The aims of this study were to examine the effect of exogenous prostaglandin on mucin secretion and to determine the role of nonmucin glycoproteins on gallstone formation in the prairie dog model of cholesterol cholelithiasis. The concentration of total glycoprotein and nonmucin glycoproteins was measured in gallbladder bile from four groups of prairie dogs fed a control diet or a diet supplemented with 1.2% cholesterol with or without simultaneous subcutaneous administration of prostaglandin El. Cholesterol feeding resulted in an increased concentration of concanavalin-A binding-proteins in gallbladder bile associated with an increase in pronucleating activity in uitro.
Treatment with prostaglandin El and cholesterol feeding was associated with a significant increase in the incidence of cholesterol gallstone formation. Prostaglandin El treatment in the cholesterol-fed animals increased biliary concentrations of total glycoprotein and concanavalin-A-binding glycoproteins. Therefore the increased biliary glycoprotein level in cholesterolfed, prostaglandin El-treated prairie dogs, which reflects higher levels of much and nonmucin glycoproteins, appears to be an important factor in gallstone formation. (HEPATOLOGY 1993;17:693-700.) Cholesterol gallstone formation is multifactorial, requiring simultaneous hepatic secretion of cholesterol supersaturated bile, nucleation of cholesterol monohydrate crystals in the gallbladder and subsequent growth and agglomeration of these crystals to form gallstones (1). The cholesterol-fed prairie dog is one of the best-characterized animal models for the study of cholesterol gallstone formation (2). Lee and colleagues