Vasodilative action of carbon monoxide on rat pulmonary artery in vitro.
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.
Ding
Xue-Qin
XQ
Department of Anesthesiology, The First Affiliated Hospital, China Medical University, Shenyang 110001, xueqinding@yahoo.com
Liu
Gui-Ming
GM
Wang
Jun-Ke
JK
Sheng
Zhuo-Ren
ZR
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*
D011524:Protoporphyrins; C017803:zinc protoporphyrin; D002248:Carbon Monoxide; D019001:Nitric Oxide Synthase; D006419:Heme Oxygenase (Decyclizing); D000109:Acetylcholine; D019331:NG-Nitroarginine Methyl Ester