Secretory pathways in Salmonella Typhimurium-induced fluid accumulation in the porcine small intestine

Abstract

The involvement of 5-hydroxytryptamine (5-HT) and 5-HT3 receptors and prostaglandin E2 (PGEz) in Salmonella Typhimurium-induced fluid accumulation in the porcine small intestine was investigated. Salmonella Typhimurium (10' and 10" cfu) and cholera toxin (CT; 20pg) were instilled for 8 and 11 h in ligated loops in the porcine jejunum and ileum. Fluid accumulation and concentrations of Na+, K f , C1-, 5-HT and PGE2 in the fluid accumulated in the loops were measured. The fluid accumulation was also measured when Salmonella Typhimurium (10'' cfu) and CT (20 pg) were instilled for 8 h in ligated loops in jejunum and ileum in pigs given subcutaneous injections of saline or the 5-HT3 receptor antagonist ondansetron (200 pg/kg). Salmonella Typhimurium (10" cfu) and CT both induced fluid accumulation in jejunum and ileum after 8 and 11 h. Both treatments also induced an increase in luminal release of 5-HT and PGE2. The accumulated fluid was iso-osmotic and hyperosmotic in CT-and Salmonella Typhimurium-treated loops, respectively. Ondansetron reduced the Typhimuriuminduced fluid accumulation in both jejunum and ileum by c. 40%, while it failed to reduce the response to CT. These results demonstrate that 5-HT and PGEz are released and 5-HT3 receptors activated in the secretory pathway of Typhimurium in the porcine small intestine.

Cellular Signaling Mechanisms Underlying Pharmacological Action of Bak Foong Pills on Gastrointestinal Secretion.

“…The effect of BFP may be explored to treat GI disorders such as constipation. [Japanese Journal of Physiology, 52, 129-134, 2002] may result in diarrhea [4][5][6] or constipation [7,8] with severe pathological consequences. Therefore Cl Ϫ channels are very likely to be the target for pharmacological intervention.…”

New Zealand White Rabbit as a Nonsurgical Experimental Model forSalmonella entericaGastroenteritis

“…Animal deaths in the 10 7 -CFU challenge group occurred after all rabbits challenged with 10 11 and 10 9 CFU had died, supporting the dose-response relationship between challenge and time of death. Twenty-five percent of animals challenged with 10 7 CFU of DT-9 developed severe watery diarrhea containing mucus and blood. At the height of their illness, animals lost from 16 to 30% of their initial body weights, a significant loss compared with the results from the controls (Fig.…”

“…Although these animals develop diarrhea, they may not be representative of conventional animals. Surgical models that measure fluid accumulation as an indication of diarrheal disease caused by S. enterica serotypes have been developed with large animal species (1,5,10,13), and several nonsurgical models for diarrheal disease have been developed with pigs (15,20), calves (18,19,21), ponies (16), and primates (12,17). However, these animals are not readily available in a standard animal facility, and therefore the usage of large numbers for in-depth studies is precluded.…”

“…The second dose of sodium bicarbonate was immediately followed by oral administration of 15 ml of bacterial culture at a concentration of 10 11 , 10 9 , 10 7 , 10 5 , or 10 3 CFU per animal. The control animals were challenged with 10 11 CFU of heat-killed salmonellae or with LB broth alone. To slow intestinal peristalsis, all animals were given an intraperitoneal injection of 2.0 ml of paregoric (2 mg/5 ml; National Logistics Services).…”

Real-Time Optical Antimicrobial Susceptibility Testing

“…The Gram-negative facultative aerobe Salmonella enterica serovar Typhimurium 3389-1 DT12 was isolated from a clinical case of salmonellosis in pigs and was kindly donated by D. L. Baggesen at the Technical University of Denmark, National Veterinary Institute (28). The common Grampositive pig gut bacterium Streptococcus alactolyticus (type strain DSM 20728; DSMZ, Braunschweig, Germany) was included as an anaerobe representative.…”