title: In vitro lipid transfer between lipoproteins and midgut-diverticula in the spider Polybetes pythagoricus.
abstract: It has been already reported that most hemolymphatic lipids in the spider Polybetes pythagoricus are transported by HDL1 and VHDL lipoproteins. We studied in vitro the lipid transfer among midgut-diverticula (M-diverticula), and either hemolymph or purified lipoproteins as well as between hemolymphatic lipoproteins. M-diverticula and hemolymph were labeled by in vivo (14)C-palmitic acid injection. In vitro incubations were performed between M-diverticula and either hemolymph or isolated lipoproteins. Hemolymph lipid uptake was associated to HDL1 (67%) and VHDL (32%). Release from hemolymph towards M-diverticula showed the opposite trend, VHDL 75% and HDL1 45%. Isolated lipoproteins showed a similar behavior to that observed with whole hemolymph. Lipid transfer between lipoproteins showed that HDL1 transfer more (14)C-lipids to VHDL than vice versa. Only 38% FFA and 18% TAG were transferred from M-diverticula to lipoproteins, while on the contrary 75% and 73% of these lipids, respectively, were taken up from hemolymph. A similar trend was observed regarding lipoprotein phospholipids. This study supports the hypothesis that HDL1 and hemocyanin-containing VHDL are involved in the uptake and release of FFA, phospholipids and triacylglycerols in the spider P. pythagoricus. The data support a directional flow of lipids from HDL1 and VHDL suggesting a mode of lipid transport between lipoproteins and M-diverticula.
authors: Instituto de Investigaciones Bioquímicas de La Plata, CONICET-UNLP, La Plata, Argentina.
authors: Aldana
authors: A
authors: Laino
authors: Mónica L
authors: ML
authors: Cunningham
authors: Horacio
authors: H
authors: Heras
authors: Fernando
authors: F
authors: Garcia
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000502:physiology*; D004064:Digestive System / Q000737:chemistry / Q000378:metabolism*; D006433:Hemocyanins / Q000737:chemistry / Q000378:metabolism; D006458:Hemolymph / Q000737:chemistry / Q000378:metabolism*; D050356:Lipid Metabolism / Q000502:physiology*; D008055:Lipids / Q000737:chemistry; D008074:Lipoproteins / Q000737:chemistry / Q000378:metabolism*; D008075:Lipoproteins, HDL / Q000737:chemistry / Q000378:metabolism; D013112:Spiders / Q000737:chemistry / Q000378:metabolism*
chemical_list: D008055:Lipids; D008074:Lipoproteins; D008075:Lipoproteins, HDL; C026277:very high density lipoproteins; D006433:Hemocyanins