Aspects of cholesterol metabolism in normal and hypercholesterolemic Syrian hamsters. Influence of fenofibrate.

This study reports the short-term effects of fenofibrate in golden Syrian hamsters receiving a standard or cholesterol enriched (0.5%) diet. In chow fed control animals, the plasma cholesterol (132 mg/dl) was transported essentially by LDL (27%) and HDL (56%). Conversely, the bulk of triglycerides (114 mg/dl) circulated in VLDL (54%). One week of hypercholesterolemic diet increased plasma cholesterol (+80%) and it is reflected in a 3.3-fold increase in VLDL, 2.8-fold in IDL, 1.6-fold in LDL and 1.5-fold in HDL, accompanied by a rise in cholesterol hepatic level by a factor of 4.5. 15 days of treatment with fenofibrate (300 mg/kg/d) produced a decrease in free plasma cholesterol (-21%) without modification in total cholesterol level in chow fed animals. In liver, cholesterol was reduced by 27% and triglycerides were raised by 58%. In animals receiving the hypercholesterolemic diet, fenofibrate increased hepatic and plasmatic triglyceride levels (55 and 54%, respectively), although it slightly reduced plasma cholesterol levels and more markedly the hepatic cholesterol content (-55%). In chow fed animals, cholesterol biosynthesis was decreased by fenofibrate treatment by 40%. The effects of fenofibrate on triglyceride levels are in contrast to experiences in other animal species, including man, and indicate a hypersecretion of chylomicrons and/or a hypersecretion of VLDL, although the explanations are not yet obvious. The results concerning cholesterol metabolism indicate similarities between man and hamster.