Intestinal apoB synthesis, lipids, and lipoproteins in chylomicron retention disease.

摘要: Chylomicron retention disease is characterized by fat malabsorption, hypocholesterolemia, normal fasting triglycerides, and marked intestinal steatosis despite the presence of both plasma apoprotein B. The defect remains unknown but presumably involves synthesis or secretion chylomicrons. present investigation examines this hypothesis studying biosynthesis chylomicrons in cultured jejunal explants defining quantitative qualitative abnormalities lipids circulating lipoproteins. Following 2-3 years a low diet supplemented with medium chain six patients chylomicron had significantly higher triglyceride (TG) levels coupled decrease free (FC) esterified cholesterol (EC) as well essential fatty acids phospholipids (PL) when compared to healthy controls. total was largely accounted for density (LDL) high lipoprotein (HDL) cholesterol. VLDL LDL were diminished percentage CE an increase TG while HDL contained relatively more FC PL less CE. diameter larger whereas those smaller than Jejunal explants, incubated [14C]palmitate, capable TG, diglycerides, PL, These lipids, however, except retained tissue could not be secreted into culture medium. Incubation biopsies [3H]leucine [14C]mannose resulted protein reduced glycosylation. apoB-48 confirmed immunoblot using 2D8 antibodies. data suggest that results from disorder final assembly mechanism their exocytosis.