title: [The effects of three dosages of nebulized unfractionated heparin on alveolar coagulation and tissue inflammation injury in endotoxin-induced acute lung injury rat model].
abstract: OBJECTIVE
  To observe the effects of three dosages of nebulized unfractionated heparin (UFH) on alveolar coagulation, inflammation and lung histology in endotoxin-induced acute lung injury rat model, and investigate the appropriated dose of local UFH in managing intrapulmonary coagulopathy.
  
  
  METHODS
  Twenty-nine male Wistar rats were divided into control (n=5) and UFH group (n=24) in table of random number, which were duplicated to be endotoxin-induced ALI rat model with lipopolysaccharide (LPS) injecting by intravenous route. The UFH group was divided into three subgroups, which were administered once with 6, 12 and 18 U/g aerosolized UFH in 10 ml at 2 hours after challenge, respectively, while the control group was simply nebulized with normal saline. All rats were sacrificed at 6 hours after intravenous administration of LPS, bronchoalveolar lavage was performed, and the fluid was collected. Enzyme-linked immune sorbent assay (ELISA) was used to measure the level of thrombin-antithrombin complex (TATc), tumor necrosis factor-α (TNF-α) in bronchoalveolar lavage fluid (BALF), and lung wet/dry (W/D) weight ratio, histology score were recorded.
  
  
  RESULTS
  At 6 hours after LPS-induced lung injury, the levels of TATc and TNF-α, lung W/D weight ratio and histology score in 6 U/g and 12 U/g group were all lower than those of control group significantly (TATc: 0.959±0.681 μg/L, 1.165±0.854 μg/L vs. 2.141±0.791 μg/L, TNF-α: 4.449±5.054 ng/L, 9.096±4.099 ng/L vs. 18.184±3.869 ng/L, W/D weight ratio: 7.018±1.137, 7.367±0.349 vs. 8.472±0.614, histology score: 16.0±1.0, 16.5±1.5 vs. 19.6±0.4, P<0.05 or P<0.01). There was no significant difference in the comparisons between the subgroups of UFH in TATc level in BALF and lung histology score. For the TNF-αlevel in BALF, 18 U/g group evidently exceeded that of 6 U/g group (15.503±8.753 ng/L vs. 4.449±5.054 ng/L, P<0.01), and lung W/D weight ratio in 18 U/g group was also significantly higher comparing to 6 U/g (8.850±1.157 vs. 7.018±1.137, P<0.05) and 12 U/g group (8.850±1.157 vs. 7.367±0.349, P<0.05).
  
  
  CONCLUSIONS
  It was appropriate for the dose of nebulized UFH to be administered no more than 12 U/g in ALI treatment, which was enough to inhibit alveolar coagulant cascade, decrease early inflammatory response and alleviate lung tissue injury.
authors.affiliation: Department of Critical Care Medicine, Peking University, Beijing, China.
authors.forename: Zong-yu
authors.initials: ZY
authors.lastname: Wang
authors.forename: Sheng-nan
authors.initials: SN
authors.lastname: Wu
authors.forename: Xi
authors.initials: X
authors.lastname: Zhu
mesh_terms: D055371:Acute Lung Injury / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology*; D000280:Administration, Inhalation; D000818:Animals; D001777:Blood Coagulation / Q000187:drug effects; D004731:Endotoxins / Q000009:adverse effects; D006493:Heparin / Q000008:administration & dosage* / Q000494:pharmacology; D007249:Inflammation / Q000188:drug therapy; D008168:Lung / Q000503:physiopathology; D008297:Male; D011650:Pulmonary Alveoli / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar
chemical_list: D004731:Endotoxins; D006493:Heparin