出版社：American Society for Biochemistry and Molecular Biology
摘要：Fatty acids (FA) were added to differentiating chick adipocytes to study their effects on the synthesis and secretion of avian lipoprotein lipase (LPL). Oleate (18:1n-9), eicosapentaenoate (EPA, 20:5n-3), and linoleate (18:2n-6) were complexed to fatty acid-free bovine serum albumin (BSA) and separately added to cells in RMPI-1640 media containing 0.5% delipidated hen serum. LPL secretion in the presence of 10 U/ml heparin was used as a means of estimating LPL synthesis. FA from 50 microM to 165 microM depressed LPL secretion for cells exposed to 20:5n-3 and 18:2n-6. The decrease in adipocyte LPL secretion was only observed with chronic administration of FA. In other experiments, the rate of LPL synthesis was estimated by incorporation of radiolabel (Tran 35S-label) in cells exposed to 50 microM FA. Total radioactivity incorporated into LPL, expressed as a percentage of total trichloroacetic acid (TCA)-precipitable radioactivity, was not affected in cells fed 18:1n-9 but was significantly decreased for cells fed 20:5n-3 (45%) or 18:2n-6 (67%) relative to controls given equimolar BSA (33 microM). Abundance of LPL message in similarly treated cells also decreased for cells incubated with 20:5n-3 or 18:2n-6 (35%) relative to controls and 18:1n-9-treated cells. A decrease in adipocyte LPL secretion was also observed with administration of lipoprotein (d
