中文摘要：

选取6周龄雄性昆明种小鼠40只，按体质量随机分成4组：即对照组（正常日粮），高脂日粮组（粗脂肪含量18％），LA组（高脂日粮＋0．05％LA和高脂日粮＋0．1％LA）。小鼠预饲1周后正式饲喂，饲喂5周后进行代谢试验。6周后测定小鼠消化系统自由基水平和肠道黏膜脂肪酶、蛋白酶和淀粉酶活性。结果表明，长期饲喂高脂日粮可显著提高小鼠消化系统自由基水平（P〈O．05），降低肠道淀粉酶和蛋白酶活性（P〈O．05），但肠道脂肪酶活性显著提高（P〈0．05）；小鼠对粗脂肪和粗蛋白消化率降低（P〈O．05），蛋白沉积率降低（P〈0．05）。添加0．05％LA后，能显著降低高脂饲喂小鼠消化系统自南基水平（P〈O．05），提高小鼠对粗脂肪、粗蛋白消化率（P〈0．05），和蛋白沉积率（P〈0．05）；添加0．1％LA可使小鼠全血及系统自由基水平恢复到接近正常水平。由此得出：高脂摄入，增加小鼠消化系统自由基生成，降低消化酶活性、降低机体对营养物质的消化吸收。适宜的LA添加可有效清除小鼠消化系统自由基，提高消化酶活性，提高营养物质的利用率，缓解营养性氧化应激。

英文摘要：

Forty male mice（6-week-old） were randomly assigned into four groups according to the body weight. The control group, the high-fat diet group （crude fat contain 18%）, the LA 1 group （high fat diet with 0.05% LA） and the LA 2 group （high-fat diet with 0.1% LA）. After 5 weeks feed, the metabolism experiment was carried out. 6 weeks later, the level of the free radi- cal in organizations of the digestive system and the activity of protease, lipase and amylase in the digestive tract were detected. The results showed that feeding the mice with high-fat diet in longterm could improve the level of the free radical in the mice digestive system （P〈0.05） and the activity of the lipase in the digestive tract significantly （P〈0.05）, decrease the activity of the protease and amylase （P〈0.05）, decline the digestibility of the fat, protein （P〈0.05） and the sedimentation rate of the protein （P（0.05）. Adding 0.05% LA into the high fat diet could incline the level of the free radical remarkably, enhance the activity of these enzymes and digestibility of the fat, protein and the sedimentation rate of the protein（P〈0.05）. Adding 0.1% LA into the high-fat diet can recover the level of free radical up to normal level. It was concluded that the high fat diet could significantly increase the production of the free radical in the mice digestive system, decrease the activity of the digestive enzymes and the absorption of the nutrition. While adding the optimum LA into the high-fat diet could get rid of these disadvantage and relieve the oxidative stress.