Acute respiratory distress syndrome (ARDS) is a complex syndrome of intense pulmonary inflammatory response with high morbidity and mortality, and is characterized by neutrophil accumulation, interstitial edema, disruption of epithelial integrity, and leakage of protein into the alveolar space that are associated with severe alterations in gas exchange. 1) The mortality remains in the range of 30 to 70%, similar to that in seventies when the disease was first described despite of recent advances in intensive care. [2][3][4] The most common cause of ARDS is well known to be sepsis.
5,6)The precise pathogenesis for sepsis induced ARDS is not yet fully defined. However, massive accumulation of neutrophils in the lung and increased pulmonary pro-inflammatory cytokines such as tumor necrosis factor-alpha (TNF -α), interleukin (IL) -1β, IL-6, and IL-8 are major features of ARDS. These mediators have been suggested to play important roles in the initiation and progression of ARDS. [7][8][9][10] The activation of the neutrophils within the lung causes microvascular injury, attributed to the release of neutrophil proteases and reactive oxygen species (ROS). 11,12) Gabexate mesilate (Foy Ⓡ ), a synthetic protease inhibitor used as an anticoagulant, has been found the effective in the treatment of acute pancreatitis and disseminated intravascular coagulation (DIC) due to sepsis in human and in an animal model of sepsis. [13][14][15] This drug not only inhibits the function of thrombin, plasmin, kallikrein, trypsin, and neutrophil elastase but also suppresses the adhesion and activation of the neutrophil. 16,17) Ulinastatin, hydrolase inhibitor, suppress IL-8 release during one lung anesthesia in surgery. 18) And it also prevents platelet aggregations in patients with DIC or sepsis.
14)Thus, these effects of Foy Ⓡ may be advantageous in certain conditions such as acute lung injury due to sepsis.The major aim of this study was to evaluate whether theseBackground: This study was to clarify the effects of gabexate mesilate (Foy Ⓡ ), a synthetic protease inhibitor, on endotoxin induced acute lung injury in rabbit. Methods: Animals were randomly assigned to one of four groups: saline only (n = 7), saline and Escherichia coli endotoxin 5 mg/kg over 30 mins (n = 7), Foy Ⓡ 1 mg/kg bolus, followed by infusion of Foy Ⓡ at 1 mg/kg/h and endotoxin (n = 7), Foy Ⓡ 2 mg/kg bolus, followed by infusion of Foy Ⓡ at 2 mg/kg/h and endotoxin (n = 7). Infusion of saline or Foy Ⓡ was started 0.5 hour before the start of infusion of saline or endotoxin and continued for 6.5 hours. At the end infusion animals were sacrificed, and the wet to dry (W/D) weight ratio of lung, lung injury score and leukocyte counts, percentage of polymorphonuclear leukocyte (PMNL), and concentrations of albumin and interleukin-8 (IL-8) in bronchoalveolar lavage fluid (BALF) were evaluated.Results: Endotoxin decreased the PaO2 and peripheral blood leukocyte and platelet counts. And it increased the W/D weight ratio of lung, lung injury score and leukocyte counts, percenta...