[Carnitine chloride reduces the severity of experimental hyperhomocysteinemia and promotes lactate utilization by mitochondrial fraction of the rat epididymis]. / Karnitina khlorid snizhaet stepen' vyrazhennosti éksperimental'noi gipergomotsisteinemii i sposobstvuet utilizatsii laktata mitokhondrial'noi fraktsiei épididimisa krys.

Hyperhomocysteinemia is a risk factor for many diseases, including reproductive disorders in men. L-carnitine is used in medical practice to correct impaired bioenergetic conditions; in patients with idiopathic forms of infertility its effects are associated with improvement of the sperm parameters. However, the effect of exogenous L-carnitine on the level of homocysteine in the gonadal tissues, as a risk factor for impaired fertility, has not been investigated yet. The aim of this study was to investigate activity of bioenergetic enzymes in the epididymal mitochondrial fraction, the dynamics of changes in the cytoplasmic and mitochondrial lactate levels and LDH activity, the total carnitine content, as well as the oxidative status of these cells under conditions of oxidative stress caused by hyperhomocysteinemia, and to assess the effect of carnitine chloride on these parameters under conditions of methionine administration to male Wistar rats. Methionine administration to animals for three weeks at a dose of 3 g/kg, resulted in development of the severe forms of hyperhomocysteinemia with serum homocysteine concentrations exceeding 100 µmol/L. This was accompanied by a decrease in the activity of enzymes involved in the bioenergetic processes of the cell: tissue respiration (succinate dehydrogenase) and oxidative phosphorylation (H+-ATPase) in the epididymal head and tail. The change in lactate metabolism included an increase in its level in both the mitochondrial and cytoplasmic fractions of the epididymal head and mitochondria of the epididymal tail, and also simultaneous statistically significant decrease in LDH activity in the mitochondria and cytoplasm of the epididymal head. In male rats with severe hyperhomocysteinemia, an increase in the activity of mitochondrial SOD accompanied by an increase in the carbonylation of mitochondrial proteins in the head and tail of the epididymis was noted. Modeling of hyperhomocysteinemia under conditions of carnitine chloride of administration led to different reactions of the cells of the studied tissues assayed in the epididymal head and tail homogenate. In the epididymal head, carnitine chloride promoted an increase in the mitochondrial lactate concentration and a decrease in the cytoplasmic lactate concentration, as well as an increase in the LDH activity associated with the mitochondrial fraction. These changes were accompanied by an increase in the activity of H+-ATPase in the epididymal, thus suggesting that carnitine chloride stimulated lactate transport of into the mitochondria and its use as an energy substrate under conditions of oxidative stress caused by hyperhomocysteinemia. In the tail tissues, the changes were protective in nature and were associated with a decrease in the formation of oxidatively modified proteins.

[Endotheliotropic effects of venotonic drugs in treatment of patients with varicose veins]. / Éndoteliotropnye éffekty venotoniziruiushchikh preparatov pri lechenii bol'nykh s varikoznoi bolezn'iu.

The authors analysed the effect of Venarus on the endothelial function in patients suffering from lower limb varicose veins. Our open-label prospective study included a total of 100 patients diagnosed as having CEAP class C1-C2 varicose veins and divided into two equal groups. Dynamic assessment of the clinical course of the disease in Group One patients was carried out on the background of taking Venarus and compression therapy, with Group Two patients evaluated without taking Venarus. At defined stages we determined the level of biochemical markers of endothelial function. The obtained findings demonstrated that the use of phlebotonic Venarus resulted in decreased activity of lipid peroxidation processes and reduced activity of antioxidant system enzymes. Using Venarus was followed by a statistically significant decrease in the concentration of malonic dialdehyde (from 1.220±0.190 µmol/l at baseline to 0.858±0.231 µmol/l after 2 months of treatment), whereas in Group Two patients the changes were insignificant (1.191±0.204 µmol/l before treatment and 1.138±0.175 µmol/l at 2 months thereafter). Patients taking Venarus were also found to have a higher level of nitric oxide metabolites compared with the patients treated by compression therapy alone (51.646±11.757 and 36.310±6.921 µmol/l in Groups One and Two, respectively). Hence, an evidence-based conclusion was drawn that Venarus proved efficient and may therefore be prescribed as pharmacotherapy for correction of endothelial dysfunction.

[Metabolic changes in pulmonary mitochondria of rats with experimental hyperhomocysteinemia]. / Metabolicheskie izmeneniia v mitokhondriiakh legkikh pri éksperimental'noi gipergomotsisteinemii u krys.

Hyperhomocysteinemia is a risk factor for many human diseases, including pulmonary pathologies. In this context much interest attracts secondary mitochondrial dysfunction, which is an important link in pathogenesis of diseases associated with hyperhomocysteinemia. The study was conducted using male Wistar rats. It was found that under conditions of severe hyperhomocysteinemia caused by administration of methionine, homocysteine was accumulated in lung mitochondria thus suggesting a direct toxic effect on these organelles. However, we have not observed any significant changes in the activity of mitochondrial enzymes involved in tissue respiration (succinate dehydrogenase) and oxidative phosphorylation (H+-ATPase) and of cytoplasmic lactate dehydrogenase. Also there was no accumulation of lactic acid in the cytoplasm. Animals with severe hyperhomocysteinemia had higher levels of lung mitochondrial protein carbonylation, decreased reserve-adaptive capacity, and increased superoxide dismutase activity. These results indicate that severe hyperhomocysteinemia causes development of oxidative stress in lung mitochondria, which is compensated by activation of antioxidant protection. These changes were accompanied by a decrease in the concentration of mitochondrial nitric oxide metabolites. Introduction to animals a nonselective NO-synthase inhibitor L-NAME caused similar enhancement of mitochondrial protein carbonylation. It demonstrates importance of reducing bioavailability of nitric oxide, which is an antioxidant in physiological concentrations, in the development of oxidative stress in lung mitochondria during hyperhomocysteinemia. Key words: hyperhomocysteinemia, nitric oxide, lung, oxidative stress, mitochondria.

[The study of biochemical mechanisms of mitochondrial dysfunction in rats' hepatocytes during experimental hyperhomocysteinemia].

Methionine is an essential proteinogenic amino acid found in many foods. During its metabolism homocysteine is formed. With elevated level of homocysteine in the blood--hyperhomocysteinemia--increased risk of developing certain diseases, such as non-alcoholic fatty liver disease, is associated. There is evidence that the homocysteine is able to reduce the effect of nitric oxide and induce mitochondrial dysfunction. The present study investigates the relationship of the functional state of the liver cells mitochondria and the level of nitric oxide metabolites in them in experimental hyperhomocysteinemia caused by excessive intake of methionine. The experiment was conducted on 17 male Wistar rats with an initial weight of 220-270 g, rats were divided into 2 groups. A 25%. suspension of methionine was administered (in a dose of 1.5 g of methionine per kg body weight) two times a day for 21 days intragastrically (by gavage) to rats of the first group (n=9) while instead of drinking water animals received a 1% aqueous solution of methionine. Drinks daily volume of methionine solution was 17.2 [15.5; 18.1] ml. In the experiment 8 animals were used, in which severe hyperhomocysteinemia (> 100 mmol/l) was developed. The second group (n = 8) served as a control. These rats were administered suspension base containing no methionine (10% Tween-80, 1% starch, 89% water). The total homocysteine concentration was measured in blood serum by ELISA. In the suspension of liver mitochondria total protein was measured by Lowry method; the concentration of NO metabolites by screening method; succinate dehydrogenase activity--under the reaction of hexacyanoferrate (III) potassium reduction; lactate dehydrogenase activity--by decrease of NADH concentration in the reaction of pyruvate's reduction; activity of H(+)-ATPase--by measuring the inorganic phosphate; superoxide dismutase--by inhibition of quercetin auto-oxidation, the level of Ca(2+)--by reaction with Arsenazo III. Oxidative modification of proteins was evaluated based on the reaction between carbonyl and imino groups of the amino acid residues oxidized with 2,4-dinitrophenylhydrazine to form 2,4-dinitrophenylhydrazone having a specific absorption spectrum in the ultraviolet and visible regions of the spectrum. During three weeks of the experiment the body weight of rats treated with methionine increased from 246 (229; 262) to 302 (283; 311) g, and of control animals--from 256 (231; 264) to 307 (275; 314) g. The difference in body weight gain was not statistically significant. In the study it was revealed that intragastric administration of the methionine for 3 weeks with the addition of this amino acid in the drinking water caused hyperhomocysteinemia. On the one hand it lead to an intensification of energy metabolism in rat liver mitochondria, resulted in increase of lactate dehydrogenase (by 63.0%), succinate dehydrogenase (by 76.1%) and H(+) -ATPase (by 62.5%) activities. On the other hand it lead to the disruption of the Ca2+ deposit (Ca2+ level in mitochondria was reduced by 68.2%) and to enhance of mitochondrial protein carbonylation (by 52.2%) with a predominance of the aggregation process and a reduction of the reserve-adaptive capacity, despite an increase in superoxide dismutase activity (by 87.7%). The reason for these changes in the mitochondria can be the decrease in production of nitric oxide (the level of its metabolites decreased by 21.3%).