Factors affecting gallbladder motility in sheep

1. Intravenous injections of cholecystokinin, pentagastrin and pilocarpine nitrate into conscious sheep stimulated gallbladder contractions. Cholecystokinin increased gallbladder pressure up to 11 ± 2.8 mm Hg for 40 ± 4.9 min (4 animals). The responses to pentagastrin and pilocarpine were similar in magnitude but shorter in duration than those to cholecystokinin. 2. Electrical stimulation of the vagus nerves caused gallbladder contraction in anaesthetized sheep. 3. Secretin stimulated gallbladder contraction but the responses were not consistent. 4. The relative molar potency of cholecystokinin: pentagastrin on isolated gallbladder strips was 1:810. 5. It was concluded that cholecystokinin, gastrin and the vagus nerves may each be involved in the control of gallbladder motility in sheep