Objective To investigate the effects of
propofol administered before, with or after lipopolysaccharide (LPS) on the acute
lung injury (ALI)
induced by IPS in rats. Methods Seventy-six male Wistar rats weighing 250-290 g were randomly divided into 5 groups : (A) control group received only normal saline (n = 8); (B) LPS group received LPS 8 mg·kg-1 iv (n = 17); (C, D, E) propofol group-Ⅰ,Ⅱ, Ⅲreceived propofol (a bolus of 5 mg·kg-1 followed by infusion at 10 mg·kg-1·h-1) 1 h before (group C, propofol - Ⅰ , n = 17) , simultaneously with (group D, propofol-Ⅱ, n=17) or 1h after LPS administration (group E, propofol-Ⅲ , n = 17) . The animals were observed for 5h after LPS administration for MAP monitoring and mortality and then killed. The lungs were immediately removed for determination of expressions of nitrotyrosine protein and iNOS mRNA, wet / dry lung weight ratio and pulmonary permeability index (PPI). The lungs were also lavaged. The bronchoalveolar lavage fluid (BALE) was collected for measurement of TNF-α, NO and protein contents. Results In group C and D propofol given before and simultaneously with LPS significantly inhibited the increase in nitrotyrosine protein and iNOS expression induced by LPS, improved MAP, reduced 5h mortality rate, decreased PPI and protein, NO and TNF-αcontents in BALF compared with group B (P < 0.01 or 0.05) . In group E the
protective effects of propofol was significantly weaker. Conclusion The study showed that propofol administered before LPS provides best protective effects on the lungs against acute injury induced by LPS.