title: A hemolysin of Vibrio mimicus (VMH) stimulates cells to produce ATP and cyclic AMP which appear to be secretory mediators.
abstract: The hemolysin of Vibrio mimicus(VMH) is a pore-forming toxin with both enterotoxic and hemolytic activity. The hemolysis by VMH is induced by creation of pores in the membrane of erythrocyte; however, the mechanism for the enterotoxic action of VMH has remained unclear. In order to clarify the mechanism, we incubated T84 cells (a human colon carcinoma cell line) with VMH and found that the levels of ATP and cyclic AMP of culture medium increased after exposure of the cells to VMH. Subsequently, we found that the fluid accumulating activity of VMH in a mouse internal loop assay was reduced by administration of glibenclamide, an inhibitor of cyclic AMP-dependent chloride channels, into the intestinal loop. These results suggest that the stimulation of cells to produce nucleotides by VMH is linked to the enterotoxic activity of the toxin.
authors.affiliation: Faculty of Pharmaceutical Sciences, Okayama University, Okayama, Okayama, Japan.
authors.forename: Yunshan
authors.initials: Y
authors.lastname: Li
authors.forename: Keinosuke
authors.initials: K
authors.lastname: Okamoto
authors.forename: Eizo
authors.initials: E
authors.lastname: Takahashi
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Miyoshi
authors.forename: Sumio
authors.initials: S
authors.lastname: Shinoda
authors.forename: Takao
authors.initials: T
authors.lastname: Tsuji
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Fujii
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D001426:Bacterial Proteins; D001826:Body Fluids / Q000378:metabolism; D045744:Cell Line, Tumor; D018118:Chloride Channels / Q000037:antagonists & inhibitors; D000242:Cyclic AMP / Q000378:metabolism*; D004768:Enterotoxins / Q000633:toxicity*; D005905:Glyburide / Q000494:pharmacology; D006460:Hemolysin Proteins / Q000502:physiology* / Q000633:toxicity*; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D044164:Vibrio mimicus / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D018118:Chloride Channels; D004768:Enterotoxins; D006460:Hemolysin Proteins; C073845:hemolysin, Vibrio; D000255:Adenosine Triphosphate; D000242:Cyclic AMP; D005905:Glyburide