Loperamide Inhibits Gallbladder Inflammatory Fluid Secretion in Experimental Cholecystitis

Fluid secretion by the gallbladder mucosa is suggested to have a key pathophysiological role in acute cholecystitis, since it causes distension of the obstructed gallbladder. The present study investigates the actions of loperamide on the gallbladder function in experimental cholecystitis. Gallbladder fluid transport and motility were studied in vivo with a continuous perfusion technique. A net fluid secretion by the gallbladder mucosa was seen in cats in which cholecystitis was induced whereas there was a net fluid absorption from the gallbladder lumen in the control animals. The net fluid secretion in experimental cholecystitis was inhibited by loperamide (1 mg/kg), an effect that was blocked by naloxone (1 mg/kg), suggesting an involvement of specific opiate receptors. Loperamide (1 mg/kg) relaxed the normal gallbladder but had no significant effects on its fluid absorption. Since loperamide reduces mucosal fluid secretion in experimental cholecystitis without contracting the gallbladder wall, it is suggested that this peripherally acting opiate agonist could be useful in the treatment of patients with acute cholecystitis.