Effect of shigella enterotoxin 1 (ShET1) on rabbit intestine in vitro and in vivo. Issue 4 (April 1997)

• Record Type: Journal Article
• Authors: Fasano, A; Noriega, F R; Liao, F M; Wang, W; Levine, M M
• Is Part Of: Gut. Volume 40:Issue 4(1997)
• Page Start: 505
• Page End: 511
• Publication Date: 1997-04
• Subjects: Gastroenterology -- Periodicals; 616.33
• DOI: 10.1136/gut.40.4.505
• Languages: English
• ISSNs: 0017-5749

Abstract

Abstract : 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.