title: Lung surfactant function and composition in neonatal foals and adult horses.
abstract: BACKGROUND
  Lung surfactant function and composition are varied and adapted to the specific respiratory physiology of all mammalian species.
  
  
  OBJECTIVE
  Lung surfactant function and composition are different in neonatal foals as compared to adult horses.
  
  
  METHODS
  Six adult horses, 7 term foals (<24 hours old), and 4 premature foals were used. Animals were part of the Auburn University teaching herd except for 3 client-owned premature foals.
  
  
  METHODS
  Bronchoalveolar lavage fluid (BALF) was obtained from all animals. Ultracentrifugation of cell-free BALF separated surfactant into crude surfactant pellets (CSP) and supernatant. Both fractions were analyzed for phospholipid and protein content with the Bartlett and bicinchoninic acid method, respectively. Phospholipid composition of the CSP was determined by using high-performance liquid chromatography with an evaporative light scatter detector. Surface tension of the CSP was measured with a pulsating bubble surfactometer. Results from term foals (<24 hours old) were compared statistically to those from adult horses. Values of P < .05 were considered significant.
  
  
  RESULTS
  BALF phospholipid content was similar between adult horses and term foals, but BALF protein content was significantly decreased in term foals. Phosphatidylglycerol was significantly decreased, phosphatidylinositol was significantly increased, and the minimum surface tension was significantly increased in the CSP from term foals compared to adult horses.
  
  
  CONCLUSIONS
  Surface tension and phospholipid composition of surfactant in neonatal foals are significantly different compared to adult horses. These changes may influence biophysical and immunologic functions of surfactant.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, AL, USA. chrisun@vt.edu
authors.forename: Undine
authors.initials: U
authors.lastname: Christmann
authors.forename: Leanda C
authors.initials: LC
authors.lastname: Livesey
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Taintor
authors.forename: Bryan M
authors.initials: BM
authors.lastname: Waldridge
authors.forename: John
authors.initials: J
authors.lastname: Schumacher
authors.forename: Bonnie L
authors.initials: BL
authors.lastname: Grier
authors.forename: R Duncan
authors.initials: RD
authors.lastname: Hite
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry* / Q000166:cytology; D002851:Chromatography, High Pressure Liquid / Q000379:methods / Q000662:veterinary; D005260:Female; D006736:Horses; D008168:Lung / Q000378:metabolism* / Q000502:physiology; D008297:Male; D010743:Phospholipids / Q000032:analysis* / Q000378:metabolism; D037661:Pulmonary Surfactant-Associated Proteins / Q000032:analysis* / Q000378:metabolism; D011663:Pulmonary Surfactants / Q000032:analysis* / Q000378:metabolism; D012129:Respiratory Function Tests
chemical_list: D010743:Phospholipids; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants