1,721,079 research outputs found
Variations in the fatty acid composition of rat erythrocyte membrane lipids at different ages [Variazione della composizione in acidi grassi dei lipidi della membrana dell'eritrocita nel ratto a differente eta']
No full textThe fatty acid composition of the erythrocyte lipids was studied in newborn, growing and adult rats. The percentage of oleic acid progressively decreased from the birth up to the adult age, while that of linoleic acid markedly increased. A smaller increase was also seen in the arachidonic acid content. These changes do not seem to be accounted for by differences in the percentages of the major phospholipid fractions or to differences in the age of the erythrocyte. Rather, variations in the fatty acid pattern of the various fractions of plasma lipids seem to be responsible for the lipid changes in the erythrocyte membrane
Allyl alcohol-induced hemolysis and its relation to iron release and lipid peroxidation
No full textAllyl alcohol administration to starved mice produced, along with liver necrosis, a high incidence (about 50%) of hemolysis. A marked decrease in erythrocyte glutathione (GSH) was seen in all the intoxicated animals. Such a decrease was significantly higher in the animals showing hemolysis. In these animals a substantial amount of malonic dialdehyde (MDA) was detected in plasma and a marked decrease in arachidonic and docosahexaenoic acids was found in erythrocyte phospholipids. These data suggest that the allyl alcohol-induced hemolysis is mediated by lipid peroxidation. In vitro studies have shown that the addition of acrolein to mouse erythrocytes produces a dramatic GSH depletion, which is followed by the appearance of lipid peroxidation and, after an additional 30 min of incubation, by the development of hemolysis. Prevention of lipid peroxidation by an antioxidant (Trolox C) or an iron chelator (desferrioxamine, DFO), prevented hemolysis even if the erythrocyte GSH level was dramatically decreased. In vitro, allyl alcohol and acrylic acid were ineffective in inducing GSH depletion, lipid peroxidation and hemolysis. Studies of possible induction of lipid peroxidation in erythrocytes showed that a progressive increase in "free" (desferal chelatable) iron occurs in the erythrocytes during the incubation with acrolein. It seems, therefore, that a release of iron from iron-containing complexes occurs in acrolein-treated erythrocytes and that such "free" iron promotes lipid peroxidation. © 1989
Variations of fatty acid composition of erythrocyte and plasma lipids in the rat during the first period of life
No full textThe changes occurring in the fatty acid composition of the erythrocyte lipids during the first weeks of life were studied in the rat. The major changes consisted of a progressive decrease in oleic acid and a progressive increase in linoleic acid. A lower but significant increase in arachidonic acid was also observed. These changes are not related to variations in erythrocyte age; rather, they appear to be related to the age of the animal. Since somewhat similar changes were observed in the fatty acid composition of the major lipid classes of plasma during the first weeks of life, the possibility that these variations could account for the changes in the fatty acid composition of erythrocyte lipids was considered. Some support to this possibility was found in the results of experiments in which erythrocytes taken from 15-day-old rats were incubated with plasma taken from newborn rats. The changes in the fatty acid composition of erythrocytes and plasma lipids do not appear to be dependent on dietary lipids, since they occur during the suckling period, i.e., before the rats begin to ingest the pelleted diet which presents a fatty acid pattern completely different to that of the dams' milk. © 1983 American Oil Chemists' Society
Variations in erythrocyte enzymatic activity in the first days of life [Variazioni di attività enzimatiche eritrocitarie nei primi giorni di vita]
No full textThe erythrocyte activities of glucose 6-phosphate dehydrogenase, pyruvate kinase and glucose phosphate isomerase decrease during the first days of life. Furthermore the level of these enzymatic activities is higher in newborn infants with higher percentage of carboxyhemoglobin. It is likely that a premature and rapid fall of reticulocytes causes a decrease in enzymatic activities sensitive to aging and that the higher hemolysis can represent a disappearance of oldest erythrocytes which present lower enzymatic activities. These data therefore confirm the block in erythropoiesis in the first hours of life
Fatty acid pattern of the erythrocyte lipids and plasma vitamin e in the first days of life
No full textThe plasma level of vitamin E is lower in newborns than in adults. The fatty acid composition of the erythrocyte lipids changes during the first weeks of life, the major changes being the increase of linoleic acid and the decrease of arachidonic acid. These changes cannot be ascribed to variation of erythrocyte age, but they seem to be related to variations in the fatty acid pattern of the major lipid fractions of plasma. The lowest ratio between vitamin E in plasma and the percentage of polyunsaturated fatty acids in erythrocyte membrane is reached in the first few days following the beginning of feeding. The results are discussed in relation to the development of hemolysis during the first days of life. © 1981 S. Karger AG, Basel
Iron release, lipid peroxidation, and morphological alterations of erythrocytes exposed to acrolein and phenylhydrazine
No full textIron is released in a free [desferrioxamine (DFO)-chelatable] form in mouse erythrocytes incubated with the oxidizing agents acrolein and phenylhydrazine or in erythrocytes drawn from allyl alcohol-intoxicated mice. The release is accompanied by peroxidation of membrane lipids when the cells are depleted of glutathione. Lipid peroxidation is always followed by the lysis of the cells. The release of iron is also accompanied by methemoglobin formation, but the extent of the release does not correlate with the level of methemoglobin production. The addition of DFO to the incubation mixture or the preincubation of the erythrocytes with DFO in millimolar concentrations completely prevents both lipid peroxidation and hemolysis while not significantly changing the level of iron release. Morphological studies carried out with scanning electron microscopy showed a number of alterations in the shape of the incubated erythrocytes, including echinocyte transformation and the appearance of codocyte, stomatocyte, and cnizocyte like forms. These alterations were more prominent with increasing lipid peroxidation and hemolysis, even if occurring in their absence. On the contrary, the appearance of pits and holes was strictly associated with lipid peroxidation and lysis. © 1994 Academic Press, Inc
Plasma F2-isoprostanes are elevated in newborns and inversely correlated to the gestational age
No full textProtection of erythrocytes against oxidative damage and autologous immunoglobulin G (IgG) binding by iron chelator fluor-benzoil-pyridoxal hydrazone
No full textIron is released in a free desferrioxamine-chelatable form when erythrocytes are challenged by an oxidative stress. The release of iron is believed to play an important role in inducing destructive damage (lipid peroxidation and hemolysis) or in producing membrane protein oxidation and generation of senescent cell antigens (SCA). In this report, we further tested the hypothesis that intracellular chelation of iron released under conditions of oxidative stress prevents erythrocyte damage or SCA formation. Fluor-benzoil-pyridoxal hydrazone (FBPH), an iron-chelating molecule of the family of aromatic hydrazones, was prepared by synthesis and used for the above purpose after the capacity of the product to enter cells had been ascertained. GSH-depleted mouse erythrocytes were incubated with the oxidant drug phenylhydrazine in order to produce iron release, lipid peroxidation, and hemolysis. FBPH at a concentration of 200 μM prevented lipid peroxidation and hemolysis in spite of equal values of iron release. FBPH was active even at a lower concentration (100 μM) when the erythrocytes were preincubated with it for 15 min. No preventive effect was seen when FBPH saturated with iron was used. Prolonged aerobic incubation (60 hr) of erythrocytes produced iron release and formation of SCA as determined by autologous immunoglobulin G (IgG) binding. The IgG binding was detected by using an anti-IgG antibody labeled with fluorescein and by examining the cells for fluorescence by confocal microscopy. FBPH prevented SCA formation in a dose-related manner. These results lend further support to the hypothesis that iron release is a key factor in erythrocyte ageing. (C) 2000 Elsevier Science Inc
- …
