The effects of caerulein and a meal stimulus on gallbladder intraluminal pressure and bile flow in the pig

The intraluminal gallbladder pressure has been measured in a conscious unsedated pig model by the use of a radiotelemetry pressure capsule. A loop fistula was incorporated to measure bile output simultaneously. Mean fasting intraluminal gallbladder pressure was found to be 15±4 mmHg above atmospheric pressure, and mean fasting bile output 7·5±0·8 ml/10 min. Following intravenous caerulein pressure peaked at 2 min with a mean rise of 17±3 mmHg above basal (P<0·005). Bile output was increased for 30 min following caerulein with a total mean increase for this period of 13·5±2·2 ml (P<0·005). Gallbladder pressure rose significantly 5 min after commencing a meal by 6·0±1·9 mmHg (P<0·025) reaching a peak pressure 65 min after the meal with a mean rise of 14·8±2·3 mmHg (P<0·005). Bile output was significantly increased for 50 min following the ingestion of food. The total increments above basal values for bile output being 15·9±2·7 ml (P<0·005) in the first 30 min post‐randially and 11·6±2·4 ml (P<0·005) in the 30—60 min period. This model re‐emphasizes the rapidity of the hormonal response and may be valuable for further studies on the physiology of post‐randial gallbladder emptying.