Variations of lipid and apolipoprotein content in lipoproteins during fasting in European sea bass (Dicentrarchus labrax L.)

Abstract

Lipoproteins are involved in transport of exogenous and endogenous lipids. For this reason, the lipoprotein pattern undergoes drastic variation during fasting. In D. labrax, observed variations concern, the relative content of the five lipoproteins and their composition, both in lipid and apolipoprotein content. These data indicate the presence of a cascade mechanism of maturation involving very-low-density lipoprotein, (VLDL), low-density lipoprotein (LDL)-1 and LDL-2. In addition, a metabolic correlation involves VLDL and high-density lipoprotein (HDL). VLDL are functionally comparable with mammalian chylomicrons; in fact, they disappear rapidly after feeding from the chromatographic pattern and are composed of almost 80% triglycerides. From the evolutionary point of view, HDL represent the most conserved lipoproteins and are involved in transportation of endogenous lipids, mobilized from accumulation tissues. Their apolipoprotein pattern is dominated by two apolipoproteins, apo A1 (26,000 Da) and apo A2 (12,000 Da).