INDUCTION OF MANGANESE SUPEROXIDE-DISMUTASE IN BV-2 MICROGLIAL CELLS

THE regulation of the manganese-dependent superoxide dismutase (Mn-SOD ) was studied in immortalized microglial cells (line BV-2). BV-2 cells , activated with lipopolysaccharide (LPS), exhibited an increase in Mn -SOD-like immunoreactivity, that was associated with an accumulation o f nitrite in the culture medium and an increase in immunoreactivity fo r the inducible type of nitric oxide synthase (i-NOS). The i-NOS inhib itor L-N-6-(1-iminoethyl)-lysine (NIL, 600 mu M) suppressed the nitrit e accumulation and the increase in Mn-SOD-like immunoreactivity in act ivated cells without significant effect on the level of i-NOS-like imm unoreactivity. The NO donor sodium nitroprusside dose-dependently incr eased Mn-SOD-like immunoreactivity in NIL-pretreated BV-2 cells. These results indicate that the induction of Mn-SOD in activated BV-2 cells is mediated in part by NO, or its metabolites.