COEXPRESSION OF PHOSPHOLIPASE A(2) ISOFORMS IN RAT STRIATAL ASTROCYTES

The expression and activity of phospholipase A(2) (PLA(2)) isoforms we re investigated in primary cultures of striatal astrocytes. The calciu m ionophore A23187 together with the protein kinase C activator phorbo l ester was the most potent stimulus in eliciting [H-3]arachidonic aci d release in the extracellular medium. Reverse transcription coupled t o polymerase chain reaction (RT-PCR) showed the presence of the 85 kDa cytosolic PLA(2) mRNA and the 14 kDa secretory PLA(2) mRNA in untreat ed astrocytes. Immunoblot experiments with isoform-specific antibodies showed the presence of the cytosolic PLA(2) in untreated astrocytes, while the secretory PLA, was detected only in lipopolysaccharide-treat ed astrocytes. These data suggest that the two FLAP isoforms expressed in striatal astrocytes might play different roles in cellular process es mediated by astrocytes. (C) 1998 Elsevier Science Ireland Ltd.