Effects of dietary n-3 PUFA and cholesterol interaction on hamster LDL oxidation in vitro and VLDL lipolysis in vitro

• Main Authors: Yao, Fu Zhou, 姚富洲
• Other Authors: Huang, Bo Chao
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/32387740046656900390

碩士 === 國立臺灣大學 === 生化學研究所 === 84 === Previous studies had revealed that PUFA is more susceptible to oxidation than saturated fatty acids, but the studies about the effect of cholesterol on LDL oxidation is still not clear. In order to explore the effects of n-3 PUFA and cholesterol on LDL oxidation in vitro, male hamsters about 80g were divided into four groups and fed semisynthetic diets containing 15% protein for 3 weeks. The fat of the experimental diet is a mixture of coconut oil, soybean oil and fish oil by different propotion and P/S is equal to 1. When hamsters were sacrified, we used ultracentrifuge isolate lipoproteins. After dialyzed against PBS, LDL was oxidized with 5 mM Cu2+ in vitro. Besides with the formation of TBARS, conjugated diene and electrophoretic mobility assay to test the susceptibility of LDL to Cu2+-catalyzed oxidation, we also analyze the content of a-tocopherol and composition of fatty acid of LDL. No matter with or without cholesterol supplementation in the diets, the n-3 PUFA content in the LDL of n-3 PUFA group is obviously higher than that in the LDL of the n-6 PUFA group, but the linoleic acid (C 18:2) content of the LDL of n-3 PUFA group is obviously lower than that of n-6 PUFA group. Besides, the a-tocopherol content of LDL reveals that the LDL of n-6 PUFA+0.1%C group has the highest content of a-tocopherol, the next is the LDL of n-6 PUFA group and the LDL of n-3 PUFA group has the lowest content of a-tocopherol. Thus the results suggest that the LDL of n-3 PUFA group is more susceptible to oxidation than that of n-6 PUFA group is due to the change of fatty acid composition or the content of a-tocopherol of LDL reduced in LDL of n-3 PUFA fed hamsters. The supplementation of dietary cholesterol may result in change of the a-tocopherol content in LDL or the cholesterol may function as antioxidant .