Stimulation of Adenyl Cyclase by <Emphasis Type="Italic">Escherichia coli</Emphasis> Enterotoxin

THE acute diarrhoea of cholera is caused by an enterotoxin produced by Vibrio cholerae¹. Experimentally, the activity of this enterotoxin can be demonstrated in the ligated ileal loop of rabbits and dogs^2–4. In response to intraluminal application of cholera enterotoxin, these loops demonstrate net secretion of fluid and electrolytes⁵. V. cholerae, however, is not the only enteropathogen associated with acute diarrhoea. Certain strains of Escherichia coli, an organism usually considered to be normal bowel flora, have been associated with epidemics of acute diarrhoea in infants⁶, adults⁷ and a variety of animal species⁸. Like cholera, E. coli diarrhoea is the result of accidental introduction and colonization of the small intestine by an offending organism capable of producing an enterotoxin⁷.