title: [Pulmonary vascular remodeling in hypoxic hypertension in newborn pigs].
abstract: OBJECTIVE
  To determine the pulmonary vascular morphologic changes in small pulmonary arteries of normal development and hypoxic hypertension in newborn pigs.
  
  
  METHODS
  Forty-two pigs aged from the birthday to 14 days were divided into the normal developmental group and hypoxic hypertensive group. Twenty of them were exposed to hypobaric hypoxia (50.8 kPa) for 3 or 11 days to establish a pulmonary hypertension model. With the immunohistochemistric method and tissue slices stained with gamma-actin antibody, small pulmonary artery morphologic changes were analyzed.
  
  
  RESULTS
  In the normal newborn pigs, the percentage of media thickness decreased rapidly; and the ratio of the media area to the lumen area also decreased rapidly during the first 6 days after birth. Hypoxia weakened the decrease of the media thickness percentage and the ratio of the media area to the lumen area during the early period after birth.
  
  
  CONCLUSIONS
  To adapt to the extrauterine life, newborn pigs rapidly remodel pulmonary blood vessels after birth. Hypoxia and hypoxic hypertensions induce abnormal pulmonary vascular remodeling causing pulmonary artery hypertension or making it serious.
authors.affiliation: Department of Cardiothoracic Surgery, Second Xiangya Hospital, Central South University, Changsha 410011, China.
authors.forename: Zhong-shi
authors.initials: ZS
authors.lastname: Wu
authors.forename: Susan M
authors.initials: SM
authors.lastname: Hall
authors.forename: Sheila G
authors.initials: SG
authors.lastname: Haworth
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D006976:Hypertension, Pulmonary / Q000209:etiology / Q000473:pathology*; D000860:Hypoxia / Q000150:complications / Q000473:pathology*; D011651:Pulmonary Artery / Q000473:pathology*