Secretion of interleukin 1/leucocytic pyrogen from endotoxin-stimulated human alveolar macrophages is unaffected by indomethacin

Human alveolar macrophages obtained from 7 normal volunteers and 7 patients with lung disease were stimulated with endotoxin (lipolysaccharide) to induce interleukin 1/leucocytic pyrogen (IL1/LP) secretion. Using the thymocyte assay we quantitated IL1/LP activity in macrophage supernatants obtained after 24h. 10ωg/ml lipopolysaccaharide stimulated alveolar macrophages to secrete significantly more IL1/LP activity than did 1 ωg/ml. Apart from one patient with sarcoidosis, the presence of indomethacin did not significantly inhibit the quantity of IL1/LP secreted in response to LPS. We also demonstrated that the presence of indomethacin did not affect the response of thymocytes to IL1/LP. We conclude that the secretion of IL1/LP by human alveolar macrophages in response to endotoxin is not significantly reduced by the cyclooxygenase inhibitor indomethacin.