PT  - JOURNAL ARTICLE
AU  - A Fasano
AU  - F R Noriega
AU  - F M Liao
AU  - W Wang
AU  - M M Levine
TI  - Effect of shigella enterotoxin 1 (ShET1) on rabbit intestine in vitro and in vivo.
AID  - 10.1136/gut.40.4.505
DP  - 1997 Apr 01
TA  - Gut
PG  - 505--511
VI  - 40
IP  - 4
4099  - http://gut.bmj.com/content/40/4/505.short
4100  - http://gut.bmj.com/content/40/4/505.full
SO  - Gut1997 Apr 01; 40
AB  - 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.