title: Omentin, a novel adipokine, induces vasodilation in rat isolated blood vessels.
abstract: Omentin is a recently identified adipose tissue-derived cytokine and is implicated in obesity-related cardiovascular disorders. In the present study, we tested the hypothesis that omentin could directly affect vascular reactivity of isolated blood vessels. In endothelium-intact rat isolated aorta, pretreatment with omentin (300 ng/ml, 30 min) inhibited noradrenaline (NA; 1 nM-1 microM)-induced concentration-dependent contraction. In NA (100 nM)-pre-contracted aorta, omentin (1-300 ng/ml) directly induced an endothelium-dependent relaxation. While a nitric oxide (NO) synthase (NOS) inhibitor, N(G)-nitro-l-arginine methyl ester (100 microM, 30 min) inhibited the relaxation, a PI3K/Akt inhibitor, LY294002 (10 microM, 30 min) or a tyrosine kinase inhibitor, genistein (30 microM, 30 min) was ineffective. Omentin (300 ng/ml, 5 min) induced a phosphorylation of endothelial NOS at serine 1177 but not a phosphorylation of Akt at serine 473. Omentin (1-300 ng/ml) also relaxed NA pre-contracted mesenteric artery. Present study for the first time demonstrated that omentin has a vasodilating effect on isolated blood vessels, which is mediated through endothelium-derived NO.
authors.affiliation: Department of Veterinary Pharmacology, School of Veterinary Medicine, Kitasato University, Towada City, Aomori 034-8628, Japan. yamawaki@vmas.kitasato-u.ac.jp
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Yamawaki
authors.forename: Naoya
authors.initials: N
authors.lastname: Tsubaki
authors.forename: Masashi
authors.initials: M
authors.lastname: Mukohda
authors.forename: Muneyoshi
authors.initials: M
authors.lastname: Okada
authors.forename: Yukio
authors.initials: Y
authors.lastname: Hara
mesh_terms: D054392:Adipokines / Q000494:pharmacology / Q000502:physiology*; D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000502:physiology; D002867:Chromones / Q000494:pharmacology; D016207:Cytokines / Q000494:pharmacology / Q000502:physiology*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D058851:GPI-Linked Proteins; D066298:In Vitro Techniques; D037102:Lectins / Q000494:pharmacology / Q000502:physiology*; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects / Q000502:physiology; D009025:Morpholines / Q000494:pharmacology; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D000081082:Phosphoinositide-3 Kinase Inhibitors; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D014664:Vasodilation
chemical_list: D054392:Adipokines; D002867:Chromones; D016207:Cytokines; D058851:GPI-Linked Proteins; C432397:ITLN1 protein, human; D037102:Lectins; D009025:Morpholines; D000081082:Phosphoinositide-3 Kinase Inhibitors; D047428:Protein Kinase Inhibitors; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one; D019331:NG-Nitroarginine Methyl Ester; D009638:Norepinephrine