PT  - JOURNAL ARTICLE
AU  - SYSEL, ANNETTE M.
AU  - HORNE, WALTER I.
AU  - STEINER, JÖRG M.
AU  - SUCHODOLSKI, JAN S.
AU  - BAUER, JOSEPH A.
TI  - Serum Folate: A Pharmacodynamic Biomarker of Intracellular Nitrosylcobalamin Activity Following Intravenous Administration in Dogs
DP  - 2012 Oct 01
TA  - Anticancer Research
PG  - 4307--4312
VI  - 32
IP  - 10
4099  - http://ar.iiarjournals.org/content/32/10/4307.short
4100  - http://ar.iiarjournals.org/content/32/10/4307.full
SO  - Anticancer Res2012 Oct 01; 32
AB  - Background/Aim: Cobalamin and folate are interdependent co-factors of the methionine synthase pathway. This study evaluated the effect of intravenously-administered nitrosylcobalamin (NO-Cbl), a vitamin B12 analog, on serum folate concentrations in healthy dogs. Materials and Methods: Four dogs received a 10-mg/kg, 20-mg/kg and 40-mg/kg intravenous bolus dose of NO-Cbl, with a 14-day washout period between doses. Blood samples were collected at baseline and post-dosing, and serum cobalamin and folate concentrations were measured. Results: For each dose, serum cobalamin concentrations were inversely correlated with serum folate concentrations. Spearman rank correlation co-efficient values were −0.976 (10 mg/kg, p<0.0096), and −1.0 (20 mg/kg, p<0.008; 40 mg/kg, p<0.0046). Conclusion: Cellular uptake of NO-Cbl, following intravenous administration exerted a biological effect on folate, similar to that previously described for other vitamin B12 analogs. Serum folate concentration may serve as a pharmacodynamic biomarker of intracellular nitrosylcobalamin activity following intravenous administration.