RESUMO
OBJECTIVE: To investigate the effects of co-exposure of LPS and heat on TNF-alpha expression in rat kidneys. METHODS: Male pathogen-free Wistar rats were randomly assigned in saline-injected normothermic control (C group), saline-injected heat exposure (H group), LPS-injected normothermic control (L group), and LPS-injected heat exposure (HL group). The rats in H and HL groups were exposed in a chamber at an ambient dry bulb temperature (Tdb) of 35.0-/+0.5 degrees, and those in C and L groups were exposed to a Tdb of 26-/+0.5 degrees. The rats in L and HL groups were given an intravenous injection of LPS (10 mg/kg) via the tail vein to induce endotoxemia, and equivalent normal saline was injected in C and H groups. TNF-alpha expression in the kidney was detected by immunohistochemical SABC method, and the renal damage was evaluated histologically at 120 min after the treatment. RESULTS: Co-exposure of the rats with LPS and heat caused significantly enhanced TNF-alpha expression and histopathological damage in the kidneys. CONCLUSION: LPS combined with heat exposure causes renal toxicity, while is closely associated with the expression of TNF-alpha in the kidneys.