VARIATIONS OF LIPID AND APOLIPOPROTEIN CONTENT IN LIPOPROTEINS DURINGFASTING IN EUROPEAN SEA BASS (DICENTRARCHUS-LABRAX L.)

Lipoproteins are involved in transport of exogenous and endogenous lip ids. For this reason, the lipoprotein pattern undergoes drastic variat ion during fasting. In D. labrax, observed variations concern the rela tive content of the five lipoproteins and their composition, both in l ipid and apolipoprotein content. These data indicate the presence of a cascade mechanism of maturation involving very-low-density lipoprotei n, (VLDL), low-density lipoprotein (LDL)-1 and LDL-2. In addition, a m etabolic 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 patter n and are composed of almost 80% triglycerides. From the evolutionary point of view, HDL represent the most conserved lipoproteins and are i nvolved in transportation of endogenous lipids, mobilized from accumul ation tissues. Their apolipoprotein pattern is dominated by two apolip oproteins, apo Al (26,000 Da) and apo A2 (12,000 Da). (C) 1997 Elsevie r Science Inc.