Fig 7. Brain kynurenine metabolism is altered by the HD genotype and NIS.

Mouse pups were supplemented with iron from postnatal days 10–17. KP metabolite levels were measured in the cortex (A-D) and striatum (E-H) at 14 weeks of age and are presented per milligram of soluble brain protein. A. Cortical tryptophan levels were unchanged. B. Cortical kynurenine was increased in iron-supplemented WT mice and in HD mice relative to control WT mice. C. HD mice had elevated 3-HK in the cortex. D. Kynurenic acid levels in the cortex were unchanged as a result of iron supplementation or the HD genotype. E. Striatal tryptophan levels were unchanged. F. Kynurenine was increased in the striatum of iron-supplemented WT mice and in HD mice relative to control WT mice. G. Striatal 3-HK was elevated by iron supplementation in WT mice and by the HD genotype H. Iron-supplemented HD mice had decreased striatal kynurenic acid compared with iron-supplemented WT mice. I. Cortical kynurenine/tryptophan (kyn/trp) ratios were increased in iron-supplemented WT and in HD mice. J. The kyn/trp ratio in the striatum was increased by iron supplementation and in HD mice relative to control WT mice. K. Iron-supplemented HD mice had increased 3-hydroxykynurenine/kynurenic acid (3-HK/kyna) ratios in the cortex compared with iron-supplemented WT mice. L. Striatal 3-HK/kyna ratios were increased by the HD only in the presence of iron supplementation. A-L. Data are shown as the mean ± SE. n = 10.