Role of prostaglandins and cAMP in the secretory effects of cholera toxin.

The role of adenosine 3',5'-monophosphate (cAMP) and prostaglandins in the pathogenesis of experimental cholera was evaluated. Fluid accumulated in the rabbit intestinal loop model after 16 hours of incubation with cholera toxin, prostaglandin E1, or prostaglandin E2, but not with membrane-permeable derivatives of cAMP or forskolin. Dibutyryl cAMP triggered a small, transient intestinal fluid accumulation response by 4.5 hours; however, the fluid was completely absorbed by 9 hours. After exposure of intestinal loops to cholera toxin, prostaglandin E was released into the intestinal lumen in a concentration-dependent manner independent of cAMP. Thus, not only cAMP, but also prostaglandins may regulate water and electrolyte secretion in cholera.