Factors affecting formiminoglutamic acid excretion in vitamin B12 deficiency

• Published in: Biochemical journal 1970-02, Vol.116 (4), p.681-688
• Main Authors: Marston, Hedley R., Allen, Shirley H.
• Format: Article
• Language: English
• ISSN: 0306-3283; 0264-6021; 1470-8728
• DOI: 10.1042/bj1160681

1. Formiminoglutamic acid, a product of the catabolism of histidine, is excreted in abnormally large amounts in the urines of vitamin B12-deficient rats and of vitamin B12-deficient sheep; the excretion is reduced to negligible amounts after administration of vitamin B12. 2. After administration of certain methyl donors to vitamin B12-deficient rats or sheep urinary excretion of formiminoglutamic acid is temporarily decreased. 3. Irrespective of the pteroylglutamic acid status of the animals neither vitamin B12-deficient rats nor vitamin B12-deficient sheep have the ability to deal efficiently with histidine. 4. In sheep, urinary excretion of formiminoglutamic acid is increased after administration of aminopterin; treatment with pteroylglutamic acid restores the ability of the animal to deal with the catabolic products of histidine. 5. The possible functions of vitamin B12 and methionine in relieving a virtual deficiency of pteroylglutamic acid are discussed.