Electroacupuncture may relax the sphincter of Oddi in humans

Background: This study was designed to evaluate the effects of electroacupu ncture on sphincter of Oddi (SO) motility in humans and to associate the ma nometric findings with cholecystokinin (CCK) plasma levels. Methods: Eleven patients (M:F = 5:6) with various kinds of biliary disorder s were enrolled. SO motility was monitored with conventional low-compliance , continuous perfusion technique at ERCP (n = 9) or via percutaneous transh epatic cholangioscopy (n = 2), After baseline monitoring for phasic wave co ntractions of SO, electroacupuncture was applied at a specific acupoint GB 34. A nonspecific acupoint 5 cm away from GB 34 was selected as a control. Manometric parameters of the SO were also measured in 6 subjects during sti mulation of the control acupoint. CCK plasma levels were measured during el ectroacupuncture stimulation. Results: All manometric parameters including basal pressure, amplitude, fre quency, and duration of phasic wave contractions of the SO were significant ly decreased (p < 0.05) during electroacupuncture stimulation. The inhibiti on of SO contractility was accompanied by increased CCK plasma levels. Afte r discontinuation of electroacupuncture stimulation, restoration of amplitu de and duration to basal conditions was noted. A tendency toward return of SO basal pressure and contractile frequency to baseline was also observed. Stimulation of the control acupoint did not affect SO contractility. Conclusion: Electroacupuncture stimulation of acupoint GB 34 resulted in re versible inhibition of SO contraction in humans. The response of SO to elec troacupuncture stimulation may be mediated by some neurohormonal mechanisms including CCK release.