Continuous monitoring of the biliary excretion of a pulse of labelled compounds.

A simple method allowing the continuous monitoring of the biliary excretion of a labelled, pulse-injected compound in a single-pass perfused rat liver is described. The collection device is a mini-strip-chart recorder: bile is collected on its moving paper as a uniform trail that dries almost instantaneously. After rapid injection into the portal vein, the biliary excretion of a labelled compound can be assessed measuring the radioactivity on the paper by cutting and counting narrow strips of paper or by a radiochromatogram scanner. Experiments performed with [14C]-bilirubin, [3H]-taurocholate, and [14C]-nitrofurazone attest the validity of this technique, which can potentially improve the accuracy of hepatic transport studies in the isolated organ as well as in the intact animal.