We have investigated the influence of prostaglandins (PGs) on the Salmonella typhimurium (St) and cholera toxin (CT)-induced fluid accumulation in jejunum of 9-10 weeks (18-20 kg) old female pigs. St (1010 colony forming units) and CT (56/ig) were instilled in separated tiedoff loops for 8 hours. Before instillation, and again after 4 hours, pigs were given an intravenous dose of the cyclooxygenase and prostaglandin synthesis inhibitor, indomethacin, or saline alone (control). In the St-loops indomethacin had no effect on the fluid accumulation, 9.1 ± 1.3 vs 8.2±0.5 mg fluid/mg loop dry weight, whereas in CT-Ioops, indomethacin reduced fluid accumulation significantly from 35±2 to 22±3 mg fluid/mg loop dry weight (P<0.05). Our preliminary results indicate that PGs are not involved in St-induced fluid accumulation in pig jejunum, which is in contrast to the case in CT -induced fluid accumulation.