title: Disaturated-phosphatidylcholine and surfactant protein-B turnover in human acute lung injury and in control patients.
abstract: BACKGROUND
  Patients with adult respiratory distress syndrome (ARDS) and acute lung injury (ALI) have low concentrations of disaturated-phosphatidylcholine and surfactant protein-B in bronchoalveolar lavage fluid. No information is available on their turnover.
  
  
  OBJECTIVE
  To analyze disaturated-phosphatidylcholine and surfactant protein-B turnover in patients with ARDS/ALI and in human adults with normal lungs (controls).
  
  
  METHODS
  2H2O as precursor of disaturated-phosphatidylcholine-palmitate and 113C-Leucine as precursor of surfactant protein-B were administered intravenously to 12 patients with ARDS/ALI and to 8 controls. Disaturated-phosphatidylcholine and surfactant protein-B were isolated from serial tracheal aspirates, and their fractional synthetic rate was derived from the 2H and 13C enrichment curves, obtained by gas chromatography mass spectrometry. Disaturated-phosphatidylcholine, surfactant protein-B, and protein concentrations in tracheal aspirates were also measured.
  
  
  RESULTS
  1) Surfactant protein-B turned over at faster rate than disaturated-phosphatidylcholine both in ARDS/ALI patients and in controls. 2) In patients with ARDS/ALI the fractional synthesis rate of disaturated-phosphatidylcholine was 3.1 times higher than in controls (p < 0.01), while the fractional synthesis rate of surfactant protein-B was not different. 3) In ARDS/ALI patients the concentrations of disaturated-phosphatidylcholine and surfactant protein-B in tracheal aspirates were markedly and significantly reduced (17% and 40% of the control values respectively).
  
  
  CONCLUSIONS
  1) Disaturated-phosphatidylcholine and surfactant protein-B have a different turnover both in healthy and diseased lungs. 2) In ARDS/ALI the synthesis of these two surfactant components may be differently regulated.
authors.affiliation: Department of Pediatrics, University of Padova, Padova, Italy.
authors.forename: Manuela
authors.initials: M
authors.lastname: Simonato
authors.forename: Aldo
authors.initials: A
authors.lastname: Baritussio
authors.forename: Carlo
authors.initials: C
authors.lastname: Ori
authors.forename: Luca
authors.initials: L
authors.lastname: Vedovelli
authors.forename: Sandra
authors.initials: S
authors.lastname: Rossi
authors.forename: Lorenza
authors.initials: L
authors.lastname: Dalla Massara
authors.forename: Sabina
authors.initials: S
authors.lastname: Rizzi
authors.forename: Virgilio P
authors.initials: VP
authors.lastname: Carnielli
authors.forename: Paola E
authors.initials: PE
authors.lastname: Cogo
mesh_terms: D055371:Acute Lung Injury / Q000378:metabolism*; D000328:Adult; D015415:Biomarkers / Q000378:metabolism; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007558:Italy; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D010713:Phosphatidylcholines / Q000096:biosynthesis / Q000378:metabolism*; D037701:Pulmonary Surfactant-Associated Protein B / Q000096:biosynthesis / Q000378:metabolism*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D010713:Phosphatidylcholines; D037701:Pulmonary Surfactant-Associated Protein B; C017463:lecithins, disaturated