Effects of cholecystectomy on the changes of motility of Beagle dogs' sphincter of Oddi

PURPOSE: To observe the effect of cholecystectomy on the changes of motion pattern of Beagle dogs' sphincter of Oddi (SO), and investigate the modulatory role of nitric oxide (NO) and cholecystokinin (CCK) in the regulation of SO. METHODS: Pressure of common bile duct, SO motility, response to bolus injections of cholecystokinin (CCK, 20 ng/kg and 100 ng/kg), basal pressure (BP) and phasic contraction amplitude (PCA) were measured respectively by manometry in six Beagle dogs before and after cholecystectomy. RESULTS: After cholecystectomy, the pressure and diameter of common bile ducts (CBD) was significantly increased (p < 0.01); BP and phasic contraction frequency (PCF) were also increased, however, no significant differences were found between the two groups; the SO motilities was not significantly changed. The relaxation responded to physiological dose of CCK (20ng/kg) was decreased, while bolus-dose of CCK (100ng/kg) induced rapid contractions and decreased PCA after cholecystectomy. The regulation pattern of SO pressure modulated by NO and its inhibitor had changed after cholecystectomy. CONCLUSION: After cholecystectomy in Beagle dogs, no obviously change of motion pattern of SO was observed through selfcompensation, but these compensations may lead to some changes of regulation pattern of CCK and NO on SO.