title: [The effect of calcitonin gene-related peptide on collagen accumulation in pulmonary arteries of rats with hypoxic pulmonary arterial hypertension].
abstract: OBJECTIVE
  To observe the effect of calcitonin gene-related peptide (CGRP) on pulmonary vascular collagen accumulation in hypoxia rats in order to study the effect of CGRP on hypoxic pulmonary vascular structural remodeling and its possible mechanism.
  
  
  METHODS
  Rats were acclimated for 1 week, and then were randomly divided into three groups: normoxia group, hypoxia group, and hypoxia plus capsaicin group. Pulmonary arterial hypertension was induced by hypoxia in rats. Hypoxia plus capsaicin group, rats were given capsaicin (50 mg/(kg x d), s.c) 4 days before hypoxia to deplete endogenous CGRP. Hypoxia (3% O2) stimulated proliferation of pulmonary arterial smooth muscle cells (PASMCs) and proliferation was measured by BrdU marking. The expression levels of CGRP, phosphorylated ERK1/2 (p-ERK1/ 2), collagen I and collagen III were detected by real-time PCR or Western blot.
  
  
  RESULTS
  Right ventricle systolic pressure (RVSP) and mean pulmonary arterial pressure (mPAP) of pulmonary arterial hypertension (PAH) rats induced by hypoxia were higher than those of normoxia rats. By HE and Masson staining, it was demonstrated that hypoxia also significantly induced hypertrophy of pulmonary arteries and increased level of collagen accumulation. Hypoxia dramatically decreased the CGRP level and increased the expression of p-ERK1/2, collagen I, collagen III in pulmonary arteries. All these effects of hypoxia were further aggravated by pre-treatment of rats with capsaicin. CGRP concentration-dependently inhibited hypoxia-induced proliferation of PASMCs, markedly decreased the expression of p-ERK1/2, collagen I and collagen III. All these effects of CGRP were abolished in the presence of CGRP8-37.
  
  
  CONCLUSIONS
  These results suggest that CGRP might inhibit hypoxia-induced PAH and pulmonary vascular remodeling, through inhibiting phosphorylation of ERK1/2 and alleviating the collagen accumulation of pulmonary arteries.
authors.affiliation: Department of Phamnnacology, Wannan Medical College, Wuhu 241002, China.
authors.forename: Xian-Wei
authors.initials: XW
authors.lastname: Li
authors.forename: Jie
authors.initials: J
authors.lastname: Du
authors.forename: Yuan-Jian
authors.initials: YJ
authors.lastname: Li
mesh_terms: D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000494:pharmacology*; D024042:Collagen Type I / Q000378:metabolism*; D024061:Collagen Type III / Q000378:metabolism*; D065627:Familial Primary Pulmonary Hypertension; D006976:Hypertension, Pulmonary / Q000209:etiology / Q000378:metabolism*; D000860:Hypoxia / Q000150:complications; D020935:MAP Kinase Signaling System; D008297:Male; D010766:Phosphorylation; D011651:Pulmonary Artery / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D024042:Collagen Type I; D024061:Collagen Type III; D015740:Calcitonin Gene-Related Peptide