PRESENCE OF ARGININOSUCCINATE SYNTHETASE IN GLIAL-CELLS AS REVEALED BY PEPTIDE-SPECIFIC ANTISERA

The presence and the possibility of induction of argininosuccinate syn thetase in a glial cell line were investigated. For this purpose, anti sera were produced against peptides representing partial sequences 196 -222 and 337-349, respectively, of the mouse liver enzyme. Both antise ra were shown to be monospecific for argininosuccinate synthetase. In Western blot experiments, immunoreactivity was found in mouse liver an d brain homogenates. Only weak immunoreactivity was detectable in homo genates of cultured glioma cells, C6-BU-1. However, when the glioma ce lls were treated with either bacterial lipopolysaccharide, interferon- gamma, or a combination of both, argininosuccinate synthetase immunore activity was increased. The findings demonstrate that this enzyme is p resent in glial cells and is induced under conditions which stimulate persistent production of nitric oxide. The antisera will be a valuable tool for further investigations on arginine synthesis in brain as wel l as peripheral cells.