PEPTIDOLEUKOTRIENE (PLT) RELEASE FROM GUINEA-PIG LUNG MAST-CELLS

Guinea pig lung mast cells can be isolated and purified to high purity . This has given us the opportunity to study in greater detail mediato r release from these cells. Both immunologic (ovalbumin sensitized) an d nonimmunologic (calcium ionophore, CaI) stimuli caused a dose-depend ent release of histamine and pLT from monodispersed lung cells and hig hly purified lung mast cells. Examination of the time release curve fo r pLT revealed a 5-min lag in the release of this mediator and a peak release at 60 min after challenge with antigen. Verification of pLT re lease was obtained by use of the 5-lipoxygenase inhibitor A64077 (Zile uton). Pretreatment of lung mast cells with the 5-lipoxygenase inhibit or prevented release of pLT by either antigen or CaI but had no apprec iable effect on histamine release (HR). The pulmonary mast cell appear s to be an important contributor to pLT release in the guinea pig lung .