Effect of simvastatin on receptor-dependent low density lipoprotein catabolism in normocholesterolemic human volunteers.
Simvastatin, an inhibitor of HMG-CoA reductase was given to 7 normolipidemic healthy volunteers for 1 month at a dose of 20 mg/day. Measurements of turnover of low density lipoprotein apolipoprotein B (LDL-apo B) were determined before and after drug treatment using intravenous injection of 125I-labeled LDL and 131I-labeled cyclohexanedione-treated LDL to quantify the receptor pathway. In addition to a 13% increase in HDL cholesterol and apolipoprotein A-I concentrations, plasma cholesterol was reduced by 20%, LDL-cholesterol by 32%, and apolipoprotein B by 23%. Assuming a heterogeneous pool of LDL, the new model presented in the companion paper was built to calculate the contribution of the receptor-dependent and the receptor-independent pathways and the corresponding fractional catabolic rates. Simvastatin did not modify constantly the synthetic rate of LDL-apo B but increased the fractional catabolic rate of the receptor-dependent pathway and the contribution of this pathway in the catabolism. The fall in LDL plasma levels observed in normocholesterolemic subjects can be then entirely explained by an enhanced fractional removal of LDL from the circulation by the receptor route.
Malmendier
C L
CL
Fondation de Recherche sur l'Athérosclérose and Research Unit on Atherosclerosis, Université Libre de Bruxelles, Belgium.
Lontie
J F
JF
Delcroix
C
C
Magot
T
T
D000328:Adult; D000924:Anticholesteremic Agents / Q000494:pharmacology*; D001055:Apolipoproteins B / Q000378:metabolism*; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008148:Lovastatin / Q000031:analogs & derivatives* / Q000494:pharmacology; D008297:Male; D008954:Models, Biological; D011973:Receptors, LDL / Q000187:drug effects* / Q000378:metabolism; D019821:Simvastatin
D000924:Anticholesteremic Agents; D001055:Apolipoproteins B; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D008077:Lipoproteins, LDL; D011973:Receptors, LDL; D008148:Lovastatin; D019821:Simvastatin