Increased acylCoA-cholesterol ester acyltransferase activity in gallbladder mucosa in patients with gallbladder cholesterolosis.

Abstract

Although cholesterolosis of the human gallbladder is a relatively common disease, its etiology has not been fully understood. The aim of this study was to determine this etiology. The lipid composition of the gallbladder mucosa and gallbladder bile and the enzyme activities (acylCoA-cholesterol ester acyltransferase [ACAT] and cholesterol ester hydrolase [CEH]) of the gallbladder mucosa were measured in control subjects, patients with cholesterolosis, and patients with cholesterol gallstone disease. Levels of cholesterol ester in gallbladder mucosa in patients with cholesterolosis (n = 12) were higher than those in control subjects (n = 8). With regard to the lipid content in gallbladder bile, no differences were found in concentrations of cholesterol, phospholipids, and bile acids among control subjects (n = 11), patients with cholesterolosis (n = 13), and those with cholesterol gallstone disease (n = 15). In gallbladder mucosa, ACAT activity was significantly higher in patients with cholesterolosis (n = 10) than in control subjects (n = 8), whereas CEH activity did not differ between the two groups. As a result, the ACAT/CEH activity ratio was higher in patients with cholesterolosis than in control subjects. It would be suggested that cholesterol ester synthesis of gallbladder mucosa might play an etiological role in the development of cholesterolosis.