Mucosal alkaline phosphatase and bile lipids in the gallbladder in cholecystitis

Histochemically, alkaline phosphatase was localised in epithelial brush-border and capillary endothelium of the lamina propria in 41 gallbladders studied. Three distinct patterns of the brush-border enzyme distribution were observed, namely, complete delineation, patchy localisation and a brush-border totally devoid of enzyme activity. Where no histochemical activity was found, biliary chenodeoxycholate was 50 per cent. higher than in cases of patchy distribution and twice as high as in cases with complete staining of the brush-border. Conversely, biliary cholate levels were significantly higher in completely stained cases. Biliary cholesterol was higher in the cases with no histochemical activity and this was reflected in a significantly higher lithogenic index. Significant quantities of cholesterol esters were found in bile from the focal activity group only. Total alkaline phosphatase activity assayed in gallbladders from 112 patients with cholecystitis and/or lithiasis showed that activity was significantly lower in patients with pigment stones than patients with cholecystitis and/or cholesterol stones. This activity was not related to biliary lipid composition in the 77 bile samples analysed. This evidence indicates that biliary lipid composition is associated with the histochemical distribution of alkaline phosphatase in gallbladder mucosa.