[Effect of 6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline on the intensity of free radical processes and the activity of oxidative metabolism enzymes under toxic liver injury in rats]. / Vozdeistvie 6-gidroksi-2,2,4-trimetil-1,2-digidro-khinolina na intensivnost' svobodnoradikal'nykh protsessov i aktivnost' fermentov okislitel'nogo metabolizma pri toksicheskom porazhenii pecheni u krys.

The effect of 6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline on markers of hepatocytes cytolysis (aspartate aminotransferase, alanine aminotransferase and gamma-glutamyl transpeptidase), parameters reflecting the state of oxidative status (intensity of biochemical luminescence and the content of diene conjugates), and the activity of oxidative metabolism enzymes (aconitate hydratase, glucose-6-phosphate dehydrogenase, NADP-isocitrate dehydrogenase) was studied in rats with CCl4-induced liver injury. The results obtained in the course of the work demonstrated the ability of the test compound to reduce the severity of oxidative stress and liver cells damage, as well as to change the activity of aconitate hydratase and NADP-generating enzymes in the direction of control values. 6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline was more effective in normalizing CCl4-induced changes of the analyzed parameters that Carsil used as a reference compound. The tendency to normalize the state of oxidative status and enzyme activity of oxidative metabolism can attributed to hepatoprotective and antioxidant properties of the tested compound.

Activity of the glutathione antioxidant system and NADPH-generating enzymes in blood serum of rats with type 2 diabetes mellitus after administration of melatonin-correcting drugs.

We studied the effects of epifamin and melaxen on serum content of reduced glutathione and activities of glutathione peroxidase, glutathione reductase, and NADPH-generating enzymes (glucose-6-phosphate dehydrogenase and NADP-isocitrate dehydrogenase) in rats with type 2 diabetes mellitus. The concentration of reduced glutathione was decreased in rats with this disease (by 1.8 times), but increased after treatment with epifamin and melaxen (by 1.6 and 1.7 times, respectively). Activities of glutathione peroxidase, glutathione reductase, and NADPH-generating enzymes returned to the control level. Correction of melatonin concentration after treatment with the test drugs was probably followed by inhibition of free radical processes. The observed changes were accompanied by normalization of activity of the glutathione antioxidant system and NADPH-generating enzymes required for normal function of this system.

[Effect of melatonin on antioxidant state under type ii diabetes at rat].

The effect of melatonin on the intensity of free radical processes and activities of superoxide dismutase (SOD, EC 1.15.1.1.) and catalase (EC 1.11.1.6) has been investigated in liver and blood serum of rats with diabetes mellitus type II. The development of diabetes was accompanied by the increase in biochemiluminescence parameters and the enzyme activities studied. Melatonin administration changed the parameters studied towards control values.

Effect of 3,5-dicarbomethoxyphenylbiguanide on free radical homeostasis in rats with experimental myocarditis.

Administration of 3,5-dicarbomethoxyphenylbiguanide to rats with experimental epinephrine-induced myocarditis was followed by a decrease in activity of marker enzymes for cardiomyocyte cytolysis in the blood serum. This agent also decreased the intensity of free radical processes and had a normalizing effect on aconitase activity in the heart and blood serum of rats with myocarditis.

Effect of N-[Imino(4-morpholyl)methyl]guanidine on the oxidative status in rats with toxic hepatitis.

The hepatoprotective and antioxidant properties of a synthetic biguanide N-[imino(4-morpholyl)methyl]guanidine (IMMG) were prognosticated by the method of computer prediction. Administration of IMMG was accompanied by a decrease in serum transaminase activity in rats with toxic hepatitis, which reflects inhibition of hepatocyte cytolysis. IMMG treatment was followed by a decrease in biochemiluminescence parameters reflecting the intensity of free radical oxidation. We revealed an increase in activity of aconitase, which was reduced during toxic hepatitis. The content of citrate in the liver and serum was returned to normal under these conditions. IMMG also increased activities of superoxide dismutase and catalase and total antioxidant activity in rat liver. Our results suggest that the hepatoprotective effect of IMMG is associated with its antioxidant activity.

Aconitate hydratase of mammals under oxidative stress.

Data on the structure, functions, regulation of activity, and expression of cytosolic and mitochondrial aconitate hydratase isoenzymes of mammals are reviewed. The role of aconitate hydratase and structurally similar iron-regulatory protein in maintenance of homeostasis of cell iron is described. Information on modifications of the aconitate hydratase molecule and changes in expression under oxidative stress is generalized. The role of aconitate hydratase in the pathogenesis of some diseases is considered.

Effects of lipoic acid on citrate content, aconitate hydratase activity, and oxidative status during myocardial ischemia in rats.

The effects of lipoic acid on intensity of free radical reactions, citrate content, and aconitate hydratase during myocardial ischemia have been investigated. Treatment with lipoic acid normalized biochemiluminescence parameters and citrate level, which were increased in the myocardial pathology. Treatment with lipoic acid also increased specific activity of aconitate hydratase, which was decreased in myocardium and blood of animals with myocardial ischemia. Administration of lipoic acid decreased DNA fragmentation observed during myocardial ischemia. The data suggest that lipoic acid can be effectively used as a cardioprotector preventing the development of free radical oxidation during myocardial ischemia.

[Thioctic acid action on glutathione-dependent antioxidant system functioning at toxic hepatitis of rats].

The effect of thioctic acid on the glutathione dependent antioxidant system and activities of enzymes, generating NADPH of rats has been investigated in rats under conditions of toxic hepatitis. Injections of thioctic acid to animals with toxic hepatitis caused the decrease of glutathione reductase and peroxidase activities to the normal level. Reduced glutathione content also tended to the control level. Administration of thioctic acid to rats with toxic hepatitis also caused the decrease of NADP-dependent isocitrate dehydrogenase and glucose-6-phosphate dehydrogenase which might be associated with decreasing need of NADPH supply for glutathione dependent antioxidant system. Thus, obtained results have shown that thioctic acid may regulate manifestations of oxidative stress and the state of the glutathione antioxidant system.

[The intensity of free radical oxidation and catalytic properties of the rat liver NADP-isocitrate dehydrogenase in the norm and in toxic hepatitis].

Parameters of hepatic free radical oxidation and catalytic properties of NADP-isocitrate dehydrogenase (EC 1.1.1.42; NADP-IDH) have been investigated in normal rats and under conditions of toxic hepatitis. Development of hepatitis was accompanied by the increase of conjugated dienes, malondialdehyde and some chemiluminescence parameters. Toxic hepatitis was also accompanied by the increase of liver NADP-IDH. Homogenous preparations of liver NADP-IDH from normal and toxic rats exhibited different sensitivity to effectors studied (Fe2+, Ca2+, H2O2, reduced glutatione).

Function of cytoplasmic NAD-dependent malate dehydrogenase from rat myocardium under conditions of ischemia.

NAD-dependent malate dehydrogenase activity decreased by 2.7 times in the myocardium of rats with experimental ischemia. Cytoplasmic NAD-dependent malate dehydrogenase from intact and ischemic rat heart was purified by 91.4 and 95.5 times. We compared kinetic characteristics and regulation of enzyme activity by Fe(2+), Cu(2+), Ca(2+), hydrogen peroxide, and glutathione under normal and pathological conditions.