Vitamin Β12 and Folic Acid Effects on Polyamine Metabolism in Rat Liver

Abstract

Abstract Polyamines, spennine, spermidine and putrescinc, small aliphatic nitrous bases, are normal constituents of microbial, plant and animal cells, where they fulfill an array of physiological roles. Metabolism of polyamines is associated with growth and differentiation of mammalian cells, spermine related to RNA and spermidine to DNA metabolism. Methyl-cobalamin, the coenzyme of methionine synthetase, catalyses the recycling of homocysteine to methionine using 5-methyltctrahydrofolate. By acceleration of methionine biosynthesis these vitamins may influence spermidine and spermine synthesis. Liver tissue is rich in polyamines and it is the place of vitamin B12 and folic acid deposition. Polyamine oxidase (PAO, EC 1.5.3) and diamino oxidase (DAO, EC 1.4.3.6) participate in the process of degradation and interconversion of spermine, spermidine and putrescinc. The idea of our work was to examine the effccts of cobalamin and folic acid on the polyamine metabolism. We have examined the amount of spermine, spermidine and putrescine in liver tissue. At the same time we have examined the activities of PAO and DAO, the catabolic enzymes of polyamine metabolism. Our result suggest that the supplementation of experimental animals with vitamin B12 alone or together with folic acid augmentais spermidine and spermine levels in rat liver, at the same time the amount of putrescine does not change. The application of vitamin cobalamin to experimental animals alone increases PAO; the supplementation of experimental animals with vitamin Β12 together with folic acid causes opposite effect - the decrease of PAO activity. DAO activity significantly decreases under the influence of cobalamin and also with cobalamin and folic acid in combination. Our experimental results indicate the importance of cobalamin and folic acid in polyamine metabolism.