Effects of intraportal prostacyclin on hepatic bile flow in the rat

Prostaglandins including prostacyclin (PGI2) have been demonstrated to have choleretic properties in dogs and in this study the effect of PGI2 on bile flow in rats has been investigated. PGI2 at a dose of 250 ng kg-1 min-1 was infused into the mesenteric vein of biliary cannulated rats and bile samples were collected every 10 min. Administration of PGI2 did not produce any significant changes in bile flow and in the output of bile acids or sodium, potassium and bicarbonate as compared to controls infused with buffer alone. Similarly no differences in pancreatic juice flow or bicarbonate output were observed between PGI2 treated rats and controls. No hypotension was observed at this dose of PGI2 given intraportally indicating inactivation by the liver. Thus in the rat, unlike the dog, no effects of PGI2 on bile flow were observed but this could be related to the route of administration.