In VitroEffectof @ 2 - Agonistson Bacterial KillingandSuperoxideAnion ( 02 )

man tissues and blood cells. In particular, @32adrenergic receptor effects on lymphocytes and gran ulocytes have been probed extensively.' Recently, Liggett2 identified and characterized @32-adrenergic receptors in human alveolar macrophages responding to specific stimulation with an increase of intracellular cyclic adenosine monophosphate (cAMP). This increase in cAMP has striking inhibitory effects on alveolar macrophage functions such as lysosomal content release,3 migration,4 phagocytosis,5 calcium dependent Na@/K@ pump,6 and oxygen-free radical production.7― Most of these studies were carried out on alveolar macrophages from animals. Few reports on human lung macrophage activities have been published and the results are often controversial. The defensive role of alveolar macrophages is of primary importance, but an excessive release of in flammatory mediators can cause damage to lung tissues. The understanding ofwhat may condition the