Sonographic Measurement of Gallbladder Volume in Healthy Volunteers after Sublingual Nifedipine

Abstract

The effect of nifedipine on gallbladder volume was studied sonographically among eleven healthy volunteers. Gallbladder volumes were recorded in the fasting state, 45 minutes after fatty meal and 5,10,15,30,60 and 120 minutes thereafter. The procedure was repeated on another day with the addition of nifedipine 10 mg sublingually (SI) after recording the first postprandial volume. Nifedipine increased gallbladder volume in 10 minutes from 5.4±1.3ml to 8.0±1.9ml (P＜0.05). Maximum increment was observed in 30 minutes from 4.1±0.7 to 9.3±2.4ml (P＜0.01). In 60 minutes nifedipine showed an inhibitory effect on gallbladder relaxation, which persisted another 60 minutes. ”Rebound” phenomenon, increased sensitivity of gallbladder smooth muscles to endogenous cholecystokinin (CCK) and interactions of hormones had been postulated as possible factors for this inhibitory effect. Throughout the study there was no significant change in the diameter of main bile duct. In summary, nifedipine increases gallbladder volume by relaxation and inhibition of contractive forces. The maximum effect is observed in 30 minutes. In 120 minutes the gallbladder remains contracted by opposing the spontaneous gallbladder relaxation. The combined effect of fatty meal and nifedipine can be used as a functional test of gallbladder among Chinese people.