During its life cycle Trypanosoma rangeli crosses the hemolymph of its invertebrate host. In the present study, we demonstrate for the first time the uptake of lipophorin (Lp), the main lipid-transporting particle of insect hemolymph. We observed that living T rangeli parasites uptake lipids from both P-32- and H-3-, or I-125-labeled Lp. However, the parasites do not uptake any other hemolymphatic protein such as P-32-labeled vitellogenin. The presence of a specific receptor to Lp in the parasite surface is suggested based on experiments using I-125-Lp. We also investigated the intracellular fate of lipids using Texas Red-labeled phosphatidylethanolamine-Lp. Parasites were observed under confocal microscope and displayed fluorescent-labeled lipids close to the flagellar pocket and in vesicles at the posterior region. In conclusion, this study raises a novel set of molecular events which takes place during vector-parasite interaction. (C) 2003 Elsevier Inc. All rights reserved.