title: [The effect of niflumic acid in hypoxic hypercapnia pulmonary vasoconstriction].
abstract: OBJECTIVE
  To investigate the effect of chloride channel blocker--niflumic acid (NFA) on the pathological process of hypoxia hypercapnia-induced pulmonary vasoconstriction in rats.
  
  
  METHODS
  We used the model of hypoxia hypercapnia-induced pulmonary vasoconstriction rats, and divided the second, third branch pulmonary artery rings randomly into four groups (n = 8): control group (N group), hypoxia hypercapnia group (H group), DMSO incubation group (HD group), niflumic acid group (NFA group). Under acute hypoxia hypercapnia conditions, we observed the effects of the three stages of hypoxia hypercapnia-induced pulmonary vasoconstriction (HHPV) incubated by NFA in the second, third brach pulmonary artery rings. At the same time, the values of rings' tension changings were recorded via the method of hypoxia hypercapnia conditions reactivity. And investigated the effect of NFA to HHPV.
  
  
  RESULTS
  (1) Under the hypoxia hypercapnia condition, we observed a biphasic pulmonary artery contractile (the phase I rapid contraction and vasodilation; the phase II sustained contraction) response in both the second and the third branch pulmonary artery rings compared with the control group (P < 0.05 , P < 0.01); (2) The second and third pulmonary artery rings incubated by NFA which phase II persistent vasoconstriction were significantly attenuated compared with the H group (P < 0.05 , P < 0.01).
  
  
  CONCLUSIONS
  The blocker of the chloride channels attenuates the second and third branch pulmonary artery rings constriction in rat, especially the phase II persistent vasoconstriction, so then have an antagonistic effect on HHPV.
authors.forename: Lin-Jing
authors.initials: LJ
authors.lastname: Huang
authors.forename: Jin-Bo
authors.initials: JB
authors.lastname: He
authors.forename: Shu-Jun
authors.initials: SJ
authors.lastname: Wang
authors.forename: Ying-Chun
authors.initials: YC
authors.lastname: Ma
authors.forename: Lei
authors.initials: L
authors.lastname: Ying
authors.forename: Yang
authors.initials: Y
authors.lastname: Wang
authors.forename: Wan-Tie
authors.initials: WT
authors.lastname: Wang
mesh_terms: D000818:Animals; D018118:Chloride Channels / Q000037:antagonists & inhibitors; D006935:Hypercapnia / Q000503:physiopathology*; D000860:Hypoxia / Q000503:physiopathology*; D009544:Niflumic Acid / Q000494:pharmacology*; D011651:Pulmonary Artery / Q000503:physiopathology; D011652:Pulmonary Circulation; D051381:Rats; D014661:Vasoconstriction / Q000187:drug effects*
chemical_list: D018118:Chloride Channels; D009544:Niflumic Acid