title: Surfactant protein D is a useful biomarker for monitoring acute lung injury in rats.
abstract: The purpose of this study is to investigate the serial changes in the SP-D concentrations of serum and bronchoalveolar lavage fluid (BALF) in a bleomycin-induced lung injury rat model and compare them with the levels of conventional biochemical markers.
  
  
  
  Male Wister rats were anesthetized and intratracheally administered bleomycin (1.0 mg/kg). We evaluated the histological changes and SP-D expression of their lung tissues. We also measured the concentrations of SP-D, albumin, and lactate dehydrogenase (LDH) and the numbers of various types of cells in BALF, and the serum levels of SP-D and conventional markers, including LDH, high mobility group box 1, monocyte chemoattractant protein-1, and C-reactive protein.
  
  
  
  The BALF SP-D level increased and peaked on day 3, and then gradually decreased. These variations were significantly correlated with the changes in the BALF albumin level and granulocyte cell count. The serum SP-D level increased from day 5, peaked on day 10, and then gradually decreased until day 28. The changes in the serum SP-D level accurately reflected the extent of the histological changes caused by the lung injury. On the other hand, the serum levels of conventional biomarkers were only elevated for a few days or did not change during the study period.
  
  
  
  The SP-D level is the most useful marker of the severity of lung injuries. These results suggest that the measurement of SP-D levels is an additional tool for monitoring acute lung injuries in rats.
authors.affiliation: a Research and Development Section , Diagnostics Department, Yamasa Corporation , Choshi , Chiba , Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Murata
authors.affiliation: b Department of Respiratory Medicine and Allergology , Sapporo Medical University School of Medicine , Chuo-ku , Sapporo , Japan.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Otsuka
authors.affiliation: a Research and Development Section , Diagnostics Department, Yamasa Corporation , Choshi , Chiba , Japan.
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Ashida
authors.affiliation: b Department of Respiratory Medicine and Allergology , Sapporo Medical University School of Medicine , Chuo-ku , Sapporo , Japan.
authors.forename: Gen
authors.initials: G
authors.lastname: Yamada
authors.affiliation: b Department of Respiratory Medicine and Allergology , Sapporo Medical University School of Medicine , Chuo-ku , Sapporo , Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Kuronuma
authors.affiliation: b Department of Respiratory Medicine and Allergology , Sapporo Medical University School of Medicine , Chuo-ku , Sapporo , Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Chiba
authors.affiliation: b Department of Respiratory Medicine and Allergology , Sapporo Medical University School of Medicine , Chuo-ku , Sapporo , Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Takahashi
mesh_terms: D055371:Acute Lung Injury / Q000097:blood* / Q000473:pathology; D000418:Albumins / Q000032:analysis; D000818:Animals; D015415:Biomarkers / Q000097:blood; D001761:Bleomycin; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry / Q000166:cytology; D045022:Lactate Dehydrogenases / Q000032:analysis; D007958:Leukocyte Count; D008168:Lung / Q000473:pathology; D008297:Male; D009929:Organ Size; D037663:Pulmonary Surfactant-Associated Protein D / Q000097:blood*; D017208:Rats, Wistar
chemical_list: D000418:Albumins; D015415:Biomarkers; D037663:Pulmonary Surfactant-Associated Protein D; D001761:Bleomycin; D045022:Lactate Dehydrogenases
keywords: biomarker; bleomycin; drug-induced lung injury; surfactant protein D