title: Inhibition of phorbol ester stimulated superoxide production by 1-oleoyl-2-acetyl-sn-glycerol (OAG); fact or artefact?
abstract: OAG-stimulated superoxide (O2) production by HL-60 granulocytes showed enantiomeric specificity but reached a maximum of only 5% of that produced by either phorbol myristate acetate (PMA) or phorbol dibutyrate (PDBu). At 10-100 microM, OAG displaced specifically-bound [3H]PDBu from intact HL-60 cells by only 25%, suggesting limited cell penetration. OAG (10-100 microM) also inhibited PDBu-stimulated O2 production by 25%; this inhibition was enantiomerically specific. However, at a lower concentration (3 microM), both enantiomers of OAG fully blocked O2 production stimulated by PMA (0.5 microM). This inhibition is probably artefactual, due to the hydrophobic PMA physically associating with OAG in the extracellular fluid.
mesh_terms: D000818:Animals; D001921:Brain / Q000201:enzymology; D002460:Cell Line; D003600:Cytosol / Q000201:enzymology; D004075:Diglycerides / Q000138:chemical synthesis / Q000494:pharmacology*; D005989:Glycerides / Q000494:pharmacology*; D006098:Granulocytes / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D015240:Phorbol 12,13-Dibutyrate; D010703:Phorbol Esters / Q000494:pharmacology*; D011493:Protein Kinase C / Q000378:metabolism; D051381:Rats; D013481:Superoxides / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
chemical_list: D004075:Diglycerides; D005989:Glycerides; D010703:Phorbol Esters; D013481:Superoxides; D015240:Phorbol 12,13-Dibutyrate; C038237:1-oleoyl-2-acetylglycerol; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate