Effect of sodium citrate on the rate of cholesterol esterification and on the formation of primary products of lipid peroxidation in human blood. Are these processes related?

In vitro experiments show that sodium citrate in a final concentration of 130 mM induces a 4- to 5-fold increase in the activity of lecithin-cholesterol acyltransferase. A parallel determination of the blood content of primary products of lipid peroxidation reveals a 20–30% decrease in diene and triene conjugates and lipid hydroperoxides. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 9, pp. 323–325, September, 1995 Presented by A. N. Klimov, Member of the Russian Academy of Medical Sciences     

Adaptation to periodic hypoxia and a diet supplemented with polyunsaturated class ω-3 fatty acids enhance the resistance of Ca2+ transport in the myocardial sarcoplasmic reticulum to free-radical oxidation

The relationship between the level of accumulation of lipid peroxidation products and the status of the Ca²⁺-transporting system in the sarcoplasmic reticulum of the rat myocardium is studied against the background of two cardioprotective factors, namely adaptation to periodic hypoxia and a diet enriched in polyunsaturated fatty acids of the ω-3 class. It is shown that the diet leads to an increase of level of lipid peroxidation products by 1.8 times in the heart and by 19 times in the liver, whereas a adaptation has no effect on the level of lipid peroxidation products in either of these organs. At the same time, the combined action of both factors considerably enhances the resistance of the myocardial Ca²⁺-transporting system to free radical-induced oxidation. Inin vitro experiments it is shown that adaptation to periodic hypoxia results in a more than twofold deceleration of Ca²⁺ transport inhibition during the oxidation induction by the Fe²⁺/ascorbate system; the diet causes a 3.5-fold deceleration of such inhibition. The results show that the accumulation of a high level of lipid peroxidation products is not always followed by damage to the Ca²⁺-transporting system in the myocardial sarcoplasmic reticulum. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 7, pp. 42–45, July, 1995 Presented by G. N. Kryzhanovskii, Member of the Russian Academy of Medical Sciences     

Antioxidant probucol as an effective scavenger of lipid radicals in low density lipoproteinsin vivo andin vitro

Probucol in concentrations of 10–15 μM effectively inhibits Cu²⁺-induced free radical oxidation of native low density lipoproteins and in concentration of 100 μM it inhibits lipoperoxide formation. The mean plasma concentration of probucol in patients receiving 250 mg of this drug is 25 μM. Both 250 and 1000 mg probucol daily during 3–6 month block the oxidation of isolated low density lipoproteins. Electron paramagnetic resonance spectrometry data showed that probucol incorporatedin vivo into lipoprotein particles interacts with lipid radicals yielding long-lived phenoxyradicals. Probucol can be used in complex therapy of atherosclerosis as an antioxidant drug and its dose required for lipoprotein protection against atherogenic modification can be decreased to 250 mg/day. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 128, No. 8, pp. 186–189, August, 1999     

Lipid peroxidation parameters in the internal organs of rats with different degrees of resistance to hypoxia

Lipid peroxidation and the antioxidant system of the heart, liver, and brain are studied in adult male Wistar rats with high and low resistance to hypoxia tested by “raising” to an altitude of 11.5 km and in intact outbred rats. These parameters are found to be the same in the brain of low- and high-resistance rats, while the brain content of lipid peroxidation products is higher in both groups of Wistar rats compared with outbred rats. The heart and liver parameters are coupled to the resistance to hypoxia. Antioxidant activity prevails over lipid peroxidation in the hearts and livers of high-resistance rats, confirming that oxidation plays a major role in the damaging and lethal effects of acute hypoxia. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, N ^o 1, pp 26–29, January, 1996 Presented by A. I. Archakov, Member of the Russian Academy of Medical Sciences     

Comparison of lipid peroxidation parameters in the heart,liver, and brain of rats with different degrees of resistance to hypoxia

The relationship between the intensity of lipid peroxidation and the activity of the antioxidant system in the heart, liver, and brain is studied in male Wistar rats with low and high resistance to hypoxia tested by being “raised” to an altitude of 11.5 km and in intact outbred rats. It is found that in all groups of rats the content of lipid peroxidation products is highest in the liver, lower in the heart, and lowest in the brain. In all groups, the rate of the ascorbate-induced lipid peroxidation is highest in the brain, lower in the liver, and lowest in the heart. The activity of the antioxidant system is highest in the brain, lower in the liver, and lowest in the heart of low-resistance and outbred rats, while in high-resistance rats it is the same in all the organs. Thus, the difference in the parameters of lipid peroxidation and, particularly, of the antioxidant system in the studied organs is most pronounced in rats with a low resistance to hypoxia. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, N ^o 2, pp. 138–143, February, 1996 Presented by A. I. Archakov, Member of the Russian Academy of Medical Sciences     

The development of free radical processes in experimental bronchospasm. Effect of the bronchodilator preparation troventol

The development of bronchospasm is shown to be accompanied by lipid peroxidation (LPO) activation; 3-fold and 8-fold rises of malondialdehyde concentration are found in homogenate of lung from sensitized animals and from animals provoked with egg albumin antigen, respectively. The use of luminol-dependent chemiluminescence (CL) reveals that in sensitized rats the production of oxygen free radicals is increased by alveolar macrophages activated with phorbol myristate acetate. Troventol at 10⁻³ mg/ml inhibits the CL response of phagocytes both in intact and in sensitized rats and lowers the level of Fe²⁺-induced LPO in lung tissue but not in the liver of intact animals. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 6, pp. 619–621, June, 1994     

Polyunsaturated phosphatidylcholine micelle-induced decrease of atherogenicity of the serumin vitro

It is shown that polyunsaturated phosphatidylcholine administered in micelles stabilized by a plant-derived glycoside prevents the accumulation of cholesterol by cells incubated in atherogenic serum and, moreover, in certain cases causes a 1.4–1.5-fold drop of intracellular cholesterol as compared to control cells. The optimum antiatherogenic effect was achieved when using a micelle concentration of 100–200 μg/ml and an incubation time of at least 4 hours. The antiatherogenic effect was analogous to the effect of high density serum lipoproteins. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 5 pp. 497–501, May, 1995 Presented by Yu. M. Lopukhin, Member of the Russian Academy of Medical Sciences     

Effects of methyluracil and hydroxymethacil on free-radical oxidation in model systems

Three pyrimidine derivatives — methyluracil, hydroxymethacil (a new compound), and its lithium salt — were tested in model systems of differing complexity for antioxidant properties in comparison with the well-known antioxidant ionol. Tests for antiradical activity and for effects on spontaneous and Fe²⁺-ascorbate- or NADPH-dependent lipid peroxidation revealed high antioxidant activity (comparable to that of ionol) of the hydroxymethacil lithium salt. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 8, pp. 142–144, August, 1995 Presented by G.N. Kryzhanovskii, Member of the Russian Academy of Medical Sciences     

Lipid peroxidation level in the focus of compression ischemia in the cerebral cortex of rats

Pathomorphological changes in a focus of ischemia, the level of lipid peroxidation (as indicated by the content of products reacting with thiobarbituric acid), and the postischemic levels of adenyl nucleotides and tissue lipids were studied in rats with focal compression ischemia of the cerebral cortex. An increased level of the TBA-reactive products paralleled by a reduction of the concentrations of adenyl nucleotides and tissue lipids was found to be in clear-cut correlation with the processes of neuronal injury and death and with subsequent repair phenomena in the focus of cortical ischemia. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 12, pp. 589–590, December, 1994 Presented by O. S. Adrianov, Member of the Russian Academy of Medical Sciences     

Effects of diuretics on the intensity of lipid peroxidation and antioxidant protection of blood plasma

An increase in the content of primary and final lipid peroxidation (LPO) products and a decrease in the fat- and water-soluble antioxidants in blood plasma are revealed in a study of hypohydration induced by administration of 40 mg furosemide alone or in combination with 1 tablet of triampure. Intensification of free radical processes in states simulating weightlessness may be related to the loss of fluid due to transformation of water-electrolyte metabolism. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 5, pp. 478–479, May, 1994 Presented by V. N. Smirnov, Member of the Russian Academy of Medical Sciences     

Changes in the serum antioxidant system and lipid peroxidation under the influence of asbestos

The iron content, the state of the serum antioxidant system, and their relationship with the changes in lipid peroxidation in rat liver and lungs at the early stages of chrysotile-asbestos action, and the effect of the naturally occurring flavonoid rutin are studied. Intensification of lipid peroxidation in the liver and lungs and an increase in the oxyproline content, which correlates with the rise in serum antioxidant activity, are observed four weeks after a single intratracheal administration of 50 mg asbestos. The total serum iron content remains unchanged. Rutin has a pronounced anti-asbestos effect, inhibits the early stages of fibrosis, and facilitates normalization of the antioxidant system imbalance induced by asbestos. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 8 pp. 145–147, August, 1994     

Immunochemical analysis of common antigenic determinants in insulin and apoprotein B Molecules

A study is performed of the mechanism underlying stress diabetes, which develops in human beings and animals under stress. Dot-immunoanalysis shows the presence of common antigenic determinants in insulin, apoprotein B, and apoprotein B-containing low density and very low density lipoproteins isolated from human and rat serum. Electrophoresis, immunoelectroblotting, and immunoenzyme analysis reveal 5–6 peptides belonging to apoB, which specifically react with anti-insulin and anti-very low density lipoprotein antibodies. Insulinlike immunoreactivity is also identified in human serum supernatant obtained after precipitation of the total low density and very low density lipoprotein fraction and after removal all lipoproteins from it. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 9, pp. 258–261, September, 1994     

Lipid peroxidation and antioxidant enzymes in the brain of rats exposed to acute emotional stress: Effect of interleukin-1β

Acute emotional stress is shown to raise the level of malonic dialdehyde in the hypothalamus of August rats. After intraventricular administration of interleukin-1β, the malonic dialdehyde level and the activity of antioxidant enzymes tended to rise selectively in the hypothalamus (but not in the sensorimotor cortex) of August, Wistar, and WAG rats. In the presence of this interleukin, acute emotional stress did not cause increases in lipid peroxidation products in the hypothalamus of August rats. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 9, pp. 244–247, September, 1995     

Antenatal effects of ethanol and limontar on lipid peroxidation and the antioxidant defense system in the brain and liver of rat progeny

In contrast to short-term exposure, prolonged exposure to ethanol in the anternatal period is found to inhibit lipid peroxidation in the brain and liver of rats. Activation of the system of antioxidant defense in the brain and liver is observed after both short-and long-term exposure to ethanol. After short-term ethanol exposure, limontar normalizes lipid peroxidation. Translated fromByulleten' Eksperimental'noii Biologii i Meditsiny, Vol. 117, N ^o 1, pp. 41–44, January, 1994 Presented by M. Ya. Studenikin, Member of the Russian Academy of Medical Sciences     

Effect of pH and glutathione on lipid peroxidation in tocopherol-enriched liposomes

Tocopherol-enriched liver microsomes are more resistant to lipid peroxidation at an alkaline pH of 8.5 in comparison with microsomes incubated at pH 7.5. An alkaline pH provides conditions for two-electron oxidation of tocopherol, which causes the lipid molecule to revert to the initial state (O₂/H exchange). A possible mechanism of inhibition of lipid peroxidation within the physiological range of pH with participation of a glutathione-dependent enzyme is discussed. Translated fromByullenten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 9, pp. 268–270, September, 1995 Presented by E. I. Chazov, Member of the Russian Academy of Medical Sciences     

Effects of supplementing the rat diet with selenium on the efficiency of essential linoleic acid metabolism

Examination of the fatty-acid composition of lipids contained in the liver, spleen, blood plasma, aggregated lymphatic follicles of the small intestine, and mesenteric lymph nodes of rats fed diets supplemented with selenium revealed an appreciable effect of this element on the efficiency with which linoleic acid was metabolized to arachidonic acid, which was reflected in an increased 20:4/18:2 ratio. In contrast, Se was found to have little or no effect on levels of lipid peroxidation products in tissues and blood serum. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 8, pp. 136–138, August, 1994     

Carnosine and related compounds inhibit chemiluminescence of human plasma lipoproteinsin vitro

The antioxidant activity of carnosine and related compounds (5 and 10 mM) is assessed from the chemiluminescence curve using a model of Fe-initiated lipid peroxidation of human serum apoB-lipoproteins. These agents lower to different degrees the amplitudes of “fast” and “slow” bursts, the reaction rate, and the chemiluminescence light sum; the latency is prolonged, which may occur upon reduction of lipid hydroperoxides and/or inactivation of free radicals. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 2, pp. 152–154, February, 1995 Presented by I. P. Ashmarin. Member of the Russian Academy of Medical Sciences     

Phosphoinositide response and alterations in free-radical oxidation in rats with catecholamine-induced cardionecrosis

Vascular spasm, hypertrophy of cardiac muscle cells, and necrotic changes in the myocardial tissue of rats administered norepinephrine in incremental doses over 14 days were accompanied by a considerable activation of lipid peroxidation and a weakening of antioxidant defense during the first 7 days of exposure to this injurious agent. On day 14, despite the greatly increased load of norepinephrine, the concentrations of lipid peroxidation products and the activity of antioxidant enzymes deviated from their control values to a lesser extent than on day 7. A similar change was shown by the concentration of brain tissue phosphatidylinositol-4,5-diphosphate, a source of second messengers, suggesting that the phosphoinositide system of second messengers is involved in the mechanisms whereby the destructive effects of norepinephrine are mitigated. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 120, N ^o 8, pp. 137–139, August, 1995 Presented by I. P. Ashmarin, Member of the Russian Academy of Medical Sciences     

Kinetics of lipid unsaturation in blood plasma of mice with Lewis carcinoma

The extreme nature of changes of lipid unsaturation in plasma of mice with Lewis carcinoma is demonstrated. The maximal activation of lipid peroxidation is observed on days 7–9 after transplantation and correlates with the exponential growth of the tumor. From the 9th day the level of double bonds in plasma lipids increases, this coinciding with the first appearance of metastases in the lungs. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 118, N ^o 12, pp. 631–632, December, 1994 Presented by S. M. Navashin, Member of the Russian Academy of Medical Sciences     

Correction of hyperlipoproteinogenic microangiopathy and organ pathology with thymalin and leu-enkephalin in the early stages of atherogenesis

The effects of thymalin and leu-enkephalin on lipid peroxidation and microcirculatory disorders in the early stages of atherogenesis are compared. Correction of the generalized microcirculatory response to hyperlipoproteinemia with the peptides manifested itself in the regression of atherosclerotic lesions in the aorta and restoration of the morphofunctional state of the myocardium and liver. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, N ^o 1, pp. 108–111, January, 1996