The Mechanism of Bile Regurgitation Experimental Approach with Radioisotope.

In attempt to elucidate the kinetic mechanism of biliary regurgitation, the rabbit livers were subjected to measurement of bile secretion pressure under various conditions, and retrograde intrabiliary injection of radioactive iodine and India ink particles were carried out at various pressures to study their transfer into the blood stream. Electron and light microscopic studies were performed simultaneously. 1. At a pressure a few cm of water figher than the ile sevretion presure, a communication was established between the biliary tree and blood stream. This communication allowed passage of PVP of molecular weight of 35,000, but not India ink of the size of 200 Å. 2. Under high infusion pressures (twice the secretion pressure) a wide communication was established whereby India ink was transferred in the blood stream. However, this communication was transient and no communication was demonstrable when the infusion pressure was reduced. 3. It is suggested that in the early stages of biliary obstruction, desmosomes are separated noncontinually, and bile is pressed out from the bile canaliculi into the space of Disse across intercellular spaces.