DELETERIOUS CA-INDEPENDENT NOS ACTIVITY AFTER OXIDATIVE STRESS IN RATSTRIATUM

THE aim of this study was to assess whether oxidative stress induces d eleterious NOS activity in the central nervous system (CNS). For this purpose, the mitochondrial toxin malonate, which promotes free radical production, was infused into the left striatum of rats. Forty-eight h ours after injection, an increase in Ca-independent NOS activity was o bserved in the injected striatum. This increase was blocked by alpha-p henyl-tert-butyl-nitrone, a free radical scavenger, and by aminoguanid ine, an inhibitor of NOS 2. Both these drugs reduced the malonate-indu ced striatal necrotic volume. These results suggest that in the CNS ox idative stress can induce a Ca-independent NOS, probably of type 2, wh ich contributes to the lesion.