Evidence for a nonneural electrogenic effect of cholera toxin on human isolated ileal mucosa.
Cholera toxin-induced intestinal secretion in intact rats requires a functioning myenteric plexus. The aim of this investigation was to determine whether neural elements were essential for cholera toxin to produce a secretory effect in human isolated ileum. Mucosal preparations were mounted in Ussing chambers. Cholera toxin was applied apically and short-circuit current monitored for 3 hr, at which point forskolin was given. Cholera toxin (10 microg/ml) induced a tetrodotoxin-insensitive increase in short-circuit current in muscle-stripped preparations of human ileum. The increase was not additive with the action of forskolin (25 microM). Cholera toxin exerts a marked nonneural secretory effect in human ileal mucosa in vitro, probably by the same mechanism as forskolin, namely elevation of cyclic AMP.
Burleigh
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DE
Department of Pharmacology, Queen Mary and Westfield College, London, U.K.
Borman
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RA
D001693:Biological Transport, Active / Q000187:drug effects; D002772:Cholera Toxin / Q000494:pharmacology*; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism; D006801:Humans; D007082:Ileum / Q000187:drug effects* / Q000294:innervation; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000187:drug effects* / Q000294:innervation
D005576:Colforsin; D002772:Cholera Toxin; D000242:Cyclic AMP