Effect of diabetes on vitamin B6 requirement in experimental animals.

Abstract

In the diabetic state, energy must be supplied mainly by amino acids and fat; therefore the metabolic processes are very similar to those of animals fed a high-protein diet. Vitamin B6-dependent enzymes, which are highly involved in amino acid metabolism, are important in diabetics. We investigated vitamin B6 content, and aspartate aminotransferase and glycogen phosphorylase activities, in several tissues of streptozotocin-induced diabetic and control rats. The rats were fed a vitamin B6-free diet and administered an equivalent amount of pyridoxine based on body weight. Vitamin B6 content in all tissues examined, except for the liver, was lower in the diabetics than in controls. Aspartate aminotransferase activity was higher in the liver of diabetics than in the controls, but not in the other tissues. Glycogen phosphorylase activity in the gastrocnemius muscle of diabetics decreased to two-thirds of the control level. These data might indicate that diabetic animals should have a higher intake of vitamin B6 because a diabetic state can lead to a vitamin B6-deficiency.