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Updated: May 5, 2026
Catheterization of Intestinal Loops in Ruminants
Published on: June 11, 2009
Effect of shigella enterotoxin 1 (ShET1) on rabbit intestine in vitro and in vivo
A Fasano1, F R Noriega, F M Liao
1Division of Pediatric, Gastroenterology and Nutrition, University of Maryland, School of Medicine, Baltimore 21201, USA.
Background:
Shigella enterotoxin 1 is a novel enterotoxin elaborated by Shigella flexneri 2a that causes fluid accumulation in rabbit ileal loops and a rise in short circuit current in Ussing chambers.
Aims:
To gain insights into the mechanism of action of shigella enterotoxin 1.
Methods:
Supernatants from genetically engineered clones either overexpressing shigella enterotoxin 1 or producing deletion mutants of the toxin were tested in rabbit ileum both in vitro and in vivo.
Results:
In rabbit ileum shigella enterotoxin 1 induced an irreversible rise in short circuit current that was not mediated by any of the recognised intracellular mediators of secretion. Deletion of 90% of the A subunit of the holotoxin ablated its enterotoxicity. In the in vivo perfusion model, the toxin induced a time dependent decrease in water absorption, whereas no changes were detected in the segment perfused with supernatants obtained from the deletion mutant. Finally, partially purified toxin induced a dose dependent increment in short circuit current that reached its plateau at a toxin concentration of 4 x 10(-6) M.
Conclusions:
Shigella enterotoxin 1 induces a time and dose dependent intestinal secretion in the rabbit animal model, suggesting that it may be responsible for the watery phase of Shigella flexneri 2a infection.
