Possible Interaction: Arachidonic Acid and Phenylephrine

“In aortic strips with an intact endothelium that were treated with phenylephrine, arachidonic acid (10 &mgr;mol/L) increased the membrane potential from −28.7±1.3 to −37.8±3.0 mV (P <0.01).”

“ AA and phenylephrine treatment led to an increase of H2O2 in a dose-dependent manner.”

“In intact smooth muscle, PE increased both AA and DAG levels significantly, to 210 and 145% of baseline values, respectively.”

“The contractile response to phenylephrine was amplified by previous application of subthreshold concentrations of 5-hydroxytryptamine, ouabain, B-HT 920, Bay K 8644, phorbol-12-myristate-13-acetate and arachidonic acid.”

“These data were taken as an evidence that the … relaxing factor(s) but not cyclooxygenase products of arachidonic acid from the endothelium … contractile effect of phenylephrine and the enhanced response to this alpha-adrenoceptor agonist in the second … production or release of these endogenously occurring endothelium-originated substance(s).”

“Our findings also suggest that the action of phenylephrine to promote the liberation of arachidonic acid utilizes both of these reactions.”

“ Arachidonic acid dilated phenylephrine-contracted rings in a concentration-dependent manner.”

“Under these conditions, relaxation in response to 100 microM AA was 32(+/- 3)% of the tension stimulated by 10(-7) M phenylephrine.”

“was partially inhibited by baclofen, atropine, d-tubocurarine, alcuronium, phenylephrine and PGE2, while it was enhanced by arachidonic acid and indomethacin.”

“In contrast, AA elicited concentration-related relaxation in canine IPA partially contracted by phenylephrine.”