The rate of uptake of cholesteryl ester from chylomicrons has been determined with the isolated perfused rat heart and both intact and functionally hepatectomized rats. Uptake was found to be proportional to the cholesteryl ester content of the particles. Transfer of cholesteryl ester to other lipoprotein classes of the plasma was negligible under these conditions, and loss of cholesteryl ester from the medium was associated with quantitative recovery in the vascular bed. The uptake mechanism was nonsaturable and independent of the lipoprotein lipase binding site. Compared with receptor-dependent uptake of low density lipoprotein cholesteryl ester by heart endothelium, the chylomicron pathway appears to provide a major proportion of cholesteryl ester cleared from the plasma. Uptake was initially heparin dependent, and cleared lipid was released by 10 microgram/ml of heparin; however, lipid taken up rapidly became heparin resistant and was then hydrolyzed slowly with production of unesterified fatty acid. These results are discussed in the context of the possible role of cholesterol-rich chylomicron remnant lipoproteins in atherogenesis.
C J Fielding
Usage data is cumulative from September 2023 through September 2024.
Usage | JCI | PMC |
---|---|---|
Text version | 108 | 0 |
58 | 20 | |
Scanned page | 318 | 2 |
Citation downloads | 34 | 0 |
Totals | 518 | 22 |
Total Views | 540 |
Usage information is collected from two different sources: this site (JCI) and Pubmed Central (PMC). JCI information (compiled daily) shows human readership based on methods we employ to screen out robotic usage. PMC information (aggregated monthly) is also similarly screened of robotic usage.
Various methods are used to distinguish robotic usage. For example, Google automatically scans articles to add to its search index and identifies itself as robotic; other services might not clearly identify themselves as robotic, or they are new or unknown as robotic. Because this activity can be misinterpreted as human readership, data may be re-processed periodically to reflect an improved understanding of robotic activity. Because of these factors, readers should consider usage information illustrative but subject to change.