Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0039730 (thalassemia)
 10,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The mass concentrations of whole blood reduced glutathione and catalytic activity concentrations of the enzymes, glucose-6-phosphate dehydrogenase (EC 1.1.1.49), glutathione reductase (EC 1.6.4.2) and glutathione peroxidase (EC 1.11.9) were analysed in 25 cases of homozygous beta-thalassaemia, 20 cases of heterozygous beta-thalassaemia and 10 controls. The results showed a significant elevation of reduced glutathione and enzymes of the pentose phosphate pathway in homozygous beta-thalassaemia, indicating the existence of an enzyme-regulated glutathione turnover system in the overt state to combat the augmented red cell membrane damage due to auto-oxidant threat. However, in heterozygous beta-thalassaemia, reduced glutathione was increased, but there was no similar elevation of enzymes except for glutathione peroxidase.
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PMID:Enzymes of the pentose phosphate pathway in glutathione-regulated membrane protection in beta-thalassaemia. 144 62

Red blood cell (RBC) antioxidant defense was investigated in eight individuals with hemoglobin E (Six EE and two E-B(+) thalassemia) and compared to that in six individuals with thalassemia and ten normal subjects. Individuals with hemoglobin E had increased incubated Heinz body formation (68% +/- 18%; p less than 0.001) compared to normal and thalassemic RBC (10% +/- 2% and 11% +/- 5%, respectively). Stimulated pentose phosphate shunt activity was increased in the thalassemic and decreased in the hemoglobin E RBC as compared to normal. The 2,3-diphosphoglycerate (DPG) content of the EE RBC was increased to 5.59 +/- 0.69 mumol/ml RBC as compared to normal (4.51 +/- 0.77; p less than 0.001). In the EE RBC, there was a direct correlation between Heinz body formation and DPG content (r = 0.73). Ascorbic and dehydroascorbic acid (0.1 and 1.0 mM) were able to decrease the degree of Heinz body formation in the hemoglobin E RBC. Ascorbic acid (0.1 mM) prolonged the response of the pentose shunt. Thus impaired antioxidant defense may account for the persistence of the hemoglobin E gene in areas where malaria is endemic. Oxidant medications should be used with caution in individuals of Southeast Asian origin.
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PMID:Impaired antioxidant defense in hemoglobin E-containing erythrocytes: a mechanism protective against malaria? 367 3

13C and 31P magnetic resonance spectroscopy was used to characterize the in vivo kinetics of glucose metabolism and intracellular ATP and 2,3-DPG concentrations in erythrocytes obtained from beta-thalassaemia intermedia, heterozygous beta-thalassaemic and normal individuals and maintained in suspension. Except for an upfield chemical shift in the 2P and 3P resonance of 2,3-DPG in the thalassaemia intermedia erythrocytes, the 31P spectra were comparable between all three blood types, showing similar concentrations of ATP (from 4.5 to 5.2 mumol/g Hb) and 2,3-DPG (from 17.2 to 19.7 mumol/g Hb). However, the profile of glucose metabolism was quite different in beta-thalassaemia intermedia erythrocytes, whereas glucose was consumed at a rate of 0.089 +/- 0.035 fmol/cell/h, significantly higher than that of normal (0.032 +/- 0.018 fmol/cell/h; P = 0.01) and heterozygous (0.025 +/- 0.004 fmol/cell/h; P = 0.01) erythrocytes. This near 3-fold faster rate of glucose metabolism in the thalassaemia intermedia erythrocytes could not be accounted for by any increase in glucose flux via the Embden-Meyerhof pathway, since no significant difference in 3-13C-lactate synthesis was observed among the three blood types (in units of fmol/cell/h, normal, 0.021 +/- 0.013; heterozygous, 0.021 +/- 0.006; beta-thalassaemia intermedia 0.045 +/- 0.025). These results reflect an accelerated rate of glucose metabolism in thalassaemia intermedia erythrocytes because the contribution of reticulocytes to this altered pattern of metabolism could be excluded. As the only other route of glucose metabolism in erythrocytes is the pentose phosphate pathway (PPP), these results indicate that the PPP is more active in beta-thalassaemia intermedia erythrocytes, perhaps as a consequence of their elevated intracellular oxidative state.
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PMID:In vivo metabolic studies of glucose, ATP and 2,3-DPG in beta-thalassaemia intermedia, heterozygous beta-thalassaemic and normal erythrocytes: 13C and 31P MRS studies. 781 67