Bilirubin conjugate changes in the bile of gallbladders containing gallstones

Abstract

Gallbladder bile was obtained at laparoscopic cholecystectomy from 31 patients with gallstones, and duodenal aspirates from 18 normal controls. Bile pigments (9 conjugates and unconjugated bilirubin) were analyzed by high-performance liquid chromatography. The average proportional composition of the bile pigments from the patients with gallstones was characteristically different from the controls. Whereas the average values for the principal conjugates in the controls were bilirubin diglucuronide 83.4%, bifirubin monoglucuronide 10.1%, bifirubin monoglucuronide monoglucoside 4.5%, and bilirubin monoglucuronide monoxyloside 1.0%, the corresponding values in the biles from the patients with gallstones were 66.3%, 20.6%, 6.5%, and 2.8%, respectively. Values from the more minor conjugates and unconjugated bilirubin were less than 2% in either data set. In samples obtained in 9 of the gallstone patients early and late in the procedure, no significant change was found. Over the spectrum of findings in the gallstone patients, as the proportion of bilirubin diglucuronide became smaller, that of bilirubin monoglucuronide increased substantially, whereas those of bilirubin monoglucuronide monoglucoside and bilirubin monoglucuronide monoxyloside increased to a small extent. The findings suggest that bilirubin diglucuronide hydrolysis occurs in the gallbladder bile of gallstone patients, with the production of bilirubin monoglucuronide, and that if further hydrolysis of bilirubin monoglucuronide occurs with the formation of unconjugated bilirubin, the latter does not ordinarily increase because it is being absorbed. Stasis with increased gallbladder residence time was likely present in some of the patients. The hydrolytic activity is hypothesized to arise from the gallbladder wall, or the process to be spontaneous, and its effects to be amplified by any increase in gallbladder residence time.