Biochemical and Histochemical Study on Fatty Acid-Calcium Gallstones

Abstract

Chemical, mineralogical and histochemical investigations of fatty acid-calcium stones were carried out in order to elucidate the mechanism of formation of gallstone components in general. The results obtained were as follows: 1) Systematic chemical analysis, infrared spectroscopy and gas chromatography of fatty acid-calcium gallstones obtained from 3 patients revealed that the predominant fatty acid in these stones was palmitic acid. Small amounts of stearic acid and oleic acid were also detected. 2) Fatty acidcalcium gallstones showed a laminated structure characterized by eccentrically arranged layers. Examinations under polarized light revealed fatty acid-calcium crystals between the layers of bile pigment particles which extended outwards in a fan-shape. 3) Histochemical examinations revealed the presence of diffuse networks of acid mucopolysaccharides containing sulfated radicals in fatty acid-calcium stones. Detailed examination of the net-works revealed a ubiquitous presence of acid mucopolysaccharides in the spaces between fatty acid-calcium crystals as well as in the layers, suggesting that these substances were playing an important role in holding crystals and particles together as bridges among other components of the stones. 4) On the basis of these findings it was concluded that severe infection of the biliary tract, release of fatty acid-calcium into the bile by enzymes and concrement formation of composite materials by acid mucopolysaccharide are essential in the formation of gallstones ofthis type.