Figure 4.

Feeding of a vitamin B₂-deficient diet induced glycolate accumulation in plasma from mice. (A,E) Study design for Experiments 4 and 5. Mice were fed a control diet, VB- diet, or VB2-deficient (VB2-) diet for 2 weeks with or without VB2 supplementation (6 μg/mL flavin mononucleotide sodium salt solution in distilled water). (B,F) Average plasma VB2 concentration in each of the three groups. (C,G) Relative plasma concentration of GA. (D) Spearman’s rank correlation coefficients between plasma VB2 concentration and plasma GA levels (r² = 0.42, p = 0.03). (H) Relative GA oxidase (GO) activity in the liver. (I) Spearman’s rank correlation coefficients between relative hepatic GO activity and plasma GA levels (r² = 0.45, p = 0.01). ANOVA was used to determine differences in each group (n = 3–4 in Experiment 4 and n = 4–5 in Experiment 5). Different letters indicate p < 0.05 and N.S. represents no significant difference among the groups.