Regulation of Arachidonic Acid Release by Some Agonists on Suspended and Attached Neutrophils

[H] Arachidonic acid is released after stimulation of suspended and attached neutrophils. The arachidonic acid release in attached cells is more than in suspended cells. This release is rapid with the increase of incubation time and dose depended. The Fmet-Leu-Phe (FMLP) potentiates [H] arachidonic acid release in attached cells pretreated with LPS and serum. [H] arachidonic acid release was less in suspended cells in comparison to attached cells where the addition of low concentration of LPS in presence of serum or platelet activating factor (PAF) to suspended cells produce increase in arachidonic acid release, where lps in combination with PAF produce a large and significant increase in arachidonic acid release. The potentiative effect of LPS is mediated via CD14 receptors. The monoclonal antibodies against CD14 had no effect on arachidonic acid release in PAF treated cells where it inhibited greatly the potentiation by LPS or LPS-serum complex with PAF.