N-G-NITRO-L-ARGININE METHYL-ESTER REDUCES NECROTIC BUT NOT APOPTOTIC CELL-DEATH INDUCED BY REVERSIBLE FOCAL ISCHEMIA IN RAT

During cerebral ischemia, nitric oxide (NO) production via stimulation of NO synthase, is likely one of the major events leading to neuronal death. Recently, we have demonstrated that after reversible focal isc hemia, apoptosis was implicated in the penumbra whereas necrosis was p rominent in the ischemic core. We have now examined the effect of a no n-specific inhibitor of NO synthase, N-G-nitro-L-arginine methyl ester (L-NAME, 3 mg kg(-1) i.p., 5 min and 3 h after the onset of ischemia) , on the progress of apoptotic and necrotic nuclei following transient focal cerebral ischemia, using DNA electrophoresis and terminal deoxy nucleotidyl transferase (TdT)-mediated dUTP-biotin nick-end labelling (TUNEL assay). Our results indicated that L-NAME prevented the loss of necrotic, but not apoptotic cells.