Lipid dynamics of arachnid lipoproteins

LAINO ALDANA; F. GARCIA; H.HERAS; CUNNINGHAM M.

Congreso; Reunión Anual de la Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular.; 2010

It has been already reported that hemolymphatic lipids in the spider P. pythagoricus aretransported by HDL1 and VHDL lipoproteins. In the present work we studied in vitro the lipid transfer among intestinal diverticula (ID), principal organ involved in lipid biosynthesis, and either hemolymph (HL) or purified lipoproteins as well as between HL lipoproteins. ID and HL were labeled in vivo with 14C-palmitic acid. In vitro incubations were between ID and HL, as well as between isolated lipoproteins and ID were performed, being lipid transfer quantified by radio-TLC. Lipoproteins (VHDL and in a minor extent by HDL1) released 76% of its lipids to ID. Isolated lipoproteins showed the same behavior to that observed with whole hemolymph. Lipid uptake in hemolymph was greater in HDL1 (67%), though it was similar when the isolated lipoproteins (50% each) were assayed. Lipid uptake and release in these systems were found to be constant within a wide range of starting lipid label. Intestinal diverticula were found to retain free fatty acids and triacylglicerides as only 28% of the label were transferred to lipoproteins while 76% was taken up from HL. A similar trend was observed regarding lipoprotein PL.