Responsiveness of guinea pig alveolar cells

Secretion of thromboxane B2 and prostaglandin E2 by guinea-pig lung cells isolated by centrifugal elutriation and by macrophages obtained by bronchoalveolar lavage

Guinea-pig lung cells were partially purified by an elutriation technique after enzymatic digestion of the lung. Eight fractions were obtained and the cell content of each fraction was analysed by staining and by electron microscopy. After stimulation with selected agonists, the secretion of eicosanoids has been measured in the supernatants of each elutriation fraction and in the supernatants of alveolar macrophages obtained by bronchoalveolar lavage. The cell response was characterised by a marked secretion of thromboxane B2 (TXB2) and prostaglandin E2 (PGE2) from the alveolar macrophages and a more discrete secretion of TXB2 from the cells of the elutriated fractions. The secretion of TXB2 varied in the cell fractions as a function of the cellular composition and the agonist used. Platelet activating factor (PAF) and ethoxy PAF, phorbol myristate acetate (PMA) and ionophore A-23187 stimulated most cell types although PMA produced a more important stimulation of the fractions containing pneumocytes and eosinophils, and ionophore A-23187 appeared to stimulate Foa-Kurloff cells. The chemotactic peptide fMLP stimulated markedly the fractions containing the inflammatory cells (mast cells, macrophages, neutrophils) and endothelial cells. Pretreatment of the cells with cytochalasin B potentiated the release of TXB2 and PGE2 by macrophages following stimulation with PAF, leukotriene D4 (LTD4) and formyl-methionyl-leucyl-phenylalanine (fMLP) but not by mixed lung cells or by elutriation fractions. In conclusion, the recovery of a large number of partially purified lung cell types was made possible by mild protease digestion and elutriation.(ABSTRACT TRUNCATED AT 250 WORDS)