipid peroxidation were studied in rat blood and gastric tissues after treatment with methyluracil. The drug was shown to stimulate reparation and to inhibit lipid peroxidation. The antiulcerogenous effects of methyluracil appear to involve the antioxidative mechanisms.

[Characteristics of the chemiluminescence of the system containing H202 in the presence of iron compounds]. / Osobennosti khemiliuminestsentsii sistemy, soderzhashchei H202 v prisutstvii soedinenii zheleza.

The relative effectiveness of radical formation by different concentrations of hemoglobin, hemin and Fe2+ in the reaction with H2O2 evaluated by the intensity of chemiluminescence was studied. Hemoglobin was shown to be remarkably effective at the concentrations close to those in blood plasma. It is suggested that exoerythrocyte hemoglobin and the products of its destruction up to hemin are the most effective prooxidants and potential centers of radical formation in the blood.

[Effect of acetylcholine, cholinomimetics, cholinolytics and dipiroxim on the chemiluminescence of a model system of peroxidation]. / Vliianie atsetilkholina, nekotorykh kholinomimetikov, kholinolitikov i dipiroksima na khemiliuminestsentsiiu model'noi sistemy perekisnogo okisleniia.

Use was made of a model system initiating lipid peroxidation, that contained phosphate buffer, H2O2 and eosine. Chemiluminescence of the system decreased after addition to rat brain synaptosomes, thereby indicating the presence of antioxidants in the animals' brain. After addition of brain synaptosomes of rats poisoned with high lethal doses of armine (0.4--0.5 mg/kg) a prooxidant effect was observed. It was manifested in the elimination of the effect of natural antioxidants contained by synaptosomes of normal rats. Addition of acetylcholine, armine, DFP and oxazyl at concentrations of 1.10(-4) 1.10(-3) M to the model system containing rat brain synaptosomes entailed a considerable intensification of chemiluminescence. Atropine and scopolamine did not produce any substantial effect on chemiluminescence, whereas dipiroxim exerted an overt antioxidant effect. The conclusion is made about the possibility of activating the system of lipid peroxidation as one of the components of the toxic action of anticholinesterase agents.

[Information value of different blood serum chemiluminescence indices in acute myocardial infarct]. / Informativnaia tsennost' razlichnykh pokazatelei khemiliuminestsentsii syvorotki krovi bol'nykh ostrym infarktom miokarda.

The study of informativeness of varying parameters of induced chemifluorescence reflecting the intensity of free-radical oxygenation of lipids and their dependence on the degree of necrotic damage of the myocardium, determined by the activity of creatine phosphokinase and its cardiospecific isoenzyme MB. 19 patients and 20 healthy individuals were examined. The results show that inhibition of induced chemifluorescence of the blood serum in the period of developing necrotic changes is directly dependent on the content of products of the ischaemic destruction of the myocardium.