[Effect of somatostatin on the rabbit Oddi's sphincter in vivo. Interrelation of somatostatin and cholecystokinin].

The action of somatostatin on the myoelectrical activity of the sphincter of Oddi was studied in anesthetized rabbits equipped with bipolar electrodes. The activity of the sphincter was recorded at the basal state and during 30 min after injection of somatostatin. After a bolus injection of somatostatin (1 to 8 micrograms/kg), the myoelectrical activity of the sphincter of Oddi decreased between the 2nd and the 10th min with a parallel decrease of the biliary pressure. These modifications were significant at the doses of 4 and 8 micrograms/kg only. There was a good dose-effect relationship. Moreover, the infusion of somatostatin (60 micrograms/kg/h) led to a decrease in sphincter activity. Bolus injection of cholecystokinin (2 UD/kg) under somatostatin infusion (60 micrograms/kg/h) induced an increase in the activity of the sphincter of Oddi. However, this activity never returned to basal levels.