Effects of betazole hydrochloride and cimetidine on common bile pressure and duodenal myoelectric activity in the dog.

Betazole hydrochloride, a histamine analogue that stimulates the H2 receptor, causes an immediate and significant increase in common bile duct pressure. This pressure elevation correlates with an increase in duodenal myoelectric activity. Both the duodenal myoelectric activity and common bile duct pressure immediately returned to near baseline following the administration of cimetidine, an H2 blocker.