PRODUCTION OF H2O2 BY ALVEOLAR MACROPHAGES IN EXPERIMENTAL ALLERGIC ALVEOLITIS

Experimental extrinsic allergic alveolitis (EAA) was induced in guinea pigs with Saccharopolyspora rectivirgula. Bronchoalveolar lavages were performed before inducing EAA (day 1, BAL 1), on day 23 (BAL 2), and on day 48 (BAL 3). The number of cells/ml in lavage fluid was increased at BAL 2 (4.79 x 10(6)) and BAL 3 increased simultaneously, neutrophil becoming the predominant cell type over alveolar macrophages (AM). The production of H2O2 by AM was measured at the different phases of EAA. Adherent AM were either non-stimulated or triggered with phorbol myristate acetate (PMA), zymosan, S. rectivirgula opsonized with normal guinea pig serum (SRNS), or S. rectivirgula opsonized with guinea pig anti-S. rectivirgula serum (SRAS). Stimulated AM produced larger quantities of H2O2 than unstimulated cells, PMA being the most potent stimulus. At day 1, AM stimulated with S. rectivirgula and zymosan produced similar quantities of H2O2. After the induction of the disease, AM stimulated with S. rectivirgula produced larger quantities of H2O2 than with zymosan. Production of H2O2 by AM stimulated with S. rectivirgula or PMA, respectively, stayed the same at day 1 and 23, but increased sharply for both stimuli at day 48. There was no difference between H2O2 production by AM triggered with SRNS or with SRAS. This study shows that: 1) H2O2 production is enhanced, especially by the offending agent, in the course of the disease; 2) the enhanced production of H2O2 by AM is preceded by the development of alveolitis; and, 3) the opsonization with specific antibodies does not enhance the avidity of AM for the antigen.