Lykkesfeldt Jens, Trueba Gilberto Perez, Poulsen Henrik E, Christen Stephan
Section of Biomedicine, Department of Veterinary Pathobiology, Faculty of Life Sciences, University of Copenhagen, 9 Ridebanevej, DK-1870 Frederiksberg C, Denmark.
Br J Nutr. 2007 Dec;98(6):1116-9. doi: 10.1017/s0007114507787457.
Neonates are particularly susceptible to malnutrition due to their limited reserves of micronutrients and their rapid growth. In the present study, we examined the effect of vitamin C deficiency on markers of oxidative stress in plasma, liver and brain of weanling guinea pigs. Vitamin C deficiency caused rapid and significant depletion of ascorbate (P < 0.001), tocopherols (P < 0.001) and glutathione (P < 0.001), and a decrease in superoxide dismutase activity (P = 0.005) in the liver, while protein oxidation was significantly increased (P = 0.011). No changes in lipid oxidation or oxidatively damaged DNA were observed in this tissue. In the brain, the pattern was markedly different. Of the measured antioxidants, only ascorbate was significantly depleted (P < 0.001), but in contrast to the liver, ascorbate oxidation (P = 0.034), lipid oxidation (P < 0.001), DNA oxidation (P = 0.13) and DNA incision repair (P = 0.014) were all increased, while protein oxidation decreased (P = 0.003). The results show that the selective preservation of brain ascorbate and induction of DNA repair in vitamin C-deficient weanling guinea pigs is not sufficient to prevent oxidative damage. Vitamin C deficiency may therefore be particularly adverse during the neonatal period.
由于新生儿的微量营养素储备有限且生长迅速，他们特别容易受到营养不良的影响。在本研究中，我们检测了维生素C缺乏对断奶豚鼠血浆、肝脏和大脑氧化应激标志物的影响。维生素C缺乏导致肝脏中抗坏血酸盐（P < 0.001）、生育酚（P < 0.001）和谷胱甘肽（P < 0.001）迅速且显著地消耗，超氧化物歧化酶活性降低（P = 0.005），而蛋白质氧化显著增加（P = 0.011）。在该组织中未观察到脂质氧化或氧化损伤DNA的变化。在大脑中，情况明显不同。在所测量的抗氧化剂中，只有抗坏血酸盐显著减少（P < 0.001），但与肝脏相反，抗坏血酸盐氧化（P = 0.034）、脂质氧化（P < 0.001）、DNA氧化（P = 0.13）和DNA切口修复（P = 0.014）均增加，而蛋白质氧化减少（P = 0.003）。结果表明，在维生素C缺乏的断奶豚鼠中，大脑抗坏血酸盐的选择性保留和DNA修复的诱导不足以防止氧化损伤。因此，维生素C缺乏在新生儿期可能特别有害。
