RESUMO
INTRODUCTION: The effects of cholinergic agents and vagal control on gall-bladder motility are well defined. Alpha adrenergic antagonists have been found in previous studies to have a prokinetic effect on gall-bladder motility in normal human patients. Their effects have not, however, been fully elucidated in patients with gall-stone disease. OBJECTIVE: Our aim was to determine the effects of alpha-antagonists and beta-antagonists on gall-bladder motility in human patients with gall-stone disease. METHODS: In this single-blind, three-way crossover study, a slow release formulation of 80 mg propranolol (beta-antagonist), and 25 mg indoramin (alpha-antagonist), and placebo were administered separately to 10 patients with gall-stone disease on three separate days 8 h before assessment of gall-bladder volumes by ultrasonography. Gall-bladder volumes were assessed in the fasting state and at 5 min intervals for 50 min after a standard proprietary enteral feed (Ensure 180 ml, Abbott). Differences between the placebo and postadrenergic antagonist scan volumes were tested using the Wilcoxon-signed rank test. RESULTS: There were no significant differences in the mean fasting gall-bladder volumes after receiving propranolol, indoramin and placebo (23.6+/-3.9, 22.3+/-4.3, 26.8+/-7.2 ml, mean+/-SEM, respectively). In the postprandial period, however, indoramin significantly enhanced postprandial gall-bladder emptying compared with placebo between 5 and 30 min (P<0.05) after which refilling commenced. There were no significant postprandial gall-bladder volume differences between propranolol and placebo. CONCLUSION: Indoramin, an alpha-adrenergic antagonist, acts as a prokinetic agent enhancing postprandial gall-bladder emptying in patients with gall-stone disease. This effect is similar to its effect on postprandial gall-bladder emptying in healthy individuals.