Stimulus-related difference in the formation of leukotrienes and PGD2 after immunological and non-immunological challenge of human lung parenchyma 'in vitro'

The stimulation of human lung parenchymal fragments with A-23187 induces formation of leukotrienes as well as of PGD 2 : LTE 4 is the compound found in larger amount and independently of the intensity of the stimulus the % of metabolized precursor which is converted to leukotrienes or PGD 2 is remarkably similar. However, under conditions of IgE-AntilgE challenge the predominant conversion of arachidonic acid occurs to PGD 2 , LTB 4 is almost negligible and LTD 4 and E 4 together represent less Ln 30% of the oxidative products of arachidonic acid. Whether PGD 2 and leukotrienes derive from the same or different subset of cells is unresolved.