Effect of dietary cholesterol and indomethacin on cholelithiasis and gallbladder motility in guinea pig.

This study examines the effects of dietary cholesterol and subcutaneous indomethacin on gallstone formation, gallbladder motility, and bile composition in guinea pigs. Guinea pigs on cholesterol diets developed gallstones which were not primarily composed of cholesterol and were not prevented by indomethacin. Animals receiving cholesterol diets showed significant gallbladder enlargement which was inhibited by indomethacin. Cholesterol did not alter gallbladder pressure-volume relationships or the response to CCK, while indomethacin diminished gallbladder tone. Although cholesterol feeding did not appear to alter smooth muscle contractility in the guinea pig gallbladder, it caused significant gallbladder enlargement by a mechanism which may be dependent on prostaglandins.