Acute administration of RC-3095 decreased TLR4 mRNA expression, TLR4 and nuclear content of p65 level in lung in rats subject to lethal sepsis. Male Wistar rats were subjected to CLP and were divided (n = 5 per group) into sham-operated, CLP and CLP plus RC-3095 groups. RC-3095 (3 mg/kg subcutaneously) was administered immediately after surgery. Six hours after surgery, BALF was collected and lung tissue was removed. (A) RT-PCR experiments showed that TLR-4 mRNA levels (reported as TLR-4 mRNA/GPDH) were increased in CLP rats (*p < 0.05 versus sham), and this was reversed in CLP rats treated with RC-3095 ($p < 0.05 versus CLP). (B–D) Immunoblot experiments showed that CLP produced increased TLR-4 and nuclear content of p65 protein levels in lung tissue extracts (*p < 0.05 versus sham) and that RC-3095 treatment decreased this increase ($p < 0.05 versus CLP) but did not show significant differences in MyD88. Scanning densitometry results are expressed as arbitrary units. Bars represent means ± SD of five rats. IB, immunoblot.