NITROPRUSSIDE IMPROVES BLOOD-FLOW AND REDUCES BRAIN-DAMAGE AFTER FOCAL ISCHEMIA

WE used the nitric oxide (NO) donor sodium nitroprusside (SNP) and the NO synthase inhibitor nitro-L-arginine methyl ester (L-NAME) to study the role of NO in the ischemic damage produced by occlusion of the ra t middle cerebral artery (MCA). After MCA occlusion, intracarotid admi nistration of SNP (2.5 mg kg h-2 for 1 h) enhanced the recovery of neo cortical cerebral blood flow and of the EEG and reduced cortical infar ct size by 76 +/- 2% (P < 0.01; n = 5). In contrast, administration of L-NAME (10 mg kg h-2) worsened the recovery of CBF and EEG and increa sed infarct size (+ 60 +/- 16%; P < 0.05; n = 5). The findings indicat e that NO improves blood flow and reduces tissue damage after focal ce rebral ischemia. Thus, NO donors could have an important role in the m anagement of acute ischemic stroke.