Elevated Concentration of Adenosine 3′:5′-cyclic Monophosphate in Intestinal Mucosa after Treatment with Cholera Toxin

A heat-labile factor in cell-free filtrate of a Vibrio cholerae culture induces a marked rise in the wet-weight concentration of adenosine 3′:5′-cyclic monophosphate (cyclic AMP) in the intestinal mucosa of the dog. The increase becomes appreciable 1-1.5 hr after intraluminal administration of the filtrate, about the same time as the onset of intestinal secretion in response to a heat-labile enterotoxin in the filtrate. These results are consistent with the hypothesis that cyclic AMP may be an intermediary in the intestinal secretory response to cholera toxin.