【作者】 张明；

【导师】 马爱国；

【作者基本信息】 青岛大学 ， 营养与食品卫生学， 2002， 硕士

【摘要】 目的 通过对农村小学生进行营养调查以了解目前小学生各种营养素的摄入情况和补充抗氧化营养素以探讨其对农村小学生机体抗氧化能力和淋巴细胞DNA损伤的影响。 方法 选择平度市蓝底镇三年级农村小学学生82名，身体健康，年龄在9～11岁之间，随机分为实验组和对照组，每组各41名，实验组小学生每日补充抗氧化营养素片（含维生素A2000IU、维生素E100mg、维生素C500mg、β-胡萝卜素1mg和硒200μg），而对照组则服用相同颜色和包装的安慰剂，实验期为8周，干预前采用24小时膳食回忆法对小学生进行膳食调查。分别于干预前和干预结束时采集血样，分析两组血浆维生素A、维生素E、维生素C、β-胡萝卜素、硒、SOD（超氧化物歧化酶）、GSH-Px（谷胱甘肽过氧化物酶）、MDA（丙二醛）、GH（生长激素）以及淋巴细胞DNA自发性损伤和诱导（5、10、25μmol／LH₂O₂）损伤。 结果 膳食调查显示，小学生膳食中存在蛋白质、核黄素、锌、钙、视黄醇、维生素C和硒的不足。干预后实验组小学生血浆β-胡萝卜素、维生素A、维生素E、维生素C和硒水平明显高于干预前（P₁＜0.01，P₂＜0.01，P₃＜0.01，P₄＜0.01，P₅＜0.01），同时干预后实验组小学生血浆GSH-Px活性均明显高于干预前，而血浆SOD、MDA则明显低于干预前，（P₁＜0.01，P₂＜0.01，P₃＜0.01）；DNA分析结果显示，干预后在两组间小学生淋巴细胞DNA的自发性损伤无差异（P＞0.05），而干预后实验组小学生经5、10、25μmol／LH₂O₂的诱导的淋巴细胞DNA损伤分别明显低于对照组，差异有高度显著性（P₁＜0.01，P₂＜0.01，P₃＜0.01）。 结论 目前，平度农村小学生膳食中存在不同程度的蛋白质、钙、核黄素和锌以及抗氧化营养素维生素A、维生素C和β-胡萝卜素以及硒的不足，应引起足够的重视；对小学生进行抗氧化营养素营养干预，能够明显提高他们血浆抗氧化营养素、GSH-Px水平而明显降低其血浆SOD、MDA的水平，同时表明，补充抗氧化营养素对小学生淋巴细胞的DNA自发性损伤无影响，而对5、10、25μmol／LH202诱导的淋巴细胞DNA氧化损伤有明显的保护作用。更多还原

【Abstract】 Objective The aim of this study was to determine the effect of antioxidant-micro-nutrients supplementation on the antioxidant ability and lymphocyte DNA damage in children.Method 82 healthy children in rural area ,aged 9-11 years were selected and randomized into supplemented group and control group with 41 in each one. A nutrition survey was carried out in each group . In the supplemented group, tablete contains vitamin A 2000IU, (3-carotene 1. 0mg, vitaminE 100mg , vitamin C 500mg and Selenium 200ug were given to each subject every day ,and the tablete for control group has the same size and color as ones of supplemented group for 8 weeks . At the beginning and the end of the supplementation , whole blood was collected in both the supplemented and control groups and its lymphocytes were separated . Damage of DNA was analyzed with a "comet assay",and plasma vitaminA,vitaminE,vitaminC, (3-carotene, Se and superoxide dis-mutase (SOD) ,malondiadehyde (MDA) and glutathione peroxidase (GSH-Px) were determined. Plasma Growth Hormone (GH) was analysed by immunoradiometric assay after 8 weeks supplementation antioxidant-micronutrients.Result Result of nutrition survey indicated that intakes of protein, Riboflavin, vitaminA, vitaminC, (3-carotene,calcium,zint and selenium in diet were lower. Plasma (3-carotene, vitaminA, vitaminE, vitaminC, Selenium increased significantly after eight weeks supplementation with antioxidant-micronutrients (P1<0.01, P2<0. 01, P3 < 0. 01,P4<0. 01, P5<0. 01). Plasma GSH-Px increased from 100. 4 to 161. 7 , while SOD decreased from 108. 8 to 83. 7 and MDA decreased from 7. 2 to 4. 6 , the difference was significant respectively (P1<0. 01, P2<0. 01, P3<0. 01) after eight weeks supplementation with antioxidant-micronutrients in supplemented group. No significant changs were observed in plasma GH compared with pacebo group . Analysis of DNA damage indicated that there was no significant difference in spontaneous damage to DNA (P> 0.05), and A significant decrease in damage of DNA in peripheral lymphocytes after treatment with 5mol/L, 10mol/L, 25mol/L of H2O2 between supplemented group and control group after intervention (P1<0. 01 P2<0. 01, P3<0. 01).Conclusion The intake of antioxidant-micronutrients was lower than RNI except for vitamin E. The intake of calcium,zinand,protein is insufficient compared with RNI in school children aged 9-11 years old in rural area. Antioxidant micronutrients supplementation could effectively improve plasma vitamin A, vitaminC, vitaminE, (3-carotene and selenium , GSH-Px ; decrease SOD and MDA. Supplementating antioxidant micro-nutrients could significantly reduce the damage to DNA in peripheral lymphocytes treated by 5,10^25 /Mmol/L H2O2. It had no effect on spontaneous to DNA damage. There was a rising trend in plasma growth hormone after supplementing with antioxidant- micronutrients, compared with control group ,but the difference was not significant .更多还原