title: Transfer of arachidonic acid from lymphocytes to macrophages.
abstract: The incorporation and oxidation of arachidonic acid (AA) by rat lymphocytes (LY), the transfer of AA from LY to rat macrophages (Mphi) in co-culture, and the subsequent functional impact on Mphi phagocytosis were investigated. The rate of incorporation of [1-14C]AA by untreated-LY and TG (thioglycolate treated)-LY (TG-LY) was 158 +/- 8 nmol/10(10) LY per h for both untreated-LY and TG-LY. The oxidation of AA was 3.4-fold higher in TG-LY as compared with untreated cells. LY from TG-injected rats had a 2.5-fold increase in the oxidation of palmitic (PA), oleic (OA), and linoleic (LA) acids. After 6 h of incubation, [14C] from AA was distributed mainly into phospholipids. The rate of incorporation into total lipids was 1071 nmol/10(10) cells in untreated-LY and 636 nmol/10(10) cells in TG-LY. [14C]AA was transferred from LY to co-cultured Mphi in substantial amounts (8.7 nmol for untreated and 15 nmol per 10(10) for TG cells). Exogenously added AA, PA, OA, and LA caused a significant reduction of phagocytosis by resident cells. Mphi co-cultured with AA-preloaded LY showed a significant reduction of the phagocytic capacity (about 40% at 35 microM). LY preloaded with PA, LA, and OA also induced a reduction in phagocytic capacity of co-cultured Mphi. TG treatment abolished the AA-induced inhibition of phagocytosis in Mphi co-cultured with TG-LY. Therefore, the transfer of AA between leukocytes is a modulated process and may play an important role in controlling inflammatory and immune response.
authors.affiliation: Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil. carmem@fisio.icb.usp.br
authors.forename: C M
authors.initials: CM
authors.lastname: Peres
authors.forename: S C
authors.initials: SC
authors.lastname: Sampaio
authors.forename: Y
authors.initials: Y
authors.lastname: Cury
authors.forename: P
authors.initials: P
authors.lastname: Newsholme
authors.forename: R
authors.initials: R
authors.lastname: Curi
mesh_terms: D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D002247:Carbon Isotopes; D002478:Cells, Cultured; D002855:Chromatography, Thin Layer; D018920:Coculture Techniques; D050356:Lipid Metabolism; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D008264:Macrophages / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D013864:Thioglycolates / Q000494:pharmacology
chemical_list: D002247:Carbon Isotopes; D013864:Thioglycolates; D016718:Arachidonic Acid