title: Agmatine: a novel endogenous vasodilator substance.
abstract: The purpose of the study was to investigate the effects of agmatine, an endogenous clonidine-displacing substance (CDS), on systemic hemodynamics in the anesthetized rat. Bolus intravenous (i.v.) injections of agmatine decreased systemic arterial pressure (SAP) and systemic vascular resistance in a dose-dependent manner. The development of acute tachyphylaxis to the systemic vasodepressor response to agmatine did not induce cross-tachyphylaxis to the systemic vasodepressor responses to bradykinin, isoproterenol and nitroglycerin. The present data demonstrate agmatine, as a CDS and agonist for imidazoline (I) receptors, possesses marked systemic vasodilator activity in the rat. The present data suggest that activation of I receptors may represent a novel mechanism of vasodilation in vivo.
authors.affiliation: Department of Surgery, Tulane University School of Medicine, New Orleans, LA 70112, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Gao
authors.forename: B
authors.initials: B
authors.lastname: Gumusel
authors.forename: G
authors.initials: G
authors.lastname: Koves
authors.forename: A
authors.initials: A
authors.lastname: Prasad
authors.forename: Q
authors.initials: Q
authors.lastname: Hao
authors.forename: A
authors.initials: A
authors.lastname: Hyman
authors.forename: H
authors.initials: H
authors.lastname: Lippton
mesh_terms: D000376:Agmatine / Q000494:pharmacology*; D000818:Animals; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D013618:Tachyphylaxis; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D014665:Vasodilator Agents; D000376:Agmatine