Arginine-derived hydroimidazolone residues and corresponding free adducts in plasma of SD and SDT rats at different ages. (A) Specimen chromatograms of MG-H1- and AP-free aducts in plasma of SDT rats at 8 and 24 weeks, (B) specimen chromatograms of G-H1-, CML-, and CEL-free adducts in plasma of SDT rats at 8 and 24 weeks, (C) MG-H1 residue, (D) MG-H1-free adduct, (E) G-H1 residue, and (F) G-H1-free adduct. Data are mean ± SEM (n = 4). Hollow bars, control SD rats; solid bars, SDT rats. Significance: statistical differences within group were evaluated using one-way analysis of variance (ANOVA), different letters represent the statistical differences at P < 0.05 among the means in each group by Dunnett’s test for multiple comparisons. *indicates significance of difference with respect to age-matched SD control rats by Student’s t-test, where one, two, and three symbols reflect *P < 0.05, **P < 0.01, and ***P < 0.001, respectively.