title: Perimicrovillar membrane assembly: the fate of phospholipids synthesised by the midgut of Rhodnius prolixus.
abstract: In this study, we describe the fate of fatty acids that are incorporated from the lumen by the posterior midgut epithelium of Rhodnius prolixus and the biosynthesis of lipids. We also demonstrate that neutral lipids (NL) are transferred to the haemolymphatic lipophorin (Lp) and that phospholipids remain in the tissue in which they are organised into perimicrovillar membranes (PMMs). 3H-palmitic acid added at the luminal side of isolated midguts of R. prolixus females was readily absorbed and was used to synthesise phospholipids (80%) and NL (20%). The highest incorporation of 3H-palmitic acid was on the first day after a blood meal. The amounts of diacylglycerol (DG) and triacylglycerol synthesised by the tissue decreased in the presence of Lp in the incubation medium. The metabolic fates of 3H-lipids synthesised by the posterior midgut were followed and it was observed that DG was the major lipid released to Lp particles. However, the majority of phospholipids were not transferred to Lp, but remained in the tissue. The phospholipids that were synthesised and accumulated in the posterior midgut were found to be associated with Rhodnius luminal contents as structural components of PMMs.
authors.affiliation: Instituto de Bioquímica Médica, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brasil.
authors.forename: Paula Rêgo
authors.initials: PR
authors.lastname: Bittencourt-Cunha
authors.forename: Livia
authors.initials: L
authors.lastname: Silva-Cardoso
authors.forename: Giselle Almeida de
authors.initials: GA
authors.lastname: Oliveira
authors.forename: José Roberto da
authors.initials: JR
authors.lastname: Silva
authors.forename: Alan Barbosa da
authors.initials: AB
authors.lastname: Silveira
authors.forename: George Eduardo Gabriel
authors.initials: GE
authors.lastname: Kluck
authors.forename: Michele
authors.initials: M
authors.lastname: Souza-Lima
authors.forename: Katia Calp
authors.initials: KC
authors.lastname: Gondim
authors.forename: Marilvia
authors.initials: M
authors.lastname: Dansa-Petretsky
authors.forename: Carlos Peres
authors.initials: CP
authors.lastname: Silva
authors.forename: Hatisaburo
authors.initials: H
authors.lastname: Masuda
authors.forename: Mario Alberto Cardoso da
authors.initials: MA
authors.lastname: Silva Neto
authors.forename: Georgia Correa
authors.initials: GC
authors.lastname: Atella
mesh_terms: D000818:Animals; D004064:Digestive System / Q000378:metabolism*; D005260:Female; D050356:Lipid Metabolism / Q000502:physiology*; D008563:Membrane Lipids / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism*; D012239:Rhodnius / Q000378:metabolism* / Q000502:physiology
chemical_list: D008563:Membrane Lipids; D010743:Phospholipids