title: Postnatal estradiol up-regulates lung nitric oxide synthases and improves lung function in bronchopulmonary dysplasia.
abstract: BACKGROUND
  Nitric oxide (NO) plays an important role in lung development and perinatal lung function, and pulmonary NO synthases (NOS) are decreased in bronchopulmonary dysplasia (BPD) following preterm birth. Fetal estradiol levels increase during late gestation and estradiol up-regulates NOS, suggesting that after preterm birth estradiol deprivation causes attenuated lung NOS resulting in impaired pulmonary function.
  
  
  OBJECTIVE
  To test the effects of postnatal estradiol administration in a primate model of BPD over 14 days after delivery at 125 days of gestation (term = 185 d).
  
  
  METHODS
  Cardiopulmonary function was assessed by echocardiography and whole body plethysmography. Lung morphometric and histopathologic analyses were performed, and NOS enzymatic activity and abundance were measured.
  
  
  RESULTS
  Estradiol caused an increase in blood pressure and ductus arteriosus closure. Expiratory resistance and lung compliance were also improved, and this occurred before spontaneous ductal closure. Furthermore, both oxygenation and ventilation indices were improved with estradiol, and the changes in lung function and ventilatory support requirements persisted throughout the study period. Whereas estradiol had negligible effect on indicators of lung inflammation and on lung structure assessed after the initial 14 days of ventilatory support, it caused an increase in lung neuronal and endothelial NOS enzymatic activity.
  
  
  CONCLUSIONS
  In a primate model of BPD, postnatal estradiol treatment had favorable cardiovascular impact, enhanced pulmonary function, and lowered requirements for ventilatory support in association with an up-regulation of lung NOS. Estradiol may be an efficacious postnatal therapy to improve lung function and outcome in preterm infants.
authors.affiliation: Department of Pediatrics, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA.
authors.forename: Donald C
authors.initials: DC
authors.lastname: McCurnin
authors.forename: Richard A
authors.initials: RA
authors.lastname: Pierce
authors.forename: Brigham C
authors.initials: BC
authors.lastname: Willis
authors.forename: Ling Yi
authors.initials: LY
authors.lastname: Chang
authors.forename: Bradley A
authors.initials: BA
authors.lastname: Yoder
authors.forename: Ivan S
authors.initials: IS
authors.lastname: Yuhanna
authors.forename: Philip L
authors.initials: PL
authors.lastname: Ballard
authors.forename: Ronald I
authors.initials: RI
authors.lastname: Clyman
authors.forename: Nahid
authors.initials: N
authors.lastname: Waleh
authors.forename: William
authors.initials: W
authors.lastname: Maniscalco
authors.forename: James D
authors.initials: JD
authors.lastname: Crapo
authors.forename: Peter H
authors.initials: PH
authors.lastname: Grubb
authors.forename: Philip W
authors.initials: PW
authors.lastname: Shaul
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001794:Blood Pressure / Q000187:drug effects; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D001997:Bronchopulmonary Dysplasia / Q000628:therapy*; D004195:Disease Models, Animal; D004373:Ductus Arteriosus / Q000187:drug effects; D004549:Elastin / Q000235:genetics / Q000378:metabolism; D004958:Estradiol / Q000097:blood / Q000494:pharmacology*; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008168:Lung / Q000378:metabolism / Q000473:pathology; D008170:Lung Compliance; D008297:Male; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D010100:Oxygen / Q000097:blood; D010215:Papio; D011663:Pulmonary Surfactants / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011897:Random Allocation; D011959:Receptors, Estradiol / Q000378:metabolism; D012121:Respiration, Artificial; D015854:Up-Regulation
chemical_list: D004967:Estrogens; D011663:Pulmonary Surfactants; D012333:RNA, Messenger; D011959:Receptors, Estradiol; D004958:Estradiol; D004549:Elastin; D019001:Nitric Oxide Synthase; D010100:Oxygen