Fig. 2.

Endogenous levels of EEQ-EA and EDP-EA regioisomers in rat tissues and their production in BV-2 microglial cells. (A) Authentic standards were used for the development of a LC-MS/MS method in the separation and quantitation of EEQ-EA, EDP-EA, AEA, EPEA, and DHEA lipid mediators using MS/MS fragments and retention times unique to each lipid class. (B and C) Lipid metabolites were extracted and analyzed from pooled Sprague–Dawley rat brain (n = 3) (B) and peripheral organs (C). (D and E) The capacity of LPS-activated BV-2 microglia cells to convert EPEA directly to EEQ-EA regioisomers (D) and DHEA into EDP-EA regioisomers (E) was examined in the absence and presence of the CYP inhibitor ketoconazole (0.5 µM).