高脂膳食诱发家兔血清LPO升高及LDL、VLDL和HDL在活体内的氧化修饰

Oxidative Modification of Serum LDL, VLDL and HDL Induced by Fed on High Cholesterol Diet in vivo in Rabbits *

为探讨高脂膳食对家兔血清过氧化脂质（ＬＰＯ）升高和ＬＤＬ、ＶＬＤＬ，特别是ＨＤＬ氧化修饰的影响。正常对照组（ｎ＝８）喂以普通饲料，高脂实验组（ｎ＝８）用高胆固醇饲料（普通饲料加５％猪油，另每只兔加喂０．５ｇ胆固醇）喂养１２周。兔血清ＬＤＬ、ＶＬＤＬ及ＨＤＬ用密度梯度超速离心法分离得到。ＬＤＬ、ＶＬＤＬ及ＨＤＬ的氧化修饰用琼脂糖凝胶电泳、２３４ｎｍ光吸收及ＴＢＡＲＳ荧光检测进行鉴定。结果显示：高脂实验组兔血清的ＴＣ、ＴＧ和ＬＰＯ均显著高于正常对照组（Ｐ＜０．０１），而ＨＤＬ－Ｃ则显著降低（Ｐ＜０．０５）；同时，高脂实验组的ＬＤＬ、ＶＬＤＬ和ＨＤＬ的电泳迁移率增加，其２３４ｎｍ光吸收及ＬＰＯ含量均显著高于正常对照组（Ｐ＜０．０１）。表明高脂膳食在诱发家兔血清ＴＣ、ＴＧ显著增高的同时，不仅可引起血浆ＬＤＬ及ＶＬＤＬ的氧化修饰。

Many lines of evidence suggest that LDL is oxidized in vivo and that ox LDL is present in the artery wall. But the oxidation of VLDL and HDL in vivo has not been reported yet. A study on effects of high cholesterol diet on oxidative modification of LDL, VLDL and HDL in rabbits was made. The control group ( n =8) was fed on routine diet, and the experimental group ( n =8) on high cholesterol diet (routine diet supplemented with 5% lard, and 0.5g cholesterol a day for each rabbit) for 12 weeks. The serum LDL, VLDL and HDL were isolated by the density gradient ultra centrifugation. The oxidative modification of LDL, VLDL and HDL was identified by agarose gel electrophoresis, absorbance at 234 nm and fluorescence of TBARS. The results showed that serum TC, TG and TBARS in the experimental group were significantly higher than these of the control group ( P <0.01). The electrophoretic mobility of LDL, VLDL and HDL was increased, and absorbance at 234 nm and TBARS of LDL、VLDL and HDL in the experimental group were significantly higher than these of the control group ( P <0.01). These results suggest that not only LDL but also VLDL and HDL were oxidatively modified in vivo in rabbits after fed on high cholesterol diet.