Changes of lipids and lipoproteins in cholesterol free-high fructose diet-fed rats and the effects of clinofibrate

The present study was performed to determine the serum lipid and lipoprotein changes in cholesterol free-high fructose diet (HFD)-fed rats and to examine the effects of clinofibrate (CF) on these changes. HFD feeding for 2 weeks increased the high density lipoprotein (HDL1) subfraction and decreased the low density lipoprotein subfraction. The contents of total cholesterol (TC), triglyceride (TG) and phospholipid (PL) in the serum increased by HFD feeding. CF inhibited the increases in HDL1 and lipid content. The continuance of HFD-induced hyperlipidemia was investigated in rats fed a normal diet after HFD feeding for 4 weeks. The HFD-induced increases of TC, PL and HDL1 continued for 5 days. TG was also increased by HFD feeding, but the elevated level was not maintained after feeding of the normal diet was initiated. The administration of CF for 3 or 5 days to the rats that had been switched to the normal diet inhibited the increases in lipids and HDL1. The increase of cholesterol synthetic activity continued for 3 days after the rats were switched to the normal diet but CF increased to a higher level than that of the HFD group. The main mechanism of the hypolipidemic effect of CF on HFD-induced hyperlipidemia is considered to be the increase of lipid excretion and HDL1 metabolism.