Low extracellular Mg2+ concentrations suppress phagocytosis in vitro by alveolar macrophages from rats.

ABSTRACT

The aim of this study was to assess the effects of extracellular Mg2+ concentrations on phagocytosis in vitro by alveolar macrophages from rats. Phagocytosis was suppressed in the presence of low, but not high, Mg2+ concentrations. Vanadate, a Mg(2+)-ATPase inhibitor, suppressed phagocytosis. In the presence of a low Mg2+ concentration or vanadate, the cytosolic free Ca2+ concentration ([Ca2+]i) increased, but the cytosolic free Mg2+ concentration did not. These results suggest that low extracellular Mg2+ concentrations and vanadate suppress phagocytosis by rat alveolar macrophages by increasing [Ca2+]i.