title: [Alterations in pulmonary arterial reactivity during pulmonary arterial hypertension at the early-stage of pulmonary fibrosis in rats].
abstract: OBJECTIVE
  To explore the alterations in pulmonary arterial reactivity during pulmonary arterial hypertension at the early-stage of pulmonary fibrosis in rats.
  
  
  METHODS
  Sixty-six male Sprague-Dawley rats were randomly divided into 2 groups: bleomycin (BLM) group and sham group. The rats in BLM group were received single intratracheal instillation of BLM (5 mg/kg), and the rats in sham group received equal volume of 0.9% normal saline (NS). The alterations in pulmonary arterial reactivity were measured by vascular tension detected technique, the pathomorphological changes in the wall of pulmonary arteries were displayed with Hematoxylin-Eosin (HE) staining, the degree of fibrosis in lung was revealed with Masson staining, and the mean pulmonary arterial pressure was detected via a catheter in the pulmonary artery.
  
  
  RESULTS
  (1) The contractile response to a- adrenoceptor agonist phenylephrine (PE), of pulmonary arteries both with remaining endothelium and with removing endothelium, from BLM-treated rats , was reduced significantly, compared with sham rats (P both < 0.05). (2) The relaxant response to the endothelially dependent vasodilator acetylcholine (Ach), of pulmonary arteries with remaining endothelium, from BLM-treated rats, was also reduced, compared with sham rats (P < 0.01). (3) In sham rats, the contractile response to (omega) -nitro-L-arginine methyl ester (L-NAME) plus PE, of pulmonary arteries with remaining endothelium, was enhanced, compared with that to PE alone (P < 0.01), while in BLM group, the contractile responses to L-NAME plus PE, of pulmonary arteries with remaining endothelium, was not different from that to PE alone (P > 0.05). (4) In BLM group, vascular endothelial cells lost. (5) In BLM group, the initial stage of fibrogenesis was observed in lungs, and the mean pulmonary arterial pressure increased, compared with that in sham group (P < 0.05).
  
  
  CONCLUSIONS
  The abnormal responsibility of pulmonary arteries occurred during pulmonary arterial hypertension at the early-stage of pulmonary fibrosis in rats.
authors.affiliation: Department of Pathophysiology, Institute of Basic Medical Sciences, Hebei Medical University, Shijiazhuang 050017, China.
authors.forename: Xiao-Jie
authors.initials: XJ
authors.lastname: Hu
authors.forename: Xiao-Ling
authors.initials: XL
authors.lastname: Chen
authors.forename: Chao
authors.initials: C
authors.lastname: Chen
authors.forename: Jie
authors.initials: J
authors.lastname: Ai
authors.forename: Jia
authors.initials: J
authors.lastname: Li
authors.forename: Xiao-Jing
authors.initials: XJ
authors.lastname: Han
mesh_terms: D000818:Animals; D065627:Familial Primary Pulmonary Hypertension; D006976:Hypertension, Pulmonary / Q000150:complications / Q000503:physiopathology*; D008297:Male; D011651:Pulmonary Artery / Q000503:physiopathology*; D011658:Pulmonary Fibrosis / Q000150:complications / Q000503:physiopathology*; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D014666:Vasomotor System / Q000502:physiology*