title: [Effects of hypothermia on the concentration of surfactant protein A during endotoxin induced acute lung injury in rats].
abstract: OBJECTIVE
  To investigate the effect of hypothermia (HT) on the concentration of surfactant protein A (SP-A) during lipopolysaccharide (LPS) induced acute lung injury (ALI) in rats.
  
  
  METHODS
  Forty male Wistar rats were randomly divided into three groups. The ALI model was reproduced by LPS intratracheal instillation; only saline was instilled intratracheally for control group. Rats in both model group and control group were sacrificed respectively at 1 hour and 8 hours (each n=8). In HT group the body temperature was lowered to 32.5-33.0 centigrade 1 hour after LPS instillation, and 8 rats were sacrificed at 8 hours. The arterial blood gas was determined in all the groups before and 1 hour and 8 hours after instillation of saline or LPS, and the oxygenation index (PaO(2)/FiO(2)) was calculated. The concentration of SP-A in bronchoalveolar lavage fluid (BALF) was determined by enzyme linked immunosorbent assay. The morphological changes in lung tissue of rats were observed under light microscope.
  
  
  RESULTS
  At 1 hour after intratracheal instillation of LPS, the PaO(2)/FiO(2) of each group reached the diagnostic criterion of ALI. Compared with control 1 hour group, the SP-A (μg/L) in BALF of model 1 hour group was decreased (53.27±1.95 vs. 74.81±6.55, P<0.01); the SP-A in model 8 hour group and HT 8 hour group (4.35±2.76 and 51.36±2.33) was both obviously decreased compared with control 8 hour group (70.81±5.01, both P<0.01). Compared with model 8 hour group, the SP-A of HT 8 hour group was obviously increased (P<0.01). Results of light microscopic examination, it was revealed that the alveolar structure of control 1 hour group and control 8 hour group was almost normal. Inflammatory response in lung tissues in model 8 hour group was found to be most serious; compared with model 8 hour group, inflammatory response in lung tissues in model 1 hour group and HT 8 hour group was reduced in certain degree.
  
  
  CONCLUSIONS
  A certain extent of HT may reduce lung injury of early endotoxin induced ALI rats by delaying lowering of alveolar SP-A levels.
authors.affiliation: Department of Intensive Care Unit , the First Affiliated Hospital of Guangxi Medical University, Nanning 530021, Guangxi, China. tangzhanhong139@sina.com
authors.forename: Zhan-Hong
authors.initials: ZH
authors.lastname: Tang
authors.forename: Xuan
authors.initials: X
authors.lastname: Pan
authors.forename: Jun-Tao
authors.initials: JT
authors.lastname: Hu
authors.forename: Xiao-Fang
authors.initials: XF
authors.lastname: Ji
mesh_terms: D055371:Acute Lung Injury / Q000378:metabolism*; D000818:Animals; D001992:Bronchoalveolar Lavage Fluid; D007035:Hypothermia; D008070:Lipopolysaccharides; D008297:Male; D037662:Pulmonary Surfactant-Associated Protein A / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D008070:Lipopolysaccharides; D037662:Pulmonary Surfactant-Associated Protein A