Possible Interaction: Arachidonic Acid and Hydrogen Peroxide

“Although hydroperoxides and isoprostanes are major autoxidation products of AA , EETs are also formed from the largely overlooked peroxyl radical addition mechanism.”

“ Hydrogen peroxide (H(2)O(2)) stimulates the release of arachidonic acid from cells, but the signaling mechanism(s) involved remains to be elucidated.”

“ Arachidonic and α-linolenic acids treatment enhanced LPS-stimulated H2O2 production by PBMCs, while palmitic, oleic, γ-linolenic, and docosahexaenoic acids did not exert significant effects.”

“Indeed, we found that high concentrations of hydroperoxide activator (e.g. 65 μm) overcame a prolonged lag phase (>1 h) and unveiled a dioxygenase activity with arachidonic acid ; the main products were the 5-, 9-, and 7-hydroperoxyeicosatetraenoic acids (HPETEs).”

“ H2O2 inhibited dilation to arachidonic acid but not to 11,12-EET.”

“ AA produced toxic effects, especially in the 2E1 cells, and caused a remarkable increase in hydrogen peroxide production and lipid peroxidation compared to the Neo and HepG2 cells.”

“Adding 100 microM H2O2 prior to arachidonic acid decreased PGI2 synthesis more than 80%.”

“ H2O2 (0.5 to 5 mumol/L) alone did not influence platelet function, but when it was combined with subthreshold concentrations of arachidonic acid or collagen, it induced platelet aggregation and serotonin release in a dose-dependent fashion.”

“ H2O2 alone did not affect intraplatelet Ca++ influx or mobilization but, combined with subthreshold concentrations of arachidonic acid , it increased Ca++ mobilization.”

“This study suggests that H2O2 triggers the activation of platelets exposed to STC of collagen and arachidonic acid , via the cyclooxygenase pathway.”

“While H2O2 alone did not affect platelet aggregation, it amplified platelet aggregation response in samples stimulated with STC of arachidonic acid and collagen but not in samples stimulated with STC of ADP.”

“Addition of hydrogen peroxide , 15-hydroperoxyeicosatetraenoic acid, or inhibition of the lipoxygenase metabolic pathway by 4,7,10,13-eicosatetraynoic acid also induced a hypersensitive aggregation response to AA.”