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Biomedical subjects

E Beutler

Publications and source records attributed to E Beutler.

At least 469 records · Page 26Linked to original sources
PubMed1974

Useful agents for the study of glutathione metabolism in erythroyctes. Organic hydroperoxides.

t-Butyl hydroperoxide and cumene hydroperoxide, both known to be substrates for glutathione peroxidase, were used to oxidize erythrocyte GSH. Addition of concentrations of hydroperoxides equimolar with respect to GSH in the erythrocytes or whole blood quantitatively oxidizes GSH in the erythrocytes with a half-time of 4.5s at 37 degrees C and about three times as long at 4 degrees C. In the presence of glucose, normal erythrocytes regenerate all the GSH in about 25min. However, glucose 6-phosphate dehydrogenase-deficient erythrocytes failed to regenerate GSH. Treatment of erythrocytes with hydroperoxides does not affect erythrocyte survival in rabbits. Oxidation of erythrocyte GSH with equimolar concentrations of hydroperoxides does not lead to formation of mixed disulphides of haemoglobin and GSH. The hydroperoxides do not affect erythrocyte glycolytic and hexose monophosphate-shunt-pathway enzymes. Previous studies on transport of GSSG from erythrocytes were confirmed by using t-butyl hydroperoxide to oxidize erythrocyte GSH.

Animals↗
PubMed1974

The reduction of glyceraldehyde by human erythrocytes. L-hexonate dehydrogenase activity.

Incubation of red cell suspensions with D-glyceraldehyde resulted in disappearance of glyceraldehyde and appearance of glycerol. Concomitantly, there was an increase of CO(2) formation from glucose. This indicated that the reduction of glyceraldehyde to glycerol occurred through a NADPH-linked system. Studies in hemolysates revealed the presence of an enzyme with the capacity to catalyze the reduction of glyceraldehyde to glycerol by NADPH. This enzyme was partially purified by DEAE chromatography. The elution pattern of the enzyme and its kinetic characteristics indicated that the enzyme was L-hexonate dehydrogenase (L-gulonate: NADP oxidoreductase, EC 1.1.1.19), not aldose reductase (Alditol: NADP oxidoreductase, EC 1.1.1.21), which had previously been thought present in erythrocytes. The reduction of glyceraldehyde to glycerol is one of a number of pathways for the metabolism of glyceraldehyde that have been found in red cells and/or other mammalian tissues.

Alcohol Oxidoreductases↗