NADPH-forming dehydrogenases in the adipose tissue of obese and nonobese diabetics.

The activity of glucose-6-phosphate dehydrogenase (EC 1.1.1.49) of adipose tissue was markedly decreased, both on a protein and on a fat cell number basis, in nonobese diabetics compared to control subjects, but was unchanged in obese diabetics. Average value in the obese diabetics was about fourfold higher than in nonobese diabetics. On the other hand, the activity of malate dehydrogenase (decarboxylating) (NADP) (EC 1.1.1.40) was reduced by about 50% in both groups of diabetics. These findings suggest that in obese diabetics NADPH-generation in the adipose tissue, necessary for several biosynthetic processes, might be less severely depressed than in lean diabetics.