LIPID FLUIDITY OF TRIACYLGLYCEROL-RICH LIPOPROTEINS ISOLATED FROM COPPER-DEFICIENT RATS

Triacylglycerol-rich lipoproteins (TGRLP) were isolated from Cu-defici ent and control rats, TGRLP from Cu-deficient rats appeared more fluid than those from controls as sensed by the fluorescence anisotropy of 1,6-diphenyl-1-3,5-hexatriene (DPH), This high fluidity was related to a low cholesterol: phospholipid ratio and high triacylglycerol conten t in these lipoproteins. TGRLP from Cu-deficient rats were more suscep tible to in vitro peroxidation than lipoproteins from control rats as shown by the rate of diene conjugation. The damage induced by the pero xidation resulted in a more ordered state of the lipid fraction especi ally in Lipoproteins from Cu-deficient rats, Thus, after in vitro pero xidation, TGRLP from Cu-deficient rats were more rigid than those from controls, These results suggest that Cu deficiency induces modificati ons in physicochemical properties of TGRLP which could affect their me tabolism.