Rat biliary tree during short periods of obstruction of common duct

¹ Department of Physiology and Pharmacology, University of Cape Town, Cape Town, South Africa

The capacity of the biliary tree, and the residual volume of the original contents present at different time intervals following obstruction of the common duct, were measured at different pressures in experiments of short duration. The results showed: 1) the capacitance of the biliary tree increased with increasing back pressure; 2) the measured secretory rate was not reduced by back pressure; 3) leakage of bile from the biliary tree ("regurgitation") was absent (or constant) until the back pressure was about 75% of the maximum secretory pressure; 4) with the exception of a very small dead-space volume, the original contents of the biliary tree were removed exponentially during obstruction. It was concluded that biliary secretion continues unchecked during short periods of obstruction, that regurgitation occurs at sites which are uniformly distributed over most of the biliary tree, and that the "maximum secretory pressure" of the liver probably represents only the critical pressure at which secretion is equal to reabsorption.

Key Words: bile • liver • biliary pressure-volume curve • biliary regurgitation • biliary secretion • biliary tree model

Submitted on June 18, 1963