Hyperresponsiveness to dietary cholesterol in inbred rabbits is not associated with enhanced reduction in binding of beta-VLDL to liver membranes.
In two inbred strains of rabbits with high or low response of serum cholesterol to dietary cholesterol, binding of rabbit beta-VLDL to hepatic membrane preparations was determined. The objective was to test the hypothesis that after cholesterol feeding, hyperresponders show a more dramatic reduction in hepatic apolipoprotein (apo) B/E receptors, which may explain the development of the high degree of cholesterolemia in these animals. The number of hepatic high affinity receptors for beta-VLDL in hyperresponders fed a diet without added cholesterol was, on average, 20% lower than that in hyporesponders. After the addition of increasing amounts of cholesterol to the diet, liver cholesterol concentrations were elevated to a greater extent in hyper- than in hyporesponsive rabbits. Liver free cholesterol concentrations were negatively associated with maximal binding of beta-VLDL to liver membranes. With increasing liver free cholesterol concentrations, maximal binding was less effectively depressed in hyper- than hyporesponders. We conclude that in the inbred strains of rabbits, hyperresponsiveness to dietary cholesterol is not caused by enhanced depression of hepatic apo B/E receptors.
Meijer
G W
GW
Department of Laboratory Animal Science, University of Utrecht, The Netherlands.
Beynen
A C
AC
Lovati
M R
MR
Manzoni
C
C
Van Zutphen
L F
LF
Sirtori
C R
CR
D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002791:Cholesterol, Dietary / Q000097:blood / Q000378:metabolism / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D008079:Lipoproteins, VLDL / Q000378:metabolism*; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D011817:Rabbits
D002791:Cholesterol, Dietary; D008079:Lipoproteins, VLDL