| Summary: | 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.
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