食物脂肪对大鼠DNA氧化性损伤的影响

Effects of Dietary Fat on Oxidative Damage of DNA in Rats

目的探讨摄入不同脂肪含量食物对大鼠DNA氧化性损伤作用的影响。方法45d龄F344雌性大鼠被喂饲含5%玉米油的AIN-93G饲料12d后,随机分为5组,每组10只。分别用含3%、5%、10%、15%和20%玉米油的饲料喂养20周。观察血液和乳腺组织中5-羟甲基-2-脱氧尿苷(5-OHmdU)含量的改变。结果血液中5-OHmdU水平随食物中脂肪含量增加,而乳腺中5-OHmdU水平于10%食物脂肪含量时到达高峰,随后呈平台形态。结论血液5-OHmdU水平可以作为脂肪摄入导致的DNA氧化性损伤的生物标志物,而乳腺中5-OHmdU水平的变化提示中等水平的食物脂肪摄入即可导致乳腺组织中DNA氧化性损伤发生。

Objective To explore the effects of different levels of dietary fat on oxidative damage of DNA in rats.Methods 45day-aged F344female rats were supplied with feed containing5%corn oil for12days,then were averagely divided into5groups,ten rats per group.Above5groups were fed by3%,5%,10%,15%and20%corn oil feed for20weeks respectively.The contens of5-hydroxymethyl-2-deoxyuridine(5-OHmdU)in blood and mammary tissue were determined.Results The con-tents of5-OHmdU in blood in creased with the increase of content s of dietary fat in feed.The contents of5-OHmdU in mammary tissue reached the peak in group fed with10%dietary fat then showed a plateau-type effect.Conclusion5-OHmdU levels in blood appeared to be a biomarker of oxidative DNA damage due to dietary fat intake.However,5-OHmdU levels in mammary tissue suggested that the oxidative DNA damage might appear at the middle levels of fat intake.