Sparks, Daniel,Stamler, Christopher John.2009-03-232009-03-2320022002Source: Masters Abstracts International, Volume: 41-02, page: 0545.9780612727946http://hdl.handle.net/10393/6139http://dx.doi.org/10.20381/ruor-14704To examine the role that lipoprotein surface charge plays in cholesterol metabolism in vivo, we characterized the effects of an intravenous injection of an uncharged phospholipid (phosphatidylcholine, PC (∼8 mg/kg)) or an anionic phospholipid (phosphatidylinositol, PI (∼9 mg/kg)) into fasted rabbits. The PI-injection significantly (P < 0.05) increased the negative surface charge of the lipoproteins. The clearance of tritiated-cholesterol from the PI-injected rabbit-plasma was ∼50% greater when compared to controls (P < 0.05). The PI-injection also prevented the formation of cholesteryl ester. To determine how increased lipoprotein PI content may regulate cholesterol clearance by the liver, cell culture studies using a human hepatoma cell-line were undertaken. In vitro enrichment of human plasma or high density lipoproteins with PI caused a ∼2 fold stimulation in cholesterol cellular uptake, relative to controls. PI-enrichment did not affect cellular cholesterol-uptake from low density lipoproteins. These results suggest that lipoprotein PI levels may affect intravascular cholesterol transport.108 p.Chemistry, Biochemistry.Thesis