Lysosomal enzyme activities in gallbladder mucosa of gallstone-free subjects and patients with gallstones.

Background/aims: Gallstone patients have a reduced cellular lysosome content in the gallbladder mucosa cells compared with gallstone-free subjects. The purpose of the study was to further evaluate the possible role of lysosomes in the pathogenesis of cholesterol gallstone formation in humans.

Methods: Lysosomal enzyme activities were assayed in gallbladder mucosa and for comparison in liver specimens of 19 gallstone-free subjects and 24 gallstone patients undergoing cholecystectomy.

Results: Gallstone patients had 25-50% lower activities of the lysosomal proteases cathepsin B, D and L in their gallbladder mucosa compared with gallstone-free subjects. The activity of acid phosphatase also tended to be decreased in gallstone patients. The liver lysosomal enzyme activities were not significantly different between the two groups.

Conclusions: The results show that gallstone patients have diminished lysosomal enzyme activities in the gallbladder mucosa, a finding which may be related to decreased intracellular degradation of proteins and/or mucin in the mucosal cells. This may lead to a higher concentration of mucin in gallbladder bile and thus an increased risk of precipitation of cholesterol crystals and gallstone formation.