title: Composition of alveolar surfactant changes with training in humans.
abstract: OBJECTIVE
  We test the hypothesis that the changes we observed previously in the relative amounts of disaturated phospholipids (DSP), cholesterol (CHOL), and surfactant protein-A (SP-A) in human alveolar surfactant in response to acute exercise, and which were related to fitness, can be induced by training.
  
  
  METHODS
  We examine the effect of 7 weeks' training on these major surfactant components, together with surfactant protein-B (SP-B), in bronchoalveolar lavage fluid harvested from 17 males, both at rest and after acute exercise. Fitness was assessed as workload/heart rate achieved during cycling for 30 min at 90% of theoretical maximal heart rate, and was increased in all subjects following training (mean increase 22.2+/-3.91%; P = 0.001).
  
  
  RESULTS
  Training significantly increased the SP-A/DSP, SP-B/DSP, SP-A/CHOL and SP-A/SP-B ratios in whole surfactant harvested from subjects both at rest and immediately following exercise. Training also increased the SP-B/CHOL ratio at rest. Changes were particularly marked at rest in the SP-A/DSP, SP-A/CHOL, and SP-B/CHOL ratios in the tubular myelin-rich fraction, and after exercise in the SP-A/DSP, SP-A/CHOL, and SP-A/SP-B ratios in the tubular myelin-poor fraction.
  
  
  CONCLUSIONS
  We conclude that training markedly alters the composition of alveolar surfactant both at rest and with exercise; the physiological significance of these changes remains to be determined.
authors.affiliation: Department of Human Physiology, School of Medicine, Flinders University, Adelaide, South Australia, Australia.
authors.forename: I R
authors.initials: IR
authors.lastname: Doyle
authors.forename: S
authors.initials: S
authors.lastname: Morton
authors.forename: A J
authors.initials: AJ
authors.lastname: Crockett
authors.forename: H A
authors.initials: HA
authors.lastname: Barr
authors.forename: K G
authors.initials: KG
authors.lastname: Davidson
authors.forename: M J
authors.initials: MJ
authors.lastname: Jones
authors.forename: M E
authors.initials: ME
authors.lastname: Jones
authors.forename: T E
authors.initials: TE
authors.lastname: Nicholas
mesh_terms: D000293:Adolescent; D000328:Adult; D018893:Bronchoalveolar Lavage; D002784:Cholesterol / Q000032:analysis / Q000097:blood; D015444:Exercise / Q000502:physiology*; D006801:Humans; D008055:Lipids / Q000097:blood; D008297:Male; D010743:Phospholipids / Q000032:analysis; D010806:Physical Education and Training; D010809:Physical Fitness / Q000502:physiology*; D011510:Proteolipids / Q000032:analysis; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000032:analysis / Q000737:chemistry*; D015203:Reproducibility of Results; D012119:Respiration; D012146:Rest / Q000502:physiology
chemical_list: D008055:Lipids; D010743:Phospholipids; D011510:Proteolipids; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants; D002784:Cholesterol