Bile Plow Rates and Biliary Motility Quantitated by Intravital Microscopy

Abstract

Intravital microscopy was adapted to document and quantitate in vivo biliary motility and bile flow rates in guinea pigs. The movement of 10 μ_m diameter fluorescent beads in the bile duct was used to measure bile flow rates. Using this method, bile flow rates were comparable to those determined by measuring the volume of bile collected from the papilla, but greater (P<0.01) than the volume of bile collected from a bile duct cannula. During intravital microscopy, biliary contractions were only detected at the choledochoduodenal junction. While fasting, the sphincter ductus choledochi contracted at 6.0 ± 1.0 per min and the ampulla at 1.2 ± 0.2 per min. Postprandially, sphincter contractions had a decreased frequency and an increased duration while both duration and frequency of ampullary contractions increased. The volume of bile collected from a bile duct cannula postprandially did not change. This data suggested that the choledochoduodenal junction had a propulsive function and postprandial changes in motility were due to neurohumoral factors rather than passive response to changes in bile flow rates. Intravital microscopy proved to be a sensitive in vivo technique in which to quantitate bile flow rates and biliary motility.