Role of Vitamin B12 in Nucleic Acid Metabolism I. Hemoglobin and Liver Nucleic Acid Levels in the Rat

Abstract

The growth rate, liver DNA and RNA levels, and liver regeneration ability after partial hepatectomy of rats fed an iodinated casein basal diet deficient in vitamin B12 were lower than those of supplemented controls. In subsequent experiments, an uncomplicated vitamin B12 deficiency was produced in rats born from mothers fed the vitamin B12-deficient diet without iodinated casein during gestation and lactation. The growth rate and liver nucleic acid composition of these rats fed the basal ration were significantly lower than those for the controls fed supplemented rations. A syndrome characterized by presence of porphyrin whiskers and scaly feet was also noted in the deficient rats. The addition of dried liver to the non-iodinated casein ration did not improve the growth-promoting activity of vitamin B12 when the latter was present at a level of 50 μg/kg ration. However, inclusion of 4 or 10% of dried liver in the diet of the female rats, and 10% of liver in the diet of male rats, significantly increased the hemoglobin content of the blood (P < 0.05) as compared with that observed when the vitamin B12-deficient diet was fed. The significance and implications of these findings were discussed.