Das Verhalten von Triphospho-pyridinnucleotid, Flavinadenin-dinucleotid, Coenzym A und Thiaminpyrophosphat in Hämolysaten von Kaninchen-Reticulocyten und -Erythrocyten

Hofmann, E; Rapoport, S.; Kesselring, Kurt

doi:10.1515/bchm2.1956.304.1-2.157

Cited by 20 publications

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“…This is in agreement with the work of Hofmann and Rapoport (46) who found that rabbit reticulocytes had two to three times the ATP content of the average circulating erythrocyte. The human red cell contains a considerable store of 2: 3 DPG with a high energy content (AF, 16,000 calories).…”

supporting

confidence: 93%

Alterations in Metabolic Energetics and Cation Transport During Aging of Red Cells

Bernstein¹

1959

J. Clin. Invest.

189

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With the total life span of the human red cell averaging 120 days, about 0.8 per cent of the circulating erythrocytes disintegrate daily. Normal red cell destruction has been attributed to extra-and intracorpuscular factors (1, 2); until recently, little attention has been paid to the intrinsic processes of impaired function in normal red cells that may lead to possible disintegration. The metabolic energy of the red cell is predominantly derived from glycolytic mechanisms and is utilized to maintain transport and membrane functions and to prevent the auto-oxidation of hemoglobin (3). This investigation was designed to ascertain whether alterations in glycolysis and the activity of certain crucial enzymes concerned in the Embden-Meyerhof path occur with the in vivo aging of circulating red cells.Centrifugation of blood aggregates young red cells (including reticulocytes) in the top layers of the packed red cell column (4, 5). Examination of layers of centrifuged red cells after Fe59 administration reveals that, five to 15 days later, high radioactivity is incorporated in the top fraction, while at subsequent stages in the life span, the greatest radioactivity is present in the bottom layer (6, 7). Fractionation of red cell samples on the basis of increasing density of the erythrocyte population with age has revealed decreases in content of water, solids and cations (4,8), lipids (7) and enzyme activity (5) MATERIALS AND METHODSHeparinized blood from humans (normal and in response to hemorrhage) was collected in plastic or siliconed glass for centrifugation in blood cell separation tubes at 500 G for 15 minutes; the plasma was removed for respinning to obtain a cell-free preparation and the buffy coat completely removed from the constricted part of the tube. The red cells from the bottom bulb of the tube were suspended in isotonic saline (either buffered or containing dextran or 20 per cent bovine albumin) to make a 40 per cent suspension, and a portion, constituting the original red cells, retained for analysis. After standing for 10 minutes, the remainder of the suspension was spun at 100 G for 10 minutes, followed by 2,000 G for 45 minutes. Where necessary, the estimations detailed have been corrected for the intercellular fluid trapped between the packed cells at different levels in the centrifuged cell column by the Evans blue method (13) in a separate sample spun under identical conditions.

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confidence: 93%

Alterations in Metabolic Energetics and Cation Transport During Aging of Red Cells

Bernstein¹

1959

J. Clin. Invest.

189

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“…DISCUSSION A striking reduction in the ability to incorporate nicotinic acid and nicotinamide into the pyridine nucleotides is evident in mature erythrocytes when these cells are compared with reticulocytes obtained from rabbits with an acetylphenylhydrazine-induced hemolytic anemia. Since the concentrations of DPN and of TPN are essentially the same in reticulocytes as in erythrocytes (27), the findings described here indicate a more rapid turnover of these cofactors in reticulocytes.…”

Section: Resultssupporting

confidence: 51%

The Incorporation of Nicotinic Acid and of Nicotinamide Into the Pyridine Nucleotides of Erythrocytes and Reticulocytes of Rabbits in Vitro*

Jaffé¹,

Gordon²

1963

J. Clin. Invest.

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There is abundant evidence that loss of intracellular structure and alteration in metabolic activity occur as mammalian reticulocytes mature to become nonreticulated erythrocytes (2). Loss of the ability to synthesize heme (3), proteins (3, 4), lipids (5-7), purine nucleotides (8), and pyrimidine nucleotides (9) from small molecule precursors accompanies the disappearance of mitochondria, ribosomes, and ribonucleic acid from reticulocytes. An intact Krebs tricarboxylic acid cycle and a complete cytochrome system are not present in the mature mammalian erythrocyte (10). The concentration of ATP is approximately 2.5 times greater in rabbit reticulocytes than in the mature erythrocytes of rabbits (11). Further changes, including a progressive decrease in the activity of several enzymes of the glycolytic pathway (12) and of the hexose monophosphate shunt pathway (12, 13) and in the concentration of ATP (12,14), are associated with aging of mature mammalian erythrocytes in vivo. The concentrations of DPN and of TPN of avian and human erythrocytes were reported to decrease during storage in vitro (15), and the concentration of DPN in human erythrocytes was found to decrease with aging in vivo (16). It was of interest, therefore, to study in more detail the metabolism of the pyridine nucleotides in mammalian erythrocytes as a function of the age of the cells. The present report provides evidence for a difference in the ability of reticulocytes and of mature erythrocytes of rabbits to incorporate radioactive nicotinic acid and nicotinamide into DPN and TPN in vitro. MATERIALS AND METHODSWhole blood, anticoagulated with heparin, was obtained from normal, adult, white New Zealand rabbits. In order to obtain blood enriched with reticulocytes, rabbits were made severely anemic by the administration of acetylphenylhydrazine, 10 mg per kg daily for 5 days. These rabbits were exsanguinated 2 days after the final injection. The blood was centrifuged immediately, the plasma and buffy coat were removed, and the cells were washed three times with 4 to 5 vol of cold 0.9% sodium chloride solution. Flasks for incubation were prepared to contain 10 ml of erythrocytes or reticulocytes, 1.6 to 1.7 ,emoles and 9.4 to 10.0 ,uc of radioactive nicotinic acid or nicotinamide, 870 ,umoles of glucose, 140 ,umoles of glutamine, 330 jcmoles of inorganic phosphate, 9 mg of penicillin, and 9 mg of streptomycin in a total volume of 15 ml. The specific activity of the nicotinic acid-7-C14 was 5.9 ,c per ,umole and that of the nicotinamide-7-C'4 was 5.6 lc per uemole.1 In experiments in which different concentrations of nicotinic acid were employed, the specific activity was reduced proportionally by the addition -of unlabeled compound.

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“…The ATP concentration decreased in older cells. Hofman and Rapoport (1956) also found that rabbit reticulocytes had two to three times the ATP content of the average circulating erythrocyte. It is possible that most or all the cells in the lightest fraction were reticulocytes and had an increased ATP concentration.…”

Section: Discussionmentioning

confidence: 85%

Cytodifferentiation and Membrane Transport Properties in LK Sheep Red Cells

Lee

Woo

Tosteson

1966

The Journal of General Physiology

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Young cells produced in LK sheep during rapid hematopoiesis after massive hemorrhage contain more K than the cells which are normally released into the circulation. The K content in these new cells falls to that characteristic of mature LK cells after a few days in the circulation. K transport properties in young and old cells before and after massive bleeding were studied. Young and old cells were separated by means of a density gradient centrifugation technique. Evidence showing that younger cells are found in the lower density fractions is presented. Active transport of K in the lightest fraction as measured by strophanthidin-sensitive influx was four to five times greater in red cells drawn 6 days after massive bleeding while the K leak as measured by strophanthidin-insensitive influx was only slightly larger. No change after bleeding was observed in older cells which had been present in the circulation prior to the hemorrhage. It is concluded that the high K content of young cells produced in LK sheep after bleeding is due to temporary retention of membrane K transport properties characteristic of HK cells. Thus, genetically determined modification of membrane transport properties has been shown to occur in nondividing circulating red cells.

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Das Verhalten von Triphospho-pyridinnucleotid, Flavinadenin-dinucleotid, Coenzym A und Thiaminpyrophosphat in Hämolysaten von Kaninchen-Reticulocyten und -Erythrocyten

Cited by 20 publications

References 0 publications

Alterations in Metabolic Energetics and Cation Transport During Aging of Red Cells

Alterations in Metabolic Energetics and Cation Transport During Aging of Red Cells

The Incorporation of Nicotinic Acid and of Nicotinamide Into the Pyridine Nucleotides of Erythrocytes and Reticulocytes of Rabbits in Vitro*

Cytodifferentiation and Membrane Transport Properties in LK Sheep Red Cells

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