title: Oxidation of 5-methyltetrahydrofolate in cobalamin-inactivated rats.
abstract: Rats were exposed to nitrous oxide, which inactivates cob(I)alamin (Cbl). As in air-breathing rats methionine administration led to the conversion of hepatic 5-methyltetrahydrofolate (MeH4 folate) into formyltetrahydrofolate. The recovery of MeH4 folate levels in liver after its oxidation initiated by methionine was noted and the rate compared with that for air-breathing rats. Oxidation of MeH4 folate was less complete and occurred more slowly in Cbl-inactivated rats as compared with controls. However, recovery of MeH4 folate levels was more rapid in Cbl inactivation. S-Adenosylmethionine did not produce a significant change in MeH4 folate levels in Cbl-inactivated rats, whereas it did so in air-breathing animals.
authors.affiliation: M.R.C. Clinical Research Centre, Northwick Park Hospital, Harrow, Middx., U.K.
authors.forename: M
authors.initials: M
authors.lastname: Lumb
authors.forename: R
authors.initials: R
authors.lastname: Deacon
authors.forename: J
authors.initials: J
authors.lastname: Perry
authors.forename: I
authors.initials: I
authors.lastname: Chanarin
mesh_terms: D000818:Animals; D005575:Formyltetrahydrofolates / Q000378:metabolism; D008715:Methionine / Q000494:pharmacology; D010084:Oxidation-Reduction; D051381:Rats; D011919:Rats, Inbred Strains; D012436:S-Adenosylmethionine / Q000494:pharmacology; D013763:Tetrahydrofolates / Q000378:metabolism*; D014805:Vitamin B 12 / Q000378:metabolism*
chemical_list: D005575:Formyltetrahydrofolates; D013763:Tetrahydrofolates; D012436:S-Adenosylmethionine; D008715:Methionine; D014805:Vitamin B 12; C005984:5-methyltetrahydrofolate