| dc.contributor.author | Grandmaison, Paul Andrew. | en_US |
| dc.date.accessioned | 2014-10-21T12:34:10Z | |
| dc.date.available | 1999 | |
| dc.date.issued | 1999 | en_US |
| dc.identifier.other | AAINQ49264 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55644 | |
| dc.description | Hep G2 cells were used to investigate the relative contribution of exogenous fatty acids and mobilization of stored triacylglycerol (TAG) for apo B-containing lipoprotein (LpB) assembly, which may influence plasma concentrations of atherogenic lipoproteins. TAG-rich LpB of LDL size were isolated from culture media by heparin chromatography following incubations with oleate or myristate. Percent composition of lipid classes was similar after oleate or myristate incubations; however, lipid molecular species were skewed towards species containing the exogenous fatty acid. The isolation of LpB was important for metabolic studies since 22--28% of total TAG in the media and 31--55% of total cholesteryl esters in the media were not associated with apo B. | en_US |
| dc.description | The relative use of exogenous fatty acid versus stored TAG in LpB assembly was studied by analysis of cellular and LpB lipid molecular species. Cells were incubated with oleate for 18 hours to define the molecular species of cellular lipid and chased with myristate for increasing periods of time or with cerulenin for two sequential chases. Myristate-containing lipid species were rapidly secreted in LpB and were secreted at a constant rate for up to 12 hours. Stored oleate-containing TAG species continued to be secreted throughout myristate chases, although at a decreasing rate. Cells secreted more TAG mass after oleate incubation followed by myristate chases than when chased with oleate whereas cells chased with oleate accumulated more cellular TAG mass compared to cells chased with myristate. Thus, stimulation of TAG secretion and TAG storage may be independent events. Cerulenin inhibited the secretion of LpB lipid mass when cells were chased without fatty acid; however, cerulenin increased secreted LpB lipid mass when cells were incubated with fatty acid and only had minor effects on TAG molecular species. The minimum percentage of LpB TAG that was consistent with mobilizing cellular lipid without modification or via a total or partial hydrolysis/re-esterification cycle was <23%. Esterification of exogenous fatty acid for LpB assembly was consistent with a minimum of 41% of the LpB TAG. Therefore, esterification of exogenous fatty acid was the primary source of TAG for the assembly of LpB in Hep G2 cells. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 1999. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Biology, Molecular. | en_US |
| dc.subject | Biology, Cell. | en_US |
| dc.title | The role of exogenous fatty acids and endogenous lipid in the synthesis and secretion of apolipoprotein B(100)-containing lipoproteins in the Hep G2 cell line. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
