Effects of cholestyramine on lipoprotein levels and metabolism in Syrian hamsters.
Oral administration of cholestyramine to adult male hamsters not only induced a marked decrease in plasma concentrations of cholesterol and LDL but had a similar lowering effect on plasma triacyglycerol and VLDL concentrations. The hypotriglyceridaemic effects of resin administration were not due to an increase in lipoprotein lipase, as post-heparin plasma lipoprotein lipase activities were unchanged, but rather to a 35% decrease in VLDL synthesis. Measurement of the disappearance rate of apolipoprotein B from VLDL after i.v. injection of 125I-labelled hamster or human VLDL into control and cholestyramine-fed recipient animals showed a 2-times lower T1/2 in the drug-treated animals. The fraction of VLDL apolipoprotein B, recovered at any time after injection in the LDL, was equal or higher in cholestyramine-fed animals as compared to controls. These data indicate that the lowering in plasma LDL by cholestyramine in male hamsters is due not only to LDL receptor up-regulation but also to a lower rate of VLDL synthesis. No indications were found for a decreased efficiency of VLDL to LDL conversion in cholestyramine-fed animals.
Groot
P H
PH
SmithKline Beecham Pharmaceuticals, Welwyn, U.K.
Pearce
N J
NJ
Suckling
K E
KE
Eisenberg
S
S
D000818:Animals; D002784:Cholesterol / Q000097:blood; D002792:Cholestyramine Resin / Q000494:pharmacology*; D006224:Cricetinae; D003902:Detergents; D004591:Electrophoresis, Polyacrylamide Gel; D000960:Hypolipidemic Agents / Q000494:pharmacology*; D008071:Lipoprotein Lipase / Q000097:blood; D008074:Lipoproteins / Q000097:blood*; D008077:Lipoproteins, LDL / Q000097:blood; D008079:Lipoproteins, VLDL / Q000097:blood; D008297:Male; D008647:Mesocricetus; D011092:Polyethylene Glycols; D014280:Triglycerides / Q000097:blood
D003902:Detergents; D000960:Hypolipidemic Agents; D008074:Lipoproteins; D008077:Lipoproteins, LDL; D008079:Lipoproteins, VLDL; D014280:Triglycerides; D002792:Cholestyramine Resin; D011092:Polyethylene Glycols; D002784:Cholesterol; D008071:Lipoprotein Lipase; C016811:tyloxapol