Adrenomedullin production is correlated with differentiation in human leukemia cell lines and peripheral blood monocytes

We demonstrated that adrenomedullin (ARI) is produced and secreted from human leukemia cell lines (THP-I and HL-60) as well as peripheral blood granulocytes, lymphocytes , monocytes and monocyte-derived macrophages, Immunoreactive ARI accumulated in the culture media of THP-1 and HL-60 cells increased according to their differentiation into macrophage-like cells. Retinoic acid exerted synergistic effects on AM secretion from THP-1 and HL-60 cells when administered with tumor necrosis factor-alpha, lipopolysaccharide or 12-O-tetradecanoyl phorbol-13-acetate, AM was shown to increase the scavenger receptor activity on THP-1 cells. Thus, monocytes/macrophages should be recognized as sources of AM, and the secreted AM may modulate the function of macrophages, (C) 1998 Federation of European Biochemical Societies.