HDL are secreted from the liver and mucosa of the small intestine. However, there are several indications that part of HDL could originate from chylomicrons and VLDL. In order to get further data on the origin of HDL, the effects of the in vivo and in vitro chylomicron lipolysis have been studied in two sibs affected with primary familial type V hyperlipoproteinemia. In vivo lipolysis, as promoted by heparin injection, resulted in a marked increase of HDL, as evaluated by analytical ultracentrifugation. In vitro lipolysis of isolated chylomicrons, as produced by purified lipoprotein lipase, gave the following results: formation of lamellar structures on chylomicron surface, as observed by transmission electron microscopy; cholesterol crystal formation on the chylomicron surface, as observed by scanning electron microscopy; and HDL-like particle formation. These particles, separated in preparative ultracentrifuge at d 1.063-1.210 from LPL-incubated chylomicrons, contained apo A-I, A-II, C-peptides, free cholesterol, phospholipids (phosphatidyl choline), minor amounts of cholesteryl esters and traces of triglycerides. By transmission electron microscopy, spherical particles of 100 Å and 200 Å diameter were observed.
|Translated title of the contribution||Formation of α-lipoproteins (HDL) from chylomicrons in phenotype V hyperlipoproteinemia|
|Number of pages||25|
|Journal||Giornale della Arteriosclerosi|
|Publication status||Published - 1981|
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine