The effect of sham-feeding on gallbladder volume and circulation of bile acids.

Sham-feeding is believed to induce only a vagal stimulus. In the present investigation its effect on gallbladder volume and bile acid circulation was studied. In 8 out of 9 persons we observed a decrease in gallbladder volume from 20.1 +/- 2.4 ml to 15.4 +/- 2.2 ml. After 150 min, serum bile acids had increased from initially 2.0 +/- 0.3 mumoles/l to 2.3 +/- 0.4 mumoles/l. In 10 persons given a liquid test meal, there was a decrease in gallbladder volume from 18.3 +/- 2.7 ml to 5.2 +/- 0.7 ml. Bile acids rose from 2.6 +/- 0.3 mumoles/l to 4.1 +/- 0.5 mumoles/l after 90 min. The response after the test meal was thus more enhanced and faster. It is concluded that: 1. Vagal stimulation from the oral mucosa by sham-feeding can induce evacuation of the gallbladder and enterohepatic circulation of bile. 2. Under normal circumstances this mechanism is probably of minor importance.