Releasability of human basophils and mast cells is an important parameter in allergic disorders. We compared IgE- and non-IgE-mediated releasability of human peripheral blood basophils with that of mast cells obtained from lung parenchyma (isolated by mechanical or enzymatic dissociation) and from bronchoalveolar lavage of normal and asthmatic donors. In a first study, the response to anti-IgE, Staph A, Con A, f-met peptide, and Ca2+ ionophore A23187 of basophils obtained from 52 donors was compared with that of mast cells isolated enzymatically (PMCE) or mechanically (PMCM) from lung parenchyma obtained during surgery. The histamine content of basophils (1.1 +/- 0.1 pg/cell) was significantly lower than that of PMCE (4.1 +/- 0.3 pg/cell; p less than 0.001) and PMCM (3.7 +/- 0.3; p less than 0.001). The maximal percent anti-IgE-induced histamine secretion in basophils (41.3 +/- 3.6) was higher than in PMCE (17.5 +/- 1.8) and in PMCM (13.8 +/- 1.5). Similarly, the response to Staph A and Con A was higher in basophils (29 +/- 3.9 and 31.6 +/- 4.9, respectively) than in PMCE (3.5 +/- 0.6 and 3.3 +/- 0.8, respectively) and PMCM (5.1 +/- 1.3 and 8.8 +/- 2.2, respectively). A positive correlation between the maximal percent of histamine release induced by anti-IgE and Staph A was found in basophils (rs = 0.61; p less than 0.001), whereas there was a negative correlation between the reactivity of PMCE (rs = 0.67; p less than 0.001) and PMCM (rs = -0.40; p less than 0.001) to anti-IgE and their reactivity to Staph A.(ABSTRACT TRUNCATED AT 250 WORDS)