title: Assessment of circulatory and pulmonary endothelin-1 levels in a lavage-induced surfactant-depleted lung injury rabbit model with repeated open endotracheal suctioning and hyperinflation.
abstract: OBJECTIVE
  Endothelin-1 (ET-1) is a mediator of various physiological and pathological processes, including vascular inflammation, cell proliferation and vasoconstriction. Attenuation of ET action using ET-1 antagonists reduces pulmonary vascular leakage and inflammation in several models of lung injuries and experimental acute respiratory distress syndrome (ARDS). Based on these earlier reports, the current study investigates the patterns of ET-1 levels in circulation and pulmonary tissues in an experimental model of lavage-induced surfactant-depleted lung injury. Additionally, we also test the effects of open endotracheal suctioning (OES) and hyperinflation (HI) as recruitment maneuver following OES on ET-1 levels.
  
  
  METHODS
  Briefly, 24 Japanese white rabbits were anesthetized and intubated. Normal saline was instilled into the lung and washed mildly. After instillation, rabbits were ventilated at definite settings at a total duration of 3 hours. OES and HI were performed every 15 minutes from the beginning of the protocol.
  
  
  RESULTS
  Here, we show that both circulatory and pulmonary ET-1 levels increased in models with lung injury induced by saline lavage compared to healthy control group. No further aggravation in expression of pulmonary ET-1 was seen after OES and HI, although OES and HI worsened arterial hypoxygenation and severity of lung injury. In contrast, circulatory ET-1 levels significantly decreased after OES and HI but were not associated with blood pressure changes.
  
  
  CONCLUSIONS
  We conclude that in a saline lavage-induced lung injury model, both circulatory and pulmonary ET-1 levels increased. Further, OES and HI exerted differential effects on ET-1 expression at both circulatory and pulmonary levels.
authors.affiliation: Department of Emergency and Critical Care Medicine, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Junko
authors.initials: J
authors.lastname: Kamiyama
authors.affiliation: Department of Emergency and Critical Care Medicine, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Subrina
authors.initials: S
authors.lastname: Jesmin
authors.affiliation: Department of Emergency and Critical Care Medicine, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Sakuramoto
authors.affiliation: Department of Emergency and Critical Care Medicine, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Nobutake
authors.initials: N
authors.lastname: Shimojo
authors.affiliation: Department of Emergency and Critical Care Medicine, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Md Majedul
authors.initials: MM
authors.lastname: Islam
authors.affiliation: Department of Emergency and Critical Care Medicine, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Tanzila
authors.initials: T
authors.lastname: Khatun
authors.affiliation: Department of Emergency and Critical Care Medicine, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Masami
authors.initials: M
authors.lastname: Oki
authors.affiliation: Department of Emergency and Critical Care Medicine, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Satoru
authors.initials: S
authors.lastname: Kawano
authors.affiliation: Department of Emergency and Critical Care Medicine, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan. Electronic address: mizutani@md.tsukuba.ac.jp.
authors.forename: Taro
authors.initials: T
authors.lastname: Mizutani
mesh_terms: D000818:Animals; D001784:Blood Gas Analysis; D001992:Bronchoalveolar Lavage Fluid; D004195:Disease Models, Animal; D019332:Endothelin-1 / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D006439:Hemodynamics; D055370:Lung Injury / Q000097:blood* / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D011659:Pulmonary Gas Exchange; D011663:Pulmonary Surfactants / Q000378:metabolism*; D011817:Rabbits; D044023:Receptor, Endothelin B / Q000378:metabolism; D015656:Respiratory Mechanics; D013396:Suction / Q000379:methods*; D007507:Therapeutic Irrigation / Q000379:methods*; D014132:Trachea / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*
chemical_list: D019332:Endothelin-1; D011663:Pulmonary Surfactants; D044023:Receptor, Endothelin B
keywords: Arterial oxygenation; Endothelin-1; Hyperinflation; Lung injury; Open endotracheal suctioning