Mayumi Shibuya

Effect of diabetes on vitamin B6 requirement in experimental animals.

Aim: 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.

Effect of vitamin B-6 nutrition and diabetes on vitamin B-6 metabolism

Vitamin B-6 content, some B-6 dependent enzymes, and alkaline phosphatase were examined in rat tissues subjected to different nutritional conditions and treated with or without streptozotocin. There was almost no B-6 in the plasma from the nutritionally deficient rat. The ratio of pyridoxal phosphate to pyridoxal in the plasma was decreased by injection of streptozotocin and was inversely correlated to an increase in alkaline phosphatase activity. Vitamin B-6 content in the liver of the nutritionally deficient rats was approximately 50% of that of the controls and this decrease correlated to aspartate aminotransferase activity in this tissue. Vitamin B-6 content in the skeletal muscle from the nutritionally deficient rats decreased to less than 20% of the control level and this decreased level correlated to the glycogen phosphorylase activity in this tissue.