The Effect of dl-Methionine,Vitamin B 12,and Thyroid Powder on Metabolism of Formiminoglutamic Acid in Rats 1

Abstract

Summary

The effect of methionine and folic acid on metabolism of FIGLU was studied in liver homogenate of rats fed diets which were either deficient or supplemented with vitamin B₁₂, thyroid powder, and methionine. The increased levels of FIGLU in urine and liver caused by either vitamin B₁₂ deficiency or by feeding thyroid powder and absence of FIGLU accumulation in urine and liver by administration of methionine in diet confirmed the previously reported results. The addition of methionine either singly or in combination with tetrahydrofolic acid or with 5,10- methenyltet-rahydrofolic acid to the liver homogenate of vitamin B₁₂-deficient and/or thyroid-fed rats did not affect the rate of FIGLU breakdown in liver homogenate.