Beta-adrenoceptor-effector system of the human macrophage U937 cell line

Like animal peritoneal macrophages, cells of the U937 human macrophage cell line were found to possess beta-adrenoceptors with a density of approximately 1400 sites/cell of the beta 2-subtype. Agonist occupancy increased adenylate cyclase activity and lead to rapid sequestration of cell surface receptors, functional desensitization, and receptor downregulation. Thus human macrophages possess beta-adrenoceptors and the U937 cell provides a system for studying the interactions of this receptor with macrophage immune function.