Effect of methionine on the metabolism of formate and histidine by rats fed folate/vitamin B-12-methionine-deficient diet.
The metabolism of formate and histidine were compared in rats and in perfused livers of rats on diets deficient in vitamin B-12, methionine, and folic acid. Excretion of formate and formiminoglutamic acid, and the oxidation of [2-14C]histidine and [14C]formate to 14CO2 were measured. Liver folate levels decreased to 40% of normal on the vitamin B-12- and methionine-deficient diets but the rate of oxidation of histidine to CO2 in the whole animal decreased to 15% of normal. This indicated a reduction in the metabolic activity of the liver folates in vitamin B-12deficiency. Comparison of formate and histidine catabolism in folic acid deficiency showed that the oxidation of histine was decreased to 5% of normal but formate oxidation was decreased to only 30% of normal. This indicates that 25% of formate oxidation normally proceeds by a non-folate-dependent pathway.
D000818:Animals; D002245:Carbon Dioxide; D002374:Catalase / Q000378:metabolism; D005492:Folic Acid / Q000627:therapeutic use; D005494:Folic Acid Deficiency / Q000188:drug therapy / Q000378:metabolism*; D005561:Formates / Q000378:metabolism*; D005565:Formiminoglutamic Acid / Q000652:urine; D006639:Histidine / Q000378:metabolism*; D008099:Liver / Q000378:metabolism; D008297:Male; D008715:Methionine / Q000172:deficiency* / Q000627:therapeutic use; D010084:Oxidation-Reduction; D051381:Rats; D014805:Vitamin B 12 / Q000627:therapeutic use; D014806:Vitamin B 12 Deficiency / Q000188:drug therapy / Q000378:metabolism*
D005561:Formates; D002245:Carbon Dioxide; D006639:Histidine; D005565:Formiminoglutamic Acid; D005492:Folic Acid; D008715:Methionine; D002374:Catalase; D014805:Vitamin B 12