Lipoxygenase products and the polymorphonuclear leucocyte.

Polymorphonuclear leucocytes (PMNs), when exposed to the calcium ionophore A23178, release into the supernatant a substance that causes the aggregation and chemokinesis of fresh PMN suspensions. Release of these activities is inhibited by preincubation with drugs known to inhibit lipoxygenase pathways of arachidonic acid metabolism but is unaffected by cyclooxygenase inhibitors. The substance responsible for these activities has been identified as leukotriene B and this compound has been shown to be a potent chemokinetic and aggregatory agent for PMNs over the range 10 pg to 5 ng ml-1.