The cholecystokinin-1 receptor antagonist devazepide increases cholesterol cholelithogenesis in mice

Background: A defect in gallbladder contraction function plays a key role in the pathogenesis of gallstones. The cholecystokinin-1 receptor (CCK-1R) antagonists have been extensively investigated for their therapeutic effects on gastrointestinal and metabolic diseases in animal studies and clinical trials. However, it is still unknown whether they have a potential effect on gallstone formation.

Design: To study whether the CCK-1R antagonists enhance cholelithogenesis, we investigated Cholesterol crystallization, gallstone formation, hepatic lipid secretion, gallbladder emptying function and intestinal Cholesterol absorption in male C57BL/6J mice treated by gavage with devazepide (4 mg/day/kg) or vehicle (as controls) twice per day and fed the lithogenic diet for 21 days.

Results: During 21 days of feeding, oral administration of devazepide significantly accelerated Cholesterol crystallization and crystal growth to microlithiasis, with 40% of mice forming gallstones, whereas only agglomerated Cholesterol monohydrate crystals were found in mice receiving vehicle. Compared to the vehicle group, fasting and postprandial residual gallbladder volumes in response to the high-fat meal were significantly larger in the devazepide group during cholelithogenesis, showing reduced gallbladder emptying and bile stasis. Moreover, devazepide significantly increased hepatic secretion of biliary Cholesterol, but not Phospholipids or bile salts. The percentage of intestinal Cholesterol absorption was higher in devazepide-treated mice, increasing the bioavailability of chylomicron-derived Cholesterol in the liver for biliary hypersecretion into bile. These abnormalities induced supersaturated bile and rapid Cholesterol crystallization.

Conclusions: The potent CCK-1R antagonist devazepide increases susceptibility to gallstone formation by impairing gallbladder emptying function, disrupting biliary Cholesterol metabolism and enhancing intestinal Cholesterol absorption in mice.