ADRENOMEDULLIN PRODUCTION IS CORRELATED WITH DIFFERENTIATION IN HUMANLEUKEMIA-CELL LINES AND PERIPHERAL-BLOOD MONOCYTES

We demonstrated that adrenomedullin (ARI) is produced and secreted fro m human leukemia cell lines (THP-I and HL-60) as well as peripheral bl ood granulocytes, lymphocytes , monocytes and monocyte-derived macroph ages, Immunoreactive ARI accumulated in the culture media of THP-1 and HL-60 cells increased according to their differentiation into macroph age-like cells. Retinoic acid exerted synergistic effects on AM secret ion from THP-1 and HL-60 cells when administered with tumor necrosis f actor-alpha, lipopolysaccharide or 12-O-tetradecanoyl phorbol-13-aceta te, 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.