title: Inhibition of nitric oxide formation by guanidines.
abstract: Aminoguanidine, N,N'-diaminoguanidine, methylguanidine, and 1,1-dimethylguanidine were compared to NG-monomethyl-L-arginine (L-NMMA) for their ability to inhibit nitric oxide (NO) formation by cytokine-inducible and vascular constitutive isoforms of NO synthase. These comparisons were performed by assessing (1) cytokine-induced production of nitrite by RINm5F cells, (2) vasoconstrictor responses of isolated rat mesenteric arteries, and (3) in vivo blood pressure responses following intravenous bolus injection into anesthetized rats. Aminoguanidine and L-NMMA were the most potent inhibitors of cytokine-induced NO formation in RINm5F cells, while the other guanidine compounds were 10 (1,1-dimethylguanidine) to 100 (methylguanidine) times less potent. L-NMMA and 1,1-dimethylguanidine were the most potent inhibitors of the vascular constitutive isoform of NO synthase in both assay systems, while aminoguanidine and N,N'-diaminoguanidine were the least potent. These results (1) confirm the selective inhibition of the inducible isoform of NO synthase by aminoguanidine, (2) indicate that N,N'-diaminoguanidine, while approximately 30 times less potent than aminoguanidine in inhibiting inducible NO synthase, has very little effect on constitutive NO synthase activity, and (3) 1,1-dimethylguanidine, like L-NMMA, is a relatively potent inhibitor of both isoforms of NO synthase.
authors.affiliation: Department of Pathology, Washington University School of Medicine, Saint Louis, MO 63110.
authors.forename: K
authors.initials: K
authors.lastname: Hasan
authors.forename: B J
authors.initials: BJ
authors.lastname: Heesen
authors.forename: J A
authors.initials: JA
authors.lastname: Corbett
authors.forename: M L
authors.initials: ML
authors.lastname: McDaniel
authors.forename: K
authors.initials: K
authors.lastname: Chang
authors.forename: W
authors.initials: W
authors.lastname: Allison
authors.forename: B H
authors.initials: BH
authors.lastname: Wolffenbuttel
authors.forename: J R
authors.initials: JR
authors.lastname: Williamson
authors.forename: R G
authors.initials: RG
authors.lastname: Tilton
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000037:antagonists & inhibitors*; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D001794:Blood Pressure / Q000187:drug effects*; D002460:Cell Line; D006146:Guanidines / Q000494:pharmacology*; D066298:In Vitro Techniques; D007375:Interleukin-1 / Q000494:pharmacology; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects; D008760:Methylguanidine / Q000031:analogs & derivatives / Q000494:pharmacology; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase; D009573:Nitrites / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D014661:Vasoconstriction / Q000187:drug effects*; D019323:omega-N-Methylarginine
chemical_list: D006146:Guanidines; D007375:Interleukin-1; D009573:Nitrites; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; C003899:1,3-dimethylguanidine; C070130:diaminoguanidine; D008760:Methylguanidine; D001120:Arginine; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; C004479:pimagedine