Hepatic bile acid transport increases in the postprandial state: A functional 11C-CSar PET/CT study in healthy humans

Abstract Background & Aims It is not known how hepatic bile acids transport kinetics changes postprandially in the intact liver. We used positron emission tomography (PET)/CT with the tracer [N-methyl-11C]cholylsarcosine (11C-CSar), a synthetic sarcosine conjugate of cholic acid, to quantify fasting and postprandial hepatic bile acid transport kinetics in healthy human subjects. Methods Six healthy human subjects underwent dynamic liver 11C-CSar PET/CT (60 min) during fasting and 15 minutes after ingestion of a standard liquid meal. Hepatobiliary secretion kinetics of 11C-CSar was calculated from PET data, blood samples (arterial and hepatic venous) and hepatic blood flow measured using indocyanine green infusion. Results In the postprandial state, hepatic blood perfusion increased on average 30% (p Conclusions The rate constant for the transport of bile acids from hepatocytes into biliary canaliculi and the bile flow increased significantly in the postprandial state. This reduced the mean 11C-CSar residence time in the hepatocytes. Lay summary Bile acids are important for digestion of dietary lipids including vitamins. We examined how the liver's secretion of bile acids into the intestines changes after a standard liquid meal. The transport of bile acids from liver cells into bile as well as bile flow were increased after the meal.