title: [The selective dilatation effects of iptakalim on basilar and pulmonary arterioles in high-altitude hypoxic rats].
abstract: OBJECTIVE
  To study the selective dilatation effects of iptakalim (Ipt) on basilar and pulmonary arterioles, and endothelial cell function of these arterioles in hypoxic rats.
  
  
  METHODS
  SD male rats were divided into 2 groups:control and hypoxic group fed in normobaric hypoxic environment (O2 7.8%, 8 h). Arteriole rings about (204 + 5) pm were isolated and the tension of hypoxic arterioles pre-contracted by 6 nmol/L endothelin-1 (ET-1) was observed with wire myograph system model (DMT 610 m). The relaxing response of hypoxic arterioles induced by different concentration of Ipt were detected and endothelial activity was also tested by acetylcholine.
  
  
  RESULTS
  10(5) mol/L acetylcholine (ACh)-mediated vasodilatation of basilar and pulmonary arterioles was greatly reduced in the hypoxic group than those in control group (P < 0.05). Compared with normal group, a novel ATP-sensitive potassium channel opener Ipt at the concentration ranging from 10(-11) mol/L to 10(3) mol/L, caused stronger dose dependent vasodilatation on hypoxic pulmonary arterioles, and there was no significant difference between control and hypoxic basilar arterioles.
  
  
  CONCLUSIONS
  The endothelial function of basilar and pulmonary arterioles was damaged under hypoxic state, and Ipt selectively increased dilatation effects on hypoxic pulmonary arterioles, but not on hypoxic basilar arterioles which could improve high altitude pulmonary edema pathological state and be the novel drug in the treatment of pulmonary hypertension.
authors.forename: Jing-Hui
authors.initials: JH
authors.lastname: Huang
authors.forename: Wen-Zhi
authors.initials: WZ
authors.lastname: Han
authors.forename: Xin
authors.initials: X
authors.lastname: Jin
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Hai
authors.initials: H
authors.lastname: Wang
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000531:Altitude; D000532:Altitude Sickness / Q000503:physiopathology*; D000818:Animals; D001160:Arterioles / Q000187:drug effects*; D004106:Dilatation; D019332:Endothelin-1 / Q000494:pharmacology; D000860:Hypoxia; D054086:KATP Channels / Q000187:drug effects; D008297:Male; D011437:Propylamines / Q000494:pharmacology*; D051381:Rats; D014664:Vasodilation; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D019332:Endothelin-1; D054086:KATP Channels; C502260:N-(1-methylethyl)-1,1,2-trimethylpropylamine; D011437:Propylamines; D014665:Vasodilator Agents; D000109:Acetylcholine