Fatty acid incorporation by Rhodnius prolixus midgut

[C-14]Oleic acid injected into the hemocoel of Rhodnius prolixus females wa s shown to rapidly associate with lipophorin particles. Half of the lipopho rin-associated [C-14]oleic acid was transferred in about 5 min to different organs, but the midgut was the main organ to take it up on day 10 after a blood meal. The rate of [C-14]oleic acid incorporation by the midgut was hi gh up to 15 min after injection and then declined. The [C-14]oleic acid inc orporated by the midgut was found in phospholipids (58.6%) and neutral lipi ds (37.4%), The midgut capacity to incorporate [C-14]oleic acid varied on d ifferent days after a meal: it increased up to day 10 and then decreased. T he fate of the [C-14]lipids synthesized by the midgut was followed and it w as observed that 10 days after feeding diacylglycerol was the main lipid re leased to hemolymph and that most of phospholipids and triacylglycerols rem ained associated with the midgut. The metabolism of free fatty acids in Rho dnius prolixus females is discussed in the context of major biological even ts that follow a blood meal such as digestion and oogenesis. Arch. Insect B iochem. Physiol. 43:99-107, 2000. (C) 2000 Wiley-Liss, Inc.