Assessment of Lung Inflammation in a Mouse Model of Smoke Inhalation and Burn Injury

Abstract

Introduction To test concepts developed in our ovine model of ARDS, methods for quantitative assessment of acute inflammation in the lung were applied to our murine model of smoke inhalation and burn (S+B) injury. Methods Mice received S+B injury per protocol, n = 5 to 8 per group. Mice were anesthetized, intubated and exposed to cooled cotton smoke (4X 30 sec for Balb/C, 2X 30 sec for C57). After s.q. injection of 1 ml 0.9% saline, they received a 40% total body surface area (TBSA) burn. Buprenorphene (2 mg/kg) was given i.p. for analgesia. 0.9% saline was given i.p. at 4 ml/kg per %TBSA burn. Evans Blue dye (EB) was injected i.v. 15 min before sacrifice. Lung wet/dry weight ratio was measured. After vascular perfusion, lungs were sampled for myeloperoxidase (MPO), using an EIA kit, and content of EB dye. Results There was a significant (* = p < 0.05) increase in EB dye content, wet/dry weight ratio and MPO 24 h after injury in Balb/C mice. Similar increases were seen in C57 mice 48 h after S+B injury, but not at 24 h. Conclusions C57 mice tolerated less smoke inhalation than Balb/C mice, and required 48 hr to show significant increases in these variables. The mouse model can be used effectively to assess acute inflammation in the lung. Supported by Shriners of North America and National Institutes of Health