Acute pulmonary injury induced by experimental muscle trauma.

Abstract

PURPOSE: To develop an easily reproducible model of acute lung injury due to experimental muscle trauma in healthy rats. METHODS: Eighteen adult Wistar rats were randomized in 3 groups (n=6): G-1- control, G-2 - saline+trauma and G-3 - dexamethasone+trauma. Groups G-1 and G-2 were treated with saline 2,0 ml i.p; G-3 rats were treated with dexamethasone (DE) (2 mg/kg body weight i.p.). Saline and DE were applied 2h before trauma and 12h later. Trauma was induced in G-2 and G-3 anesthetized (tribromoethanol 97% 100 ml/kg i.p.) rats by sharp section of anterior thigh muscles just above the knee, preserving major vessels and nerves. Tissue samples (lung) were collected for myeloperoxidase (MPO) assay and histopathological evaluation. RESULTS: Twenty-four hours after muscle injury there was a significant increase in lung neutrophil infiltration, myeloperoxidase activity and edema, all reversed by dexamethasone in G-3. CONCLUSION: Trauma by severance of thigh muscles in healthy rats is a simple and efficient model to induce distant lung lesions.