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Transfer of phospholipids from fat body to lipophorin in Rhodnius prolixus
Author(s) -
Atella Geórgia Corrêa,
Gondim Katia Calp,
Masuda Hatisaburo
Publication year - 1992
Publication title -
archives of insect biochemistry and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.576
H-Index - 66
eISSN - 1520-6327
pISSN - 0739-4462
DOI - 10.1002/arch.940190206
Subject(s) - rhodnius prolixus , biology , phospholipid , phosphatidylethanolamine , phosphatidylcholine , biochemistry , fat body , adipokinetic hormone , sphingomyelin , phosphatidylinositol , phosphatidylserine , incubation , chromatography , cholesterol , insect , chemistry , ecology , kinase , membrane , gene
32 P‐Labeled fat bodies ( 32 P‐fat bodies) of Rhodnius prolixus females were incubated in the presence of nonradioactive purified lipophorin and the release of radioactivity to the medium was analysed to answer the question of whether lipophorin is a reusable shuttle for phospholipids. The radioactivity found in the medium was associated with lipophorin phospholipids. When the 32 P‐fat bodies were incubated in the absence of lipophorin, only a small amount of radioactivity was released and it was not associated with lipophorin, indicating that there was no release of pre‐labeled 32 P‐lipophorin by the tissue. Analysis of the 32 P‐phospholipids transferred from fat bodies to the lipophorin particles by thin‐layer chromatography revealed a predominance of phosphatidylethanolamine and phosphatidylcholine, with minor amounts of phosphatidylserine, phosphatidylinositol, and sphingomyelin. The transfer of phospholipids to lipophorin was linear with time up to 45 min and the process was inhibited at low temperature and by the metabolic inhibitors azide and fluoride. The transfer of phospholipids from the fat bodies to lipophorin was saturable with respect to the concentration of lipophorin, which was half‐maximal at about 8 mg/ml. A directional movement of phospholipids from the fat body to lipophorin was observed. The net gain of phospholipids in 2 h of incubation with fat body was 8.54 nmol per insect, which corresponds to 6.69% of increase in the lipophorin phospholipid content. The rate of 32 P‐phospholipid transfer from fat body to lipophorin particles varied during the days after a blood meal increasing up to day 10 and then decreasing in parallel with the process of oogenesis.