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

OBJECTIVE

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.