Protective effects of early treatment with propofol on endotoxin-induced acute lung injury in rats

Background. To investigate the effects of propofol administration on acute lung injury in endotoxin-induced shock in rats. Methods. Seventy-six male Wistar rats were randomly assigned to one of five groups: (i) saline control; (ii) endotoxin alone (receiving lipopolysaccharide (LPS) 8 mg kg(-1) i.v.); (iii) pretreatment with propofol 1 h before LPS; (iv) simultaneous treatment with propofol and LPS; (v) post-treatment with propofol 1 h after LIPS. During the 5 h after LPS injection, survival rates were recorded. Lung tissue was sampled to measure values of nitrite/nitrates (NO2-/NO3-) and tumour necrosis factor (TNF)-alpha in bronchoalveolar lavage (BAL) fluid, and wet-to-dry lung weight ratio, pulmonary permeability index, BAL protein and expression of inducible nitric oxide synthase (iNOS) and nitrotyrosine (NT). Results. Compared with the endotoxaemic group, both the pre- and simultaneous treatment groups showed significantly improved 5 h survival rates, and attenuated endotoxin-induced increased BAL fluid NO2-/NO3- and TNF-alpha, iNOS mRNA and NT expression in lung tissue, and decreased pulmonary microvascular permeability. These beneficial effects were blunted in the post-treatment group. Conclusions. These findings indicate that early administration of propofol may provide protective effects against endotoxin-induced acute lung injury.