Effects of somatostatin analogues on human sphincter of Oddi pressure

Somatostatin, a neuropeptide and hormone, exists in the biliary tract of several species. The effects of somatostatin and its analogues on the sphincter of Oddi motility have been controversial. The aim of this study was to observe the action of stilamin and sandostatin on the sphincter of Oddi via choledochofiberscope manometry.

Twenty patients who had had "T" duct after cholecystectomy and choledochotomy were divided into 2 groups randomly: stilamin and sandostatin. They were subjected to manometry via a choledochofiberscope through the "T" duct tract. The following data recorded included duodenal pressure (DP), sphincter of Oddi basal pressure (SOBP), sphincter of Oddi contractive amplitude (SOCA), frequency of the sphincter of Oddi (SOF), duration of the sphincter of Oddi, and the common bile duct pressure (CBDP).

After intravenous administration of stilamin at a dose of 250 microg/h, the mean SOCA increased from 89.18(26.50) to 128.57(54.21) mmHg (P<0.05). After the administration of stilamin at a dose of 500 microg/h the mean SOCA declined to 92.18(42.81) mmHg (P<0.05), and mean SOBP declined from 17.63(13.36) to 8.16(4.01) mmHg (P<0.05). Although SOF had declined from 9.25(2.45) to 7.46(1.52) n/min, it was not significantly influenced. After intravenous administration of sandostatin at a dose of 100 microg, the mean CBDP increased obviously.

Intravenous administration of stilamin at a dose of 250 microg/h stimulates the motility of the sphincter of Oddi whereas the injection of stilamin at a dose of 500 microg/h inhibits its motility. Intravenous injection of sandostatin of 100 mug has no effect on the sphincter of Oddi.