The metabolism of glucose by the Embden-Meyerhof, pentose cycle and citric acid cycle pathways was determined in human polymorphonuclear leucocytes from control subjects and from patients with diabetes mellitus, with and without hypercholesteremia.
In controls over 85 per cent of glucose uptake was metabolized to lactic acid by the Embden-Meyerhof pathway; about 5 per cent of glucose uptake was recovered as Co2, mostly from oxidation in the pentose cycle. Minimal citric acid cycle activity, a finding which correlated well with the paucity of mitochondria in the leucocyte, was shown by the slight and similar degree of oxidation of pyruvate and acetate.
Glucose metabolism in leucocytes from diabetics differed in two respects. The per cent of glucose uptake oxidized in the pentose cycle was increased in leucocytes from all diabetics. In the insulin-treated diabetics glucose uptake and lactic acid formation were similar to controls. In contrast, glucose uptake and lactic acid formation were reduced in leucocytes from adult, latent, hypercholesteremic diabetics. Pyruvate and acetate oxidation was similar in diabetics and controls. Thus, in terms of leucocyte metabolism, hypercholesteremia in the human diabetic was correlated with reduced glycolysis and not with reduced pentose cycle activity.