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Biomedical subjects

O B Liubitskiĭ

Publications and source records attributed to O B Liubitskiĭ.

9 recordsLinked to original sources
PubMed2003

[Involvement of tetrahydrobiopterin in local change of endothelium-dependent vasorelaxation in pulmonary hypertension].

A deficiency of tetrahydrobiopterin (BH4), a NO-synthase co-factor, results in reactive oxygen species synthesis by NO-synthase. It leads to disturbances of endothelium-dependent vasorelaxation. We performed our study on the monocrotaline model of pulmonary hypertension. A decrease in endothelium-dependent relaxation was observed only in intrapulmonary arteries of monocrotaline-treated rats. A perfusion of BH4 (0.1 mol/liter) increased significantly endothelium-dependent dilation of hypertensive pulmonary arteries (p < 0.01). But BH4 did not influence the relaxation of systemic vessels and the dilation responses of pulmonary and systemic arteries of control rats. Measuring of superoxide by lucigenin-mediated chemiluminescence showed five-fold O2- production in intrapulmonary arteries of pulmonary hypertensive rats, that was activated by acetylcholine and inhibited by a nonselective NO-synthase blocker (L-NAME). However, activity of NO-synthase measured as [H3]arginine to [H3]citrulline conversion and assessed in pulmonary vessels and aortic tissue, did not differ in control and monocrotaline-treated groups. These data suggest, that there is a local deficiency of BH4--in pulmonary vessels, without significant changes of systemic circulation.

Animals↗
PubMed1999

[Serum antioxidative activity].

Model systems used in the determination of serum antioxidative activity (AOA), which differ both in the way of generating free radicals and in the mode of their detection, are clinically analyzed. The specific features and potentialities of the model systems developed at the authors' laboratory are characterized. These included yolk lipoprotein suspensions, liposomal suspensions formed from total phospholipid fraction, the hemoglobin-hydrogen peroxide-luminol system. The investigations show that most model systems for determining serum AOA contribute to the water soluble interceptors of free radicals (ascorbate, urate, plasma proteins, etc.), chelating and oxidative agents of catalytically active Fe2+ (ceruloplasmin, transferrin, albumin, etc.). The serum AOA levels measured with different model systems vary with the body's status. To determine serum AOA and the contribution of major endogenous antioxidants and inhibitors of free radical reactions may be a basis for the goal-oriented use of exogenous antioxidants in the therapy of a great variety of diseases.

Animals↗
PubMedDate not supplied

[Antioxidant properties of arbidol and its structural analogs].

The effect of arbidol and its structural analogues on the process of lipid peroxidation in phospholipid liposomes induced by Fe2+ has been investigated. It was shown that the antioxidant efficacy of arbidol and its derivatives is lower than that of alpha-tocopherol by two or three times. It was suggested that the mechanism antioxidant action of the arbidol and its structural analogues consists of scavenging of lipid radicals rather than chelating of Fe2+.

Antioxidants↗
PubMedDate not supplied

[Dynamics of lipid peroxidation and blood antioxidant system during acute destructive pancreatitis].

The changes of lipid peroxidation parameters and state of blood serum antioxidant system in acute destructive pancreatitis were investigated. The increased content of blood serum diene conjugates and thiobarbituric acid reactive substances was found. It was shown that the blood serum antioxidant activity had correlated with concentration of urate (r = +0.79, p < 0.001).

Adult↗
PubMedDate not supplied

[Antioxidant properties of 3-oxypyridine analogues: mexidol, emoxipin, proxipin].

Using three chemiluminescent model systems of oxidation (suspension of phospholipid liposomes, a geous solution of haemoglobin-hydrogen peroxide-luminol and a geous solution 2,2'-azo-bis-(2-methylpropionamidine)dihydrochloride-luminol) the antioxidant activity and mechanism of antioxidant action of three 3-oxypyridine analogues: (mexidol, emoxipin and proxipin) were studied. These compounds were shown: a) to interact with catalitically active two valency iron ions (Fe2+), that causes elimination of ions from the model system; b) to scavenge reactive oxygen species and/or luminol radicals produced in the model systems. Their activity reduced in the following order: mexidol > emoxipin > proxipin. The antioxidant activity of 3-oxypyridines may underline known clinical effects of these compounds.

Antioxidants↗
PubMedDate not supplied

[The use of flavonoid antioxidants in the complex treatment of patients with peripheral vitreo-chorioretinal dystrophies and dystrophic retinal detachment].

Parameters of lipid peroxidation (LP) and antioxidant activity (AOA) of tear and blood plasma were examined in 22 healthy subjects (44 eyes) as well as in 33 patients with peripheral vitreochoreoretinal dystrophies (PVCRD--60 eyes), in 32 patients with non-operated dystrophic retinal detachment (DRD--34 eyes) and in 135 patients with operated retinal detachment, stable visual functions and with the postoperative period ranging from 4 months to 10 years (137 eyes). The results denoted a lower tear AOA (on the average by 35%) in patients with DRD and PVCRD, whereas, the blood plasma AOA or LP products' content remained unchanged. It is indicative of a local nature of metabolic impairments, specifically, of impairments in the system of antioxidant protection of the eye. Flavonoid antioxidants (dikvertin and ginkgo biloba) reduced the content of LP products, and induced the AOA in tear and blood plasma in patients with PVCRD and retinal detachment; they also improved the visual functions in patients with operated retinal detachment. Therefore, the flavonoid antioxidants can be recommended for adding to the complex treatment of PVCRD and DRD for the purpose of improving and stabilizing the visual functions and for neuroprotection.

Administration, Oral↗
PubMedDate not supplied

[Antioxidant activity of inhibitors of free radical reactions in the dressing materials for wound healing].

Antioxidant activity (AA) of inhibitors of free radical reactions (FRR) (dieton, mexidol, trypsin), aplied to the dressing material for wound healing was studied. In our work we used a model system containing suspension of laminated liposome, formed from fraction of total chicken yolk phospholipids. Lipid peroxidation (LPO) of liposome membranes was initiated by addition of Fe2+ ions. The kinetics of FRR was followed by coumarine-enhanced chemiluminescence (CL). It was found that AA of the inhibitors was determined by their ability to intersept aqueous and hydrofobic free radicals and chelate Fe2+ ions. Their ability to intersept radicals reduced in the following order: dieton > trypsin > mexidol. In addition we discovered unknown ability of mexidol to interact with Fe2+, that resulted in elemination of FRR catalyst. Investigating AA of the FRR inhibitors in the two-components mixture, consisting of dieton and mexidol, we observed the effect of multifunctionality: dieton, increased the duration of latent period of CL by intersepting lipid peroxyl radicals, while mexidol, decreased its value by interacting with Fe2+, i.e. mexidol masked the action of dieton. Investigating AA of two-components mixture, consisting of mexidol and trypsine, we observed the same effect of multifunctionality. In the two-component mixture, consisting of trypsine and dieton, the action of the inhibitors was found to be synergistic. All antioxidant properties of these FRR inhibitors were also preserved in the three component mixture. Hence, mixture components, dieton, mexidol and trypsin, possess high AA, that validates their use in dressing materials employed for wound healing.

Antioxidants↗
PubMedDate not supplied

[The measuring of blood plasma antioxidant activity by the hemoglobin-hydrogen peroxide-luminol system].

The method of valuation of the blood plasma antioxidant activity (AOA) by the hemoglobin-hydrogen peroxide-luminol chemiluminescence system has been proposed. The method is based on the measuring the induction time of chemiluminescence that is directly proportional to the added volume of plasma or concentration of standard antioxidant. The ascorbate was taken as a standard. Blood plasma AOA has been expressed through the concentration of equivalent ascorbate solution (ascorbate equivalent). The influence of hemolysis and storage conditions of plasma on its detected AOA was investigated. The change of human blood plasma AOA after single administration of 2 g the ascorbate and its dynamics in patients with acute pancreatitis was studied.

Acute Disease↗