In vitro effect of mercury and vanadium on superoxide anion production and plasminogen activator activity of mouse peritoneal macrophages

The in vitro effects of mercuric chloride and vanadate were examined on two functions of mouse peritoneal macrophages, i.e., the superoxide anion production and the plasminogen activator (PA) activity. Vanadate, at concentrations which do not affect the viability of the cells, does not seriously alter any of these functions. High concentrations of mercury depress the respiratory burst; this effect results from loss of the reducing properties of cellular NADPH. Low concentrations of mercury stimulate the effect of phorbol 12-myristate 13-acetate on PA activity. The mechanism of this stimulation does not involve the protein kinase C system. It is hypothesized that mercury could enhance the synthesis of PA, its translocation to the cell surface, or its binding to the membrane receptors.