Skin lipids in rats administered with melatonin

Effects of the pineal hormone melatonin on skin lipids in Wistar rats were studied by thinlayer chromatography. The reaction was shown to be delayed. Contents of total lipids and the majority of fractions increased over 24 h after administration of melatonin. Concentrations of triglycerides and phospholipids decreased, while the contents of cholesterol, cholesterol esters, and free fatty acids increased by the end of the second day. Our findings indicate that the blood and subcutaneous fat, as well as changed metabolic interrelations of skin lipids are involved in the skin response to increased melatonin concentration. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 127, No. 4, pp. 463–465, April, 1999     

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     

Two mechanisms of progesterone action on the skin (Results of biochemical analysis)

Effects of progesterone on functional activity of lysosomes and lipid peroxidation are measured in the skin of rats in relation to its dose, duration of exposure to it, and skin tissue type (epidermis and dermis). This hormone is shown to regulate both lipid peroxidation intensity and lysosomal activity. It is concluded that these two affects represent two mechanisms through which progesterone exerts its anti-inflammatory effect on the skin. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 8, pp. 173–176, August, 1996     

Multiresistance and lipid peroxidation system of thermoresistantShigella sonnei strains

The content of lipid peroxidation products increases in lipids isolated fromShigella sonnei after heating. Thermoresistant strains are characterized by higher activity of superoxide dismutase and catalase and by stable activity of glutathione reductase and glutathione transferase compared with thermolabile strains. Thermoresistant strains are also resistant to some antibiotics and hydrogen peroxide. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 7, pp. 69–71, July, 1996     

Effect of He-Ne laser radiation on lipids in platelets

Low-intensity He-Ne laser radiation induces metabolic rearrangements in platelet lipids and activates some lipid-dependent systems of cell regulation as well as the synthesis of lipid-like second messengers. Modification of the lipid phase and physicochemical state of biological membranes are the molecular basis of biochemical adaptation of the platelets to laser radiation. Translated fromByulleten' Eksperimental'noi Biologii i Medisiny, Vol. 127, No. 1, pp. 43–45, January, 1999     

Effects of sex steroid hormones on lipid peroxidation and glutathione antioxidant system in rat skin

Effects of estradiol and testosterone on the intensity of lipid peroxidation and contents of glutathione redox system components in the dermis and epidermis of rat skin were studied. Only estradiol induced considerable dose-dependent and tissue-specific biphasic antioxidant effects on the skin. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 128, No. 12, pp. 663–666, December, 1999     

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     

Effect of diazepam on the transmembrane potential and physicochemical state of the thymocyte membrane in rats during exposure to cold

Exposure of restrained rats to cold caused a drop in rectal temperature by 3°C, attenuated membrane potential by ΔΨ_T, decreased the level of lipid peroxidation products, and increased the viscosity of membrane lipids in thymocytes. Although diazepam (5 mg/kg, 1 h prior to experiment) decreased ΔΨ_T and lipid viscosity under comfortable temperature, it prevented the cold-induced changes in these parameters. Incubation of intact rat thymocytes with diazepam (0.2 μg/ml) decreased ΔΨ_T, increased lipid viscosity, and did not change the intensity of lipid peroxidation. Possibilities are discussed to reduced with the help of diazepam the cold-related energy losses not only due to its effect on the central benzodiazepine receptors, but also due to changes in functional and structural parameters of the membranes caused by interaction with peripheral receptors. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 12, pp. 636–639, December, 1998     

Structural changes in the erythrocyte plasma membrane in dehydration

Changes in the lipid bilayer and glycocalyx of the erythrocyte plasma membrane are studied by the method of spin labels in dehydrated rats. No appreciable chantes are found in the membrane of erythrocytes from rats deprived of water for 3 days. Changes occur in the glycocalyx after a 6-day dehydration, while a 12-day dehydration induces irreversible changes in the plasma membrane lipids and the erythrocyte surface areas. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 122, No. 10, pp. 402–404, October, 1996     

Effect of ethanol concentration on the maximal specific growth rate and biomass composition ofYarrowia lipolytica mutant strain No. 1

the effect of ethanol concentration on the maximal specific growth rate and biomass composition ofYarrowia lipolytica No. 1 was studied during culturing in the pH-auxostat mode. Growth inhibition set in starting from a 2.64 g/liter residual concentration of ethanol. The constant of ethanol inhibition was 11.0 g/liter. Growth inhibition with ethanol was associated with changes of the fatty-acid composition of lipids and a resultant reduction of lipid unsaturation. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, N ^o 1, pp. 71–73, January, 1996 Presented by Yu. A. Romanov, Member of the Russian Academy of Medical Sciences     

Opposite effects of adaptation to short-term stress and adaptation to periodic hypoxia on Na,K-ATPase activity in liver plasma membranes

Na,K-ATPase activity is shown to be lowered more than twice 2 hours after emotional pain stress in comparison with the initial level, remaining practically unchanged during the subsequent 24 hours. Adaptation to repeated stress results in a 50% activation of Na,K-ATPase. A protective effect is demonstrated in long-term stress against the background of preadaptation. Adaptation to periodic hypoxia inhibits liver Na,K-ATPase to the same extent as does acute stress. Against the background of preadaptation to periodic hypoxia, stress does not aggravate the drop of Na,K-ATPase activity. Adaptation to stress inhibits accumulation of products ofin vitro-induced lipid peroxidation in the heart 1.4-fold and does not affect it in the liver, whereas adaptation to hypoxia sharply accelerates the accumulation of oxidized products in both organs, which probably explains the activation of liver Na,K-ATPase in adaptation to stress and its inhibition in adaptation to hypoxia. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, No. 4, pp. 383–386, April, 1996 Presented by G. N. Kryzhanovskii, Member of the Russian Academy of Medical Sciences     

Experimental effect of some hormones on the intensity of the free-radical lipid oxidation reaction

The effect of adrenalin and hydrocortisone on free-radical oxidation of lipids in erythrocytes was investigated in experiments on rabbitsin vivo with modified lipid metabolism. Adrenalin in a dose of 0.1 mg/kg and hydrocortisone in a dose of 5 mg/kg were found to cause an, increase in the concentration of hydroperoxides of fatty acids. The results confirm the view that adrenalin and hydrocortisone, in experimentsin vivo, have antioxidative properties which are evidently indirect in character, associated with their lipid-mobilizing effect.Institute of Clinical and Experimental Medicine, Siberian Branch, Academy of Medical Sciences of the USSR, Novosibirsk. (Presented by Academician of the Academy of Medical Sciences of the USSR V. P. Kaznacheev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 86, No. 11, pp. 531–533, November, 1978.     

Effect of picrotoxin-induced seizures on lipid composition of cortical tissue homogenate and its nuclear fraction in rats

The content of lipids in rat cortical tissue homogenate and fraction of neuronal nuclei was determined under normal conditions and after picrotoxin-induced seizures. Changes in lipid composition of homogenate and nuclear fraction differed considerably. In homogenate, the content of sphingomyelin, lysophosphatidylcholine, and total phospholipids increased, while the content of free fatty acid remained unchanged; in the nuclear fraction the total phospholipid content decreased, while the concentration of free fatty acids increased. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 130, No. 9, pp. 292–294, September 2000     

Effect of repeated cold stress on intensity of lipid peroxidation and tissue antioxidant system

Repeated cold stress performed in a cold-tempering mode reduces lipid peroxidation and activates tissue antioxidant system. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 125, No. 4, pp. 385–387, April, 1998     

Effect of a long low-power γ-irradiation and β-carotene on lipid metabolism in the rat thymocyte nuclei

The effect of γ-irradiation in a dose of 1.5 Gy at a dose intensity of 3 sGy/day on the rat thymocyte nuclear lipids and of β-carotene diet on the metabolism of thymocyte nuclear lipids is studied in intact and γ-irradiated rats. The irradiation activated the incorporation of 2-¹⁴C-acetate in the total lipid fraction and in cholesterol and suppressed the label incorporation in sphyngomyelin. The β-carotene diet decreased the content of cholesterol and monoglycerides in the thymocyte nuclei of intact and irradiated rats. In irradiated rats β-carotene increased the label incorporation in the total phosphatidylserine+phosphatidylinositol fraction. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 9, pp. 311–313, September, 1998     

Effect of picrotoxin-induced seizures on lipid composition of cortical tissue homogenate and its nuclear fraction in rats

The content of lipids in rat cortical tissue homogenate and fraction of neuronal nuclei was determined under normal conditions and after picrotoxin-induced seizures. Changes in lipid composition of homogenate and nuclear fraction differed considerably. In homogenate, the content of sphingomyelin, lysophosphatidylcholine, and total phospholipids increased, while the content of free fatty acid remained unchanged; in the nuclear fraction the total phospholipid content decreased, while the concentration of free fatty acids increased. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 130, No. 9, pp. 292–294, September 2000     

Antioxidant effect of cytochromec under conditions of prolonged immobilization stress

Prolonged immobilization stress activates lipid peroxidation, causes ischemic damage to the myocardium, and promotes the development of some manifestations of atherosclerosis in rabbits. Intravenous infusion of cytochromec (1 mg/kg) during 30 days of immobilization lowers the extent of lipid peroxidation and produces cardio- and endothelium-protective effects. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 123, No. 6, pp. 642–644, June, 1997     

Steroid hormones modulate lipid spectrum in lysosomal membranes of skin fibroblasts

It is shown that estradiol and hydrocortisone modulate lipid composition and affect lipidprotein interaction in fibroblast lysosome membranes, which can promote enzyme release from lysosomes. These effects are particular mechanisms of hormone regulation of functional lysosome activity in the skin. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 125, No. 2, pp. 165–167, February, 1998     

Adaptation to altitude hypoxia limits lipid peroxidation during inflammation and stress

Preadaptation of rats to altitude hypoxia results in reduced activation of lipid peroxidation during subsequent stress, inflammation, or both, as compared to hypoxiaunadapted animals, with the result that secondary changes in organs and tissues of adapted rats are much less pronounced and conditions are created for alleviating the acute inflammation and the stress reaction. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, N ^o 6, pp. 590–593, June, 1995 Presented by E. D. Gol'dberg, Member of the Russian Academy of Medical Sciences     

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 licoriceGlycyrrhiza 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 β-carotene-containing preparations carinat and carinat CD. Parapharmaceutics containing both licoriceGlycyrrhiza glabra root powder and β-carotene (carinat forte) markedly increased antioxidant activity of the liver. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 130, No. 7, pp. 56–58, July, 2000