title: Vasodilative action of carbon monoxide on rat pulmonary artery in vitro.
abstract: The present study investigates the vasodilative action of carbon monoxide on rat pulmonary artery in vitro. After isolation of the pulmonary artery rings (PAR) from Wistar rats, an ACh concentration-response curve was generated; the PARs were incubated with the NOS inhibitor L-NAME (30 micromol/L, n=10) or the heme oxygenase inhibitor ZnPPIX (10 micromol/L)+L-NAME (30 micromol/L, n=10) for 30 min. After that, a second ACh concentration-response curve was elicited. Other isolated PARs were randomly divided into two groups: endothelium-intact group (n=8) and endothelium-denuded group (n=8). The effect of exogenous carbon monoxide (CO) on pulmonary arterial vessel tone was observed. The results showed that ACh induced a concentration-dependent pulmonary vasorelaxation. This relaxation disappeared after endothelium was denuded. The ACh induced relaxation was attenuated after pretreatment with 30 micromol/L L-NAME, and attenuated further after pretreatment with 10 micromol/L ZnPPIX+30 micromol/L L-NAME. Exogenous carbon monoxide relaxed pulmonary artery in both the endothelium-intact group and the endothelium-denuded group. These data suggest that ZnPPIX inhibits ACh induced endothelium-dependent pulmonary artery relaxation and that CO is an endothelium-derived relaxation factor, and exogenous CO can relax pulmonary artery.
authors.affiliation: Department of Anesthesiology, The First Affiliated Hospital, China Medical University, Shenyang 110001, xueqinding@yahoo.com
authors.forename: Xue-Qin
authors.initials: XQ
authors.lastname: Ding
authors.forename: Gui-Ming
authors.initials: GM
authors.lastname: Liu
authors.forename: Jun-Ke
authors.initials: JK
authors.lastname: Wang
authors.forename: Zhuo-Ren
authors.initials: ZR
authors.lastname: Sheng
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D002248:Carbon Monoxide / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000187:drug effects; D006419:Heme Oxygenase (Decyclizing) / Q000037:antagonists & inhibitors; D066298:In Vitro Techniques; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D011524:Protoporphyrins / Q000494:pharmacology; D011651:Pulmonary Artery / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D014664:Vasodilation / Q000187:drug effects*
chemical_list: D011524:Protoporphyrins; C017803:zinc protoporphyrin; D002248:Carbon Monoxide; D019001:Nitric Oxide Synthase; D006419:Heme Oxygenase (Decyclizing); D000109:Acetylcholine; D019331:NG-Nitroarginine Methyl Ester