ADRENOMEDULLIN INHIBITS THE SECRETION OF CYTOKINE-INDUCED NEUTROPHIL CHEMOATTRACTANT, A MEMBER OF THE INTERLEUKIN-8 FAMILY, FROM RAT ALVEOLAR MACROPHAGES

This study was undertaken to determine the effects of adrenomedullin ( AM) on the secretion of cytokine-induced neutrophil chemoattractant (C INC), a member of the interleukin-8 family, from lipopolysaccharide-st imulated rat alveolar macrophages in vitro. AM significantly increased cAMP levels in alveolar macrophages in a dose-dependent fashion. On t he other hand, AM significantly inhibited CINC secretion from alveolar macrophages in a dose-dependent fashion, and 8-bromo-cyclic adenosine monophosphate (8-Br-cAMP) also significantly inhibited CINC secretion . These findings suggest that AM may play important roles in the regul ation of airway inflammation via a cAMP-dependent mechanism. (C) 1995 Academic Press, Inc.