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Biomedical subjects

V Z Lankin

Publications and source records attributed to V Z Lankin.

At least 37 records · Page 2Linked to original sources
PubMed2002

Oxidative stress in patients with primary pulmonary hypertension.

We studied the role of oxidative stress in the pathogenesis of primary pulmonary hypertension. In patients with primary pulmonary hypertension the content of malonic dialdehyde in the plasma was higher than in healthy volunteers (5.18 0.46 and 2.95 0.14 nmol/liter, respectively, p<0.01). However, glutathione peroxidase activity in the plasma decreased in these patients (0.50 0.17 vs. 1.19 0.14 U/ml in the control, p<0.05). By contrast, glutathione peroxidase activity in erythrocytes from patients surpassed the control (6.13 0.39 and 4.63 0.45 U/h hemoglobin). The increase in malonic dialdehyde content in the plasma and glutathione peroxidase activity in erythrocytes and the decrease in glutathione peroxidase activity in the plasma were most pronounced in patients with severe cardiac insufficiency and pulmonary hypertension. Our results indicate that antioxidant preparations improve the prognosis in patients with primary pulmonary hypertension.

Adolescent↗
PubMed2002

Intensification of free radical oxidation of low-density lipoproteins in the plasma of patients with ischemic heart disease receiving beta-hydroxy-beta-methylglutaryl-coenzyme A reductase inhibitor cerivastatin and inhibition of low-density lipoprotein peroxidation with antioxidant probucol.

Inhibitors of the key enzyme of cholesterol biosynthesis beta-hydroxy-beta-methylglutaryl-coenzyme A reductase (statins) decrease cholesterol content in atherogenic low-density lipoproteins in patients with coronary heart disease and hypercholesterolemia, but inhibited biosynthesis of ubiquinone Q10 protecting low-density lipoproteins from free radical oxidation. Cerivastatin in a daily dose of 0.4 mg markedly increased the content of lipid peroxides in low-density lipoproteins. However, complex therapy with cerivastatin and antioxidant probucol (250 mg/day) was accompanied by a sharp decrease in the content of lipid peroxides in low-density lipoproteins in patients with coronary heart disease in vivo. These data indicate that antioxidant agents should be used in combination with inhibitors of beta-hydroxy-beta-methylglutaryl-coenzyme A reductase (hypolipidemic preparations) for the therapy of patients with coronary heart disease.

Antioxidants↗
PubMed2001

Antioxidant systems in tissues of senescence accelerated mice.

Significant decrease in the level of lipid antioxidants (measured from the kinetics of the induced chemiluminescence in brain homogenate) and of the hydrophilic antioxidant carnosine as well was observed in the brain of 14-16-month-old mice of SAMP1 line, which is characterized by accelerated accumulation of senile features, in comparison with the control line SAMR1. In the brain of SAMP1 animals the activity of cytosolic Cu/Zn-containing superoxide dismutase (SOD) was reduced, while the activity of membrane-bound Mn-SOD was at an extremely low level. The activity of glutathione-dependent enzymes (glutathione peroxidase, glutathione reductase, and glutathione transferase) did not differ in the brain of SAMP1 and SAMR1 animals, and catalase activity was similarly low in both cases. At the same time, excess concentration of excitotoxic compounds, significantly exceeding that for the control line, was determined in the brain and blood of SAMP1 animals. The activity of glutathione enzymes in liver and heart as well as the activity of cytosolic Cu/Zn-SOD in liver did not differ in the two studied lines, while the activity of erythrocyte glutathione peroxidase was slightly increased, and the activity of liver catalase and erythrocyte Cu/Zn-SOD was significantly decreased for SAMP1 compared with SAMR1. The results demonstrate that the accelerated ageing of SAMP1 animals is connected to a significant extent with the decreased efficiency of the systems utilizing reactive oxygen species (ROS) in tissues.

Aging↗
PubMed2001

Inhibitor of beta-hydroxy-beta-methylglutaryl coenzyme A reductase decreases energy supply to the myocardium in rats.

Hypocholesterolemic preparations, inhibitors of the key enzyme of cholesterol biosynthesis beta-hydroxy-beta-methylglutaryl coenzyme A reductase (statins), block the synthesis of ubiquinone Q10, intermediate electron carrier in the mitochondrial respiratory chain. This should decrease energy supply to tissues. Daily peroral administration of beta-hydroxy-beta-methylglutaryl coenzyme A reductase inhibitor simvastatin (24 mg/kg perorally) for 30 days had no effect on the contents of macroergic phosphates (ATP and creatine phosphate) in the liver, but decreased these parameters in the myocardium.

Adenosine Diphosphate↗
PubMed2001

Free radical lipid peroxidation inhibits enzymatic conversion of beta-carotene into vitamin A.

Free radical oxidation of arachidonic acid with soybean lipoxygenase was accompanied by inhibition of retinal synthesis from beta-carotene catalyzed by enzyme preparation from rabbit intestinal mucosa. Lipoxygenase inhibitor salicylhydroxamic acid and antioxidants suppressing free radical reactions (ethyl gallate, alpha-tocopherol, astaxanthine, and quercetin) promoted conversion of beta-carotene into retinal catalyzed by beta-carotene-15,15'-dioxygenase. These results indicate that lipoperoxides and/or products of their homolysis attenuate enzymatic conversion of beta-carotene and confirm the important role of natural antioxidants in the maintenance of stable vitamin A content in mammals.

Animals↗
PubMed2000

Antioxidant activity of parapharmaceutics containing natural inhibitors of free radical processes.

The duration of lag phase of ascorbate-dependent free radical oxidation of endogenous polyenic lipids in rat liver and myocardium considerably increased after oral administration of lacrinat containing licorice Glycyrrhiza glabra root powder for 1 month. Lacrinat markedly decreased the content of lipid peroxides in rat liver. Ex vivo antioxidant effects of lacrinat in rat liver were comparable with those of beta-carotene-containing preparations carinat and carinat CD. Parapharmaceutics containing both licorice Glycyrrhiza glabra root powder and beta-carotene (carinat forte) markedly increased antioxidant activity of the liver.

Animals↗
PubMed2000

Beta-carotene-containing preparation carinat inhibits lipid peroxidation and development of renal tumors in rats treated with chemical carcinogen.

The effects of pretreatment with beta-carotene-containing preparation carinat on the development of renal tumors in rats receiving single intravenous injection of chemical carcinogen 3-(1-alpha-L-arabinopyranosyl)-1-methyl-1-nitrosourea were studied. Fourteen months after carcinogen administration, the degree of lipid oxidation in rat kidneys 2.5-fold surpassed that in animals receiving carinat in a dose producing in vivo antioxidant effect. Carinat decreased the total number of induced tumors and the incidence of mesenchymal renal tumors and suppressed the development of multiple tumors. The accumulation of lipoperoxides in the kidneys during carcinogenesis is associated with activation of free radical processes and carcinogen-induced inhibition of lipoperoxide enzymatic degradation and probably promotes renal malignancies due to co-carcinogenic action of these compounds. The data suggest that carinat-induced suppression of tumor development attests to antioxidant effects of beta-carotene.

Animals↗
PubMed2000

Trimetazidine as indirect antioxidant.

One-month therapy with trimetazidine sharply decreased the content of free radical oxidation products, lipid peroxides and malonic dialdehyde, in atherogenic low-density lipoproteins in patients with coronary heart disease. Activity of glutathione peroxidase utilizing lipid peroxides in the plasma markedly increased during trimetazidine therapy. The data suggest that trimetazidine not directly interacting with free radicals attenuates the adverse effects of intensive free radical oxidation in coronary heart disease. This effect is mediated via activation of antioxidant enzymes, which diminishes negative consequences of ischemia.

Angina Pectoris↗
PubMed2000

Activity of detoxication enzymes in rat hepatoma 27 transplanted in different organs.

Activities of enzymes of active oxygen forms detoxication and phase II xenobiotic metabolism were measured in rat hepatoma 27 cells transplanted to different organs. Activity of phase II xenobiotic metabolizing enzymes was higher in hepatoma cells growing subcutaneously than in those transplanted into the liver, while activity of active oxygen forms detoxication enzymes (except catalase) was higher in cells transplanted into the liver. Benz(a)pyrene induced the enzyme activities in hepatoma growing both subcutaneously and in the liver.

Aldehyde Dehydrogenase↗
PubMed1997

[The antioxidant probucol as a regulator of the intensity of free-radical lipid peroxidation processes in the blood of patients with coronary atherosclerosis].

Two series of studies were made to assess probucol medicines (lipomal, "Alkaloid"; fenbutol "Akrikhin") effect on clinical symptoms, lipid metabolism, primary and secondary products of lipid peroxidation, activity of antioxidant enzymes (superoxide dismutase, glutathione peroxidase) in atherosclerotic patients with hyperlipidemia type IIA and IIB. In both series probucol reduced frequency of anginal attacks, content of total cholesterol and LDL cholesterol. HDL cholesterol remained unchanged or reduced insignificantly. Lipoperoxides and malonic dialdehyde levels in plasma progressively lowered against activation of antioxidant enzymes. These biochemical parameters returned to initial values within 3 months since the drug discontinuation. It is evident that antiatherogenic effect of probucol is due to indirect activation of natural defense systems responsible for enzymic detoxication of active oxygen forms and lipoperoxides rather than to direct interaction of this synthetic antioxidant with lipid radicals.

Antioxidants↗