Although urethane at higher concentration (>1.1 g/kg, ip) exhibited anti-inflammatory effects and protected rats against lethal endotoxemia with reduced TNF-α release, urethane at lower concentrations (0.1 and 0.5 g/kg, ip) [25] did not show significant protection or prevent death from LPS challenge. Here, TNF is linked to serum lipopolysaccharide activity.