Hepatic biliary lipid secretion and gall bladder biliary lipid mass in gall stone patients: effect of ursodeoxycholic acid.

We have carried out overnight measurements of hepatic secretion rate and duodenal output of biliary lipids using a duodenal perfusion technique. We correlated these measurements with the fasting state mass of biliary lipids within the gall bladder on the following morning using a combined nasoduodenal intubation and isotope scanning technique. We studied six gall stone subjects before and during treatment with ursodeoxycholic acid 675 mg/day. Lipid mass within the gall bladder correlated with the corresponding overnight hepatic secretion rate for all three biliary lipids. During ursodeoxycholic acid treatment, there was an increase in gall bladder bile acid mass without significant change in cholesterol or phospholipid mass. We conclude that the mass of individual biliary lipids within the fasting gall bladder is influenced by overnight hepatic biliary lipid secretion rate; and that the effect of ursodeoxycholic acid (675 mg/day) on cholesterol saturation index of fasting gall bladder bile is mediated via an increase in bile acid mass rather than through a decrease in cholesterol mass within the gall bladder.