Table 2.
Biochemical parameters of plasma, residual cortex and the adrenal glands.
| Group/Marker | Ctrl (n = 19) | Def (n = 19) | Sev_Def (n = 19) | One-Way ANOVA or Kruskal-Wallis Test | |
|---|---|---|---|---|---|
| Plasma | VitC (μM) * | 43.3 ± 8.5 a | 4.4 ± 0.91 b | 2.2 ± 0.46 c | p < 0.0001 |
| DHA (%) # | 1.9 ± 2.0 | 3.0 ± 3.5 | 2.8 ± 3.5 | NS | |
| BH4 (nM) | 68.3 ± 8.3 a | 47.5 ± 10.1 b | 40.4 ± 6.4 c | p < 0.0001 | |
| BH2/BH4 ¤ | 0.18(0.16; 0.22) a | 0.31(0.25; 0.43) b | 0.36(0.33; 0.41) b | p < 0.0001 | |
| α-tocopherol (μM) | 2.7 ± 0.8 | 2.5 ± 0.7 | 2.5 ± 0.7 | NS | |
| γ-tocopherol (μM) | 0.1 ± 0.06 | 0.1 ± 0.05 | 0.09 ± 0.04 | NS | |
| MDA(μM) | 1.0 ± 0.1 | 1.1 ± 0.2 | 1.1 ± 0.2 | NS | |
| Residual cerebralcortex | VitC (nmol/g) | 1320 ± 254.6 a | 753.2 ± 70.7 b | 393.6 ± 91.3 c | p < 0.0001 |
| DHA (%) ¤ # | 2.2(1.6; 2.6) | 1.6(0.1; 1.9) b | 0.0(0; 0.3) c | p < 0.0001 | |
| GSH (nmol/g) | 1244 ± 113.7 | 1247 ± 79.0 | 1244 ± 76.4 | NS | |
| GSSG (%) | 3.7 ± 1.9 | 4.0 ± 1.8 | 3.9 ± 1.1 | NS | |
| SOD (U/g) | 235 ± 54.0 | 232 ± 63.3 | 229 ± 79.9 | NS | |
| MDA (nmol/g) ¤ | 165.9(135.1; 200.1) | 169.5(140.7; 203.6) | 200.8(152.5; 254.9) | NS | |
| α-tocopherol (nmol/g) | 12.6 ± 3.1 | 11.9 ± 3.3 | 11.9 ± 1.6 | NS | |
| γ-tocopherol (nmol/g) | 0.6 ± 0.2 | 0.6 ± 0.2 | 0.6 ± 0.2 | NS | |
| Adrenal glands | VitC (nmol/g) | 9571 ± 1951 a | 3353 ± 1606 b | 2554 ± 2344 b | p < 0.0001 |
| DHA (%) | 3.5 ± 1.9 a | 4.8 ± 2.0 a b | 5.7 ± 2.1 b | p = 0.0052 | |
| GSH (nmol/g) | 1531 ± 107 a | 1670 ± 172 b | 1745 ± 180 b | p = 0.0004 | |
| GSSG (%) | 2.1 ± 1.5 | 1.8 ± 1.5 | 2.1 ± 1.7 | NS | |
| SOD (U/g) | 180 ± 55.6 | 158 ± 52.0 | 173 ± 57.3 | NS |
Despite a clear influence of diet on vitamin C levels in plasma, cortex and adrenal glands, only the adrenal glands showed sign of increased oxidative stress. One-way ANOVA or Kruskal–Wallis with Tukey’s or Dunn’s multiple comparison tests, n = 19, mean ± SD for parametric analysis, if non-parameteric: median (25%; 75% quartiles) are reported. * Denotes log transformed data. ¤ Denotes nonparametric ANOVA. # Denotes truncated data. Different superscript letters denotes differences between groups. BH2: Dihydrobiopterin, BH4: Tetrahydrobiopterin, Ctrl: Control animals, Def: Vitamin C deficient animals, DHA: Dehydroascorbate, GSH: Glutathione, GSSG: glutathione disulfide, MDA: Malondialdehyde (MDA), NS: Not significant, Sev_def: Severely vitamin C deficient animals, SOD: Superoxide dismutase, VitC: Vitamin C. Tissue levels are shown as amount per gram tissue.