Intravenous administration of activated protein C in Pseudomonas-induced lung injury: impact on lung fluid balance and the inflammatory response

• Published in: Respiratory research 2006-03, Vol.7 (1), p.41-41, Article 41
• Main Authors: Robriquet, Laurent, Collet, François, Tournoys, Antoine, Prangère, Thierry, Nevière, Rémi, Fourrier, François, Guery, Benoît P
• Format: Article
• Language: English
• Subjects: Animals; Antithrombin III - metabolism; Blood Coagulation - drug effects; Bronchoalveolar Lavage Fluid - chemistry; Bronchoalveolar Lavage Fluid - cytology; Bronchoalveolar Lavage Fluid - microbiology; Disease Models, Animal; Extravascular Lung Water - drug effects; Extravascular Lung Water - metabolism; Fibrin; Fibrinolytic Agents - administration & dosage; Fibrinolytic Agents - therapeutic use; Inflammation - metabolism; Inflammation - microbiology; Inflammation - pathology; Infusions, Intravenous; Interleukin-6 - metabolism; Lung - metabolism; Lung - microbiology; Lung - pathology; Lung diseases; Male; Neutrophils - drug effects; Neutrophils - pathology; Oxygen - metabolism; Peptide Hydrolases - metabolism; Permeability; Pneumonia, Bacterial - metabolism; Pneumonia, Bacterial - microbiology; Pneumonia, Bacterial - pathology; Protein C; Protein C - administration & dosage; Protein C - genetics; Protein C - pharmacology; Pseudomonas aeruginosa; Pseudomonas aeruginosa - isolation & purification; Rats; Rats, Sprague-Dawley; Recombinant Proteins - administration & dosage; Recombinant Proteins - pharmacology; Respiratory Distress Syndrome, Adult - metabolism; Respiratory Distress Syndrome, Adult - microbiology; Respiratory Distress Syndrome, Adult - pathology; Tumor Necrosis Factor-alpha - metabolism
• ISSN: 1465-993X; 1465-9921; 1465-993X; 1465-9921
• DOI: 10.1186/1465-9921-7-41

Acute lung injury (ALI) induces a coagulation/fibrinolysis imbalance and leads to fibrin deposition. The protein C pathway is an important regulator of the coagulation system and reduces the inflammatory response. The aim of the study was to examine the effects of recombinant human activated protein C (rhAPC) in the early phase of Pseudomonas aeruginosa (Pa)-induced lung injury. The study was conducted in vivo on a rat model of Pa-induced ALI. Continuous intravenous (IV) rhAPC was administrated simultaneously with intratracheal (IT) Pa. We instilled into the airspaces a 5% bovine albumin solution with 1 mu(Ci of (125)I-albumin and injected IV 1 mu(Ci of (111)In-albumin to measure lung liquid clearance (LLC) and endothelial injury. Cytokines levels (TNFalpha and IL-6) and thrombin-antithrombin (TAT) complexes were measured in blood and bronchoalveolar lavage fluid (BALF) at 4 hours. Four groups were compared: control (CTR), pneumonia (PNP) receiving IT Pa (0.5 ml/kg of 1 x 10(9) cfu), APC: IV rhAPC (300 microg/kg/h), A-PNP: IT Pa /IV rhAPC. Alveolar-capillary permeability was increased in the PNP versus the CTR group (0.28 +/- 0.08 vs. 0.03 +/- 0.01, p < 0.05). IV rhAPC in Pa-induced ALI led to further injury (0.47 +/- 0.17 vs. 0.28 +/- 0.08, p = 0.2). The LLC was significantly decreased in the A-PNP group compared to PNP group (9.1 +/- (4.3% vs. 33.4 +/- 2.6%, p < 0.05). The lung wet to dry weight ratio was significantly increased in the PNP group (4.62 +/- 0.31) compared to the CTR group (3.87 +/- 0.22, p < 0.05). IV rhAPC administration tends to increase this parameter in Pa-induced ALI (5.80 +/- 0.66, p = 0.07). These findings were associated with a loss of inflammatory response compartmentalization measured by TNFalpha and IL-6 systemic levels. TAT complexes in BALF were increased in the A-PNP group (23.17 +/- 2.89 ng/ml) compared to the CTR group (0.92 +/- 0.17 ng/ml, p < 0.05) and the PNP group (11.06 +/- 2.76 ng/ml, p < 0.05). rhAPC reduces LLC following Pa-induced ALI and may influence pulmonary edema formation. The early massive fibrin formation is probably beneficial in ALI limiting both the extent of injury and permeability disorders.