Stimulation of Intestinal Secretion In Vitro by Culture Filtrates of Escherichia coli

Abstract

Cell-free supernatant fluid from cultures of a strain of Escherichia coli isolated from a patient with cholera-like diarrhea was tested in the intestine of rabbits. When ileal loops were exposed to supernates from E. coli cultures for 1 hr and then placed in a flux chamber, normal absorption of sodium was inhibited and secretion of chloride ion appeared as a new process. These changes were the same as those seen after exposure to cholera enterotoxin. It is known that the changes in ion flux caused by these toxins are identical with those produced by agents that increase intestinal levels of adenosine-3′:5′-monophosphate (cAMP). Cholera toxin stimulates production of adenyl cyclase and raises levels of cAMP. It is speculated that enterotoxin of E. coli acts by a similar mechanism.