Platelets, prostaglandins and inflammation.

In exudates of implanted sponges in rats, made thrombocytopenic by the administration of anti-platelet serum, there are significant reductions in the platelet and leucocyte counts and of the content of prostaglandin-like activity. It is concluded that platelets migrate into the developing sponge exudates, are the source of the prostaglandins and interact with complement to cause leucocyte migration. In normal animals the administration of indomethacin and sodium salicylate cause similar effects to thrombocytopenia whereas the injection of human plasma fraction affects only the leucocyte migration. One of the sites of the anti-inflammatory action of conventional non-steroidal drugs may be concerned with the migration of platelets into inflammatory lesions.