The inhibition of tumor necrosis factor alpha (TNF-alpha) production due to pre-treatment with steroidal (dexamethazone) and non-steroidal (sodium diclofenac) anti-inflammatories was studied in horses under experimentally induced endotoxemy. Fifteen stallions were allotted into three groups of five animals each: control (C), sodium diclofenac (SD) and dexamethazone (DM). Sublethal endotoxemy was induced with 0.1mg/kg/bw Escherichia coli 055:B5 lipopolysaccharide (LPS), IV, administrated in 250ml of 0.9% sterile sodium chloride, during 15 minutes. Control group horses received 9% sodium chloride, IV. SD group animals were orally administrated 2.2mg/kg sodium diclofenac and DM horses received 1.1mg/kg dexamethazone, IV, 30 and 60 minutes before endotoxin infusion, respectively. TNF-alpha concentration was measured in serum and peritoneal fluid by toxicity assay using L929 lineage cells at 0, 1¼, 3 and 6 hours after LPS injection. Ninety minutes after endotoxemy induction, it was verified a significant increase of serum TNF-a concentration in horses from control group in relation to the basal values as well as results of horses from SD and DM groups. In peritoneal fluid, the measured concentrations were lower than those from TNF-a standard curve and difference among the groups was not verified (P>0.05).
cytocin; dexamethazone; sodium diclofenac; endotoxin
