Inhibitor of Glucose-6-phosphate Dehydrogenase Activity in the Erythrocytes of Macaca nemestrina Monkeys

Abstract

DATA are available on the activity of G-6-P dehydrogenase in the erythrocytes of different species of monkeys¹, using the dye decoloration method of Motulsky and Campbell². In M. nemestrina the test did not clear after 5 h while in four other species the decoloration time was normal. We have further examined this phenomenon. Blood of seven individuals of M. nemestrina, seven M. mulatta and three Presbytis entellus in acid citrate dextrose inosine (ACDI) was examined. In agreement with earlier findings, M. nemestrina is the only species in this group which gave abnormal results. When fresh haemolysate (±14 g per cent) of M. nemestrina was used in the test instead of erythrocytes, some haemolysates cleared within normal time, others did not. In contrast, hundreds of normal human haemolysates gave normal results. Starch gel electrophoresis of the G-6-P dehydrogenase³ showed a large amount of enzyme in all the monkey haemolysates, including those of M. nemestrina (Fig. 1). The mobility of the enzyme is similar to the fast-moving A type of human G-6-P dehydrogenase. Some factor must therefore have been present which prevented reduction of the dye in the test system, either by inhibition of the activity of G-6-P dehydrogenase or by continuous oxidation of the brilliant cresyl blue.