Acute pulmonary injury induced by experimental muscle trauma

Abstract

To develop an easily reproducible model of acute lung injury due to experimental muscle trauma in healthy rats. 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. 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. Trauma by severance of thigh muscles in healthy rats is a simple and efficient model to induce distant lung lesions.