Enzymes of the pentose phosphate pathway in glutathione-regulated membrane protection in beta-thalassaemia

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.