title: Human peritoneal macrophages synthesize leukotrienes B4 and C4.
abstract: Macrophages were isolated from the dialysis fluid of patients undergoing continuous ambulatory peritoneal dialysis and separated by gradient centrifugation and purification on 50% Percoll. The cells were prelabeled with [14C]arachidonic acid for 1.5 h. The labeled cells were then incubated with calcium ionophore A23187 (1 microM), serum-treated zymosan (200 micrograms/ml), and a lipoxygenase inhibitor, nordihydroguairetic acid (1 X 10(-5) M). The arachidonate metabolites in the medium were separated on Sep-Pak columns, and finally purified by reverse-phase high-pressure liquid chromatography (HPLC). The labeled products co-chromatographed with authentic leukotriene B4 and leukotriene C4 standards. Serum-treated zymosan and A23187 significantly stimulated and nordihydroguairetic acid significantly inhibited leukotriene synthesis. Leukotriene D4 was not detected, which suggests that these cells contain low gamma-glutamyltranspeptidase or high dipeptidase activity. These results establish, for the first time, that human peritoneal macrophages synthesize the lipoxygenase products, leukotriene B4 and leukotriene C4.
mesh_terms: D002499:Centrifugation, Density Gradient; D055598:Chemical Phenomena; D002621:Chemistry; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D066298:In Vitro Techniques; D007975:Leukotriene B4 / Q000096:biosynthesis* / Q000302:isolation & purification; D008264:Macrophages / Q000378:metabolism*; D010531:Peritoneal Dialysis, Continuous Ambulatory; D013189:SRS-A / Q000096:biosynthesis* / Q000302:isolation & purification
chemical_list: D013189:SRS-A; D007975:Leukotriene B4