Effects of fatty acids on lipid metabolism in hepatocytes, plasma lipids and oxidative modification of low density lipoprotein

• Main Authors: Wu,Wen-Huey, 吳文惠
• Other Authors: Huang, Po-Chao
• Format: Others
• Language: zh-TW
• Published: 1994
• Online Access: http://ndltd.ncl.edu.tw/handle/23270325723595718914

博士 === 國立臺灣大學 === 生化學研究所 === 82 === In order to investigate the role of liver in the regulation of plasma lipids by fats and cholesterol(CHOL), the cultured hepatocytes were enriched with a certain fatty acid by supple- menting Myr, Pal, Ole,Lin or EPA complexed with BSA in a molar ratio of 600:150 to the medium for 24 hours or through feeding the rats 10% (w/w) saturated(SF), monounsaturated (MUF),poly- unsaturated fat (MUF) or fish oil (FO) for 5 weeks before isolation of hepatocytes. CHOL enrichment was through diet in both protocols. When the hepatocytes were isolated from rats fed low fat (chow) diet, CHOL supplementation increased the secretion of VLDL-apo B and -Chol,but in high fat diet, CHOL decreased that of VLDL-apo B and -TG . When the hepatocytes were modified by medium fatty acids, the secretion and storage of lipid were not much different among groups except that EPA inhibited and Pal stimulated VLDL-TG and CHOL secretion. When fatty acids were given through diets, the hepatocytes of MUF group stored the highest amount of TG and CHOL. When CHOL was given simultaneously,VLDL-TG,.-CHOL, and -apo B secreted in a highly correlated manner and in the order of SF>PUF>MUF>FO.The secretion of medium apoA-I by hepatocytes was lower in low fat diet and FO diet compared to other groups. When hepatocytes were enriched with CHOLl, the secretion of apo A-I decreased in all groups except SF group.PUF group secreted less apo A-I than SF group and MUF group between these two without significant difference. The activity of LDL receptor was examined in rabbit hepatocytes enriched with a certain fatty acid by medium supple- mentation. Pal suppressed the binding and uptake of rabbit or human LDL by rabbit hepatocytes with or without CHOL feeding. EPA and Lin stimulated the binding and uptake but EPA suppressed the degradation of LDL.