The effect of prostacyclin on intestinal ion transport in the rat

The actions of PGI₂ and PGE₂ on electrically monitored ion transport in rat jejunum and colon have been determined both $\text{in vivo}$ and $\text{in vitro}$. Whilst PGE₂ was shown to induce a marked change in ion transport PGI₂ was relatively ineffective. The ability of the prostanoids to influence ion transport is related to their capacity to change mucosal cyclic AMP levels since in isolated small intestinal enterocytes PGE₂ caused a marked stimulation in cyclic AMP levels whilst PGI₂ had little effect. In colonic mucosal scrapes PGE₂ was more effective than PGI₂ in stimulating changes in cyclic AMP levels. It appears doubtful that PGI₂ plays a direct role in the regulation of intestinal ion transport.