Factors affecting the ionized calcium concentration in human bile

Influences of bile acid, phospholipid, cholesterol and pH on ionized calcium concentration in human common bile duct bile

Abstract

Ionized calcium is an important factor in calcium-containing gallstone formation. Total calcium, ionized calcium, total bile acid, phospholipid and cholesterol concentration and pH of human common bile duct bile obtained intraoperatively from 22 patients undergoing cholecystectomy were measured in order to analyze the factors affecting the ionized calcium concentration in human bile. The concentration of ionized calcium was correlated to the concentration of total calcium. Trapping of ionized calcium by bile acid and phospholipid seems to be an importa nt regulatory mechanism for maintaining the concentration of ionized calcium in human bile. pH and cholesterol appear not to have an important role. Our data also suggest that biliary secr etion of calcium is influenced by bile acid and phospholipid.