RESUMEN
BACKGROUND/AIMS: At present, the gallbladder dysfunction implies a disorder of decreased gallbladder contractility. Other motor disorder such as overactive gallbladder which shows excessive contraction cannot be excluded in the motility disorder of gallbladder. Thus, this study was done to define the diagnostic criteria and to develop the techniques to induce the excessive contraction of gallbladder. METHODS: CCK-op at 20 ng/kg by slow continuous infusion for 30minutes, that is known as most physiologic method for gallbladder contraction, was given for assessment of gallbladder emptying in 12 normal volunteers. Also, rapid bolus injection of cholecystokinin octapeptide (CCK-op) at 20 ng/kg or 40 ng/kg was performed to induce the excessive contraction of gallbladder. Gallbladder contractility was represented as the ejection fraction (GBEF) measured by cholecystokinin-cholescintigraphy. RESULTS: 1. With a slow continuous infusion of CCK-op, the mean GBEF was 78.2+/-5.6% (mean+/-SD). 2. With a rapid bolus injection of CCK-op, GBEF showed variable results (10-86%) among subjects who had normal gallbladder. 3. Based on the results obtained by slow continuous infusion of CCK-op in normal volunteers, overactive gallbladder was defined when GBEF approached more than 70% within 15minutes after bolus injection of CCK-op. The overactive gallbladder was noted in 6 (50%) subjects who received rapid bolus injection of CCK-op (40 ng/kg). 4. Abdominal pain developed only in high-dose (40 ng/kg) bolus injection group (6/12, 50%), concomitantly with increased bowel movements, irrespective of excessive gallbladder contractility. CONCLUSION: Excessive gallbladder contraction had no clinical significance in the experimentally induced clinical model.