Effect of pyridoxine deficiency and prednisolone on beta-alanine-oxoglutarate aminotransferase and D-3-aminoisobutyrate aminotransferase in rat liver and kidney.

Abstract

beta-Alanine-oxoglutarate aminotransferase (beta-Ala-TI) was found to be distributed mainly in liver, brain, kidney, and testis (decreasing order of enzyme activity in the rat). D-3-Aminoisobutyrate aminotransferase (beta-Ala-T II) was distributed in kidney and liver. Both beta-Ala-T I and beta-Ala-T II were localized in the mitochondrial fraction in rat kidney. beta-Ala-T I in the liver of rats fed on pyridoxine-deficient or control diets was induced by injecting with prednisolone, while beta-Ala-T II in the liver of these rats was unaffected by prednisolone injection. The activities of beta-Ala-T I and beta-Ala-T II in the liver of rats fed on pyridoxine deficient diet did not change. However, in kidney, pyridoxine deficiency suppressed both enzyme activities, while treatment with prednisolone did not induce either enzyme. The ratios of the apo- to holo-enzyme for beta-Ala-T I and beta-Ala-T II in control rat kidney were 1.04 and 0.11, respectively. The values increased to 2.69 and 1.53, respectively, in pyridoxine-deficient rat kidney. These experiments indicate that pyridoxine deficiency and prednisolone affect the activities of beta-alanine degrading enzymes, but that the degree is different between liver and kidney.