title: Isolated Human Pulmonary Artery Structure and Function Pre- and Post-Cardiopulmonary Bypass Surgery.
abstract: BACKGROUND
  Pulmonary dysfunction is a known complication after cardiac surgery using cardiopulmonary bypass, ranging from subclinical functional changes to prolonged postoperative ventilation, acute lung injury, and acute respiratory distress syndrome. Whether human pulmonary arterial function is compromised is unknown. The aim of the present study was to compare the structure and function of isolated and cannulated human pulmonary arteries obtained from lung biopsies after the chest was opened (pre-cardiopulmonary bypass) to those obtained at the end of cardiopulmonary bypass (post-cardiopulmonary bypass) from patients undergoing coronary artery bypass graft surgery.
  
  
  RESULTS
  Pre- and post-cardiopulmonary bypass lung biopsies were received from 12 patients undergoing elective surgery. Intralobular small arteries were dissected, cannulated, pressurized, and imaged using confocal microscopy. Functionally, the thromboxane mimetic U46619 produced concentration-dependent vasoconstriction in 100% and 75% of pre- and post-cardiopulmonary bypass arteries, respectively. The endothelium-dependent agonist bradykinin stimulated vasodilation in 45% and 33% of arteries pre- and post-cardiopulmonary bypass, respectively. Structurally, in most arteries smooth muscle cells aligned circumferentially; live cell viability revealed that although 100% of smooth muscle and 90% of endothelial cells from pre-cardiopulmonary bypass biopsies had intact membranes and were considered viable, only 60% and 58%, respectively, were viable from post-cardiopulmonary bypass biopsies.
  
  
  CONCLUSIONS
  We successfully investigated isolated pulmonary artery structure and function in fresh lung biopsies from patients undergoing heart surgery. Pulmonary artery contractile tone and endothelium-dependent dilation were significantly reduced in post-cardiopulmonary bypass biopsies. The decreased functional responses were associated with reduced cell viability.
  
  
  BACKGROUND
  URL: http://www.isrctn.com/ISRCTN34428459. Unique identifier: ISRCTN 34428459.
authors.affiliation: Department of Pharmacology, University of Oxford, United Kingdom kim.dora@pharm.ox.ac.uk.
authors.forename: Kim A
authors.initials: KA
authors.lastname: Dora
authors.affiliation: Department of Pharmacology, University of Oxford, United Kingdom.
authors.forename: Christopher P
authors.initials: CP
authors.lastname: Stanley
authors.affiliation: Department of Cardiothoracic Surgery, Hammersmith Hospital, Imperial College London, London, United Kingdom.
authors.forename: Emad
authors.initials: E
authors.lastname: Al Jaaly
authors.affiliation: Department of Cardiothoracic Surgery, Hammersmith Hospital, Imperial College London, London, United Kingdom.
authors.forename: Francesca
authors.initials: F
authors.lastname: Fiorentino
authors.affiliation: Bristol Heart Institute, Bristol Royal Infirmary, University of Bristol, United Kingdom.
authors.forename: Raimondo
authors.initials: R
authors.lastname: Ascione
authors.affiliation: Bristol Heart Institute, Bristol Royal Infirmary, University of Bristol, United Kingdom.
authors.forename: Barnaby C
authors.initials: BC
authors.lastname: Reeves
authors.affiliation: Department of Cardiothoracic Surgery, Hammersmith Hospital, Imperial College London, London, United Kingdom Bristol Heart Institute, Bristol Royal Infirmary, University of Bristol, United Kingdom.
authors.forename: Gianni D
authors.initials: GD
authors.lastname: Angelini
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D002315:Cardiopulmonary Bypass / Q000009:adverse effects; D001026:Coronary Artery Bypass / Q000009:adverse effects; D003324:Coronary Artery Disease / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D004305:Dose-Response Relationship, Drug; D017558:Elective Surgical Procedures; D005260:Female; D006801:Humans; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D011651:Pulmonary Artery / Q000187:drug effects / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome; D014661:Vasoconstriction / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents
keywords: bradykinin; cardiopulmonary bypass; lung; thromboxane; vasoconstriction; vasodilation