Production of singlet oxygen by eosinophils activated in vitro by C5a and leukotriene B4

Abstract

Using the trans-methoxyvinylpyrene analogues of benzo[ a]pyrene-7,8-dihydrodiol (MVP) as a singlet oxygen ( 1O 2) chemiluminescence probe, we have demonstrated that guinea pig eosinophils release 1O 2 when activated with the physiological agonists C5a and leukotriene B 4. This release, which occurs at agonist concentrations as low as 10 −7 M, occurs more rapidly than activation with phorbol ester (10 −6 M), is similar in level, but is more transitory. In addition, the release of 1O 2 occurs in the absence of added bromide ions and represents, we propose, an important feature of eosinophil-mediated inflammatory damage.