Neuroprotective efficacy of N omega-nitro-L-arginine after focal cerebral ischemia in the mouse and inhibition of cortical nitric oxide synthase.

Abstract

The neuroprotective effects of various doses of N omega-nitro-L-arginine have been correlated with the degree of N omega-nitro-L-arginine-induced inhibition of cortical nitric oxide synthase activity measured ex vivo. Following focal cerebral ischemia induced by permanent occlusion of middle cerebral artery in the mouse, repeated administration of 1 mg/kg i.p. of N omega-nitro-L-arginine (beginning 5 min after surgery) reproducibly decreased by 66-76% the infarct volume measured at 6 days post-occlusion. This dose of N omega-nitro-L-arginine decreased cortical nitric oxide (NO) synthase activity by 70-73%. The neuroprotective efficacy of N omega-nitro-L-arginine increased dose-dependently over the range of doses of 0.1-1 mg/kg. Within this dose range of N omega-nitro-L-arginine, there was a good parallelism between the extent of inhibition of cortical NO synthase activity measured ex vivo and the degree of neuroprotection. However, higher doses of N omega-nitro-L-arginine (3 and 10 mg/kg i.p.), which inhibited NO synthase activity more effectively (up to 94%) failed to significantly reduce the infarct size. Repeated administrations of increasing doses of L-arginine (up to 30 mg/kg i.p.) with a low dose of N omega-nitro-L-arginine (1 mg/kg i.p.) caused a dose-dependent reduction in the neuroprotective efficacy of N omega-nitro-L-arginine while the extent of NO synthase inhibition measured ex vivo did not decrease significantly.(ABSTRACT TRUNCATED AT 250 WORDS)

• Authors: A Carreau, D Duval, H Poignet, B Scatton, X Vigé, J P Nowicki
• Journal: European journal of pharmacology (Eur J Pharmacol) Vol. 256 Issue 3 Pg. 241-9 (May 02 1994) ISSN: 0014-2999 [Print] Netherlands
• PMID: 7519148 (Publication Type: Journal Article)

Chemical References

• Nitroarginine
• Arginine
• Nitric Oxide Synthase
• Amino Acid Oxidoreductases

Topics

• Amino Acid Oxidoreductases (antagonists & inhibitors, metabolism)
• Animals
• Arginine (analogs & derivatives, pharmacology, therapeutic use)
• Brain Ischemia (complications, enzymology)
• Cerebral Cortex (enzymology)
• Cerebral Infarction (prevention & control)
• Dose-Response Relationship, Drug
• Injections, Intraperitoneal
• Male
• Mice
• Nitric Oxide Synthase
• Nitroarginine