title: Effects of inhibitor of endothelium-derived relaxing factor on hypoxic contraction of isolated pig coronary artery.
abstract: Exposure of isolated pig coronary artery with endothelium intact to hypoxia Krebs-Henseleit solution aerated with 95% N2 + 5% CO2 caused a transient contractile response, and the coronary artery without endothelium exhibited a gradual decrease in basal tension. The endothelium-dependent contractile response to hypoxia was almost completely blocked by nitro-L-arginine (0.2 mmol.L-1), and inhibited by methylthioninium chloride (10 mumol.L-1). The inhibitory effect of the NLA was partially reversed by L-arginine (2 mmol.L-1). Sodium nitroprusside (10 mumol.L-1) was also completely antagonized and nicorandil (0.3 mol.L-1) remarkably reduced the hypoxic contractile response. Tetraethylammonium (10 mmol.L-1) and glibenclamide (1 mumol.L-1) had little effect on hypoxia-induced vascular contraction, whereas cromakalim (1 mumol.L-1) produced obvious relaxing effect on hypoxic response. These results suggest that suppression of basally released nitric oxide (NO) is an important mechanism of coronary vasoconstriction induced by hypoxia.
authors: Department of Pharmacology, Hebei Medical College, Shijiazhuang, China.
authors: X P
authors: XP
authors: Yang
authors: Z J
authors: ZJ
authors: Wu
authors: Y F
authors: YF
authors: Xu
authors: W
authors: W
authors: Dong
authors: W
authors: W
authors: Yang
authors: S X
authors: SX
authors: Fu
authors: Y S
authors: YS
authors: Li
mesh_terms: D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000494:pharmacology; D001578:Benzopyrans / Q000494:pharmacology; D015687:Cell Hypoxia; D003331:Coronary Vessels / Q000187:drug effects; D019806:Cromakalim; D066298:In Vitro Techniques; D009569:Nitric Oxide / Q000037:antagonists & inhibitors*; D019335:Nitroarginine; D011758:Pyrroles / Q000494:pharmacology; D013552:Swine; D014661:Vasoconstriction / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D001578:Benzopyrans; D011758:Pyrroles; D014665:Vasodilator Agents; D019806:Cromakalim; D019335:Nitroarginine; D009569:Nitric Oxide; D001120:Arginine