Oxygen metabolism and eicosanoid formation of alveolar macrophages of Haemophilus influenzae-treated guinea pigs

The aim of the present study was to directly measure the production of oxygen metabolites and eicosanoid mediators by AMs during incubation with sera. In addition, we investigated if there are differences in action of AMs isolated from H. influenzae-treated and control guinea pigs. In our studies no differences in oxygen metabolism between AMs from H. influenzae-treated and control animals were observed. In the studies of Engels et al. sera from H. influenzae-treated and control animals were used to stimulate AMs and differences between these two sera in their action on AMs were observed. As measured by the release of hydrogen peroxide, no stimulation of oxygen metabolism by sera could be observed. Stimulation with phorbol myristate acetate or zymosan, however, indicated that guinea pig AMs can release hydrogen peroxide. It can not be excluded that the methods used by us to measure oxygen species are too insensitive to detect the oxygen metabolites that caused the changes in β-adrenoceptor function. In the model of Engels et al., AMS are attached to the isolated tracheal spirals resulting in a close proximity of the AMs to the tissues. Thus, short-lived mediators from AMs could be able to influence the tracheal tissue.