Synthesis of arachidonic acid metabolites by Syrian hamster platelets and peritoneal cells

Abstract

In this study, the metabolism of arachidonic acid by hamster platelets and peritoneal macrophages was assessed. Peritoneal macrophages stimulated in vitro with the calcium ionophore A23187 or stimulated in vivo by intraperitoneal injections of opsonized zymosan produced prostaglandin E2, thromboxane B2 (TxB2) and 6-keto-prostaglandin F1 alpha, as determined by radioimmunoassays. Leukotriene B4 (LTB4), and 11- and 15-hydroxyeicosatetraenoic acids (HETE), which were identified by reverse-phase high-performance liquid chromatography coupled with diode array detection, were produced by peritoneal cells stimulated in vitro with A23187 but were not found in the peritoneal exudate following in vivo stimulation with opsonized zymosan. Synthesis of 11- and 15-HETE, but not LTB4, was inhibited by 1 microM indomethacin but not by 10 microM nordihydroguaiaretic acid, which did inhibit LTB4 synthesis. Washed hamster platelets were prepared and shown to synthesize TxB2, 12-HETE and 12-hydroxyheptadecatrienoic acid following stimulation with thrombin. This paper is the first to report on eicosanoid metabolism in tissues related to atherosclerosis, thrombosis and inflammation in hamsters.