Abstract
Effects of dietary vitamin B_6-deficiency on rat liver glycolytic and glyconeogenetic enzymes, and on fatty acid synthesizing enzymes were investigated. B_6-deficiency of rats was confirmed by the observations of growth retardation, increase in urinary excreted amounts of xanthurenate and microcytosis. In the liver of B_6-deficient rats compared to controls, the levels of activities of glycogen phosphorylase, pyruvate kinase and pyruvate dehydrogenation complex were significantly lowered, while the activities of hexokinase and fructosediphosphate aldolase were increased. The difference of glyceraldehyde-3-phosphate dehydrogenase activity was not significant. Citrate synthase and malate dehydrogenase activities were accelerated and aconitate hydratase activity was decelerated, and citrate was slightly accumulated in deficient rat liver. The activities of phosphoenolpyruvate carboxykinase, triosephosphate isomerase and glycerol-3-phosphate dehydrogenase in deficient group were higher than those in controls. There was no difference in the activity of glycerol kinase between the two groups of rats. The activities of acetyl-CoA carboxylase and fatty acid synthetase were significantly increased by B_6-deficiency. Urinary excreted amounts of acetoacetate in deficient rats were less than in controls.
