SUITABILITY CRITERIA FOR COMPARTMENTAL ANALYSIS OF THE PLASMA-CLEARANCE CURVE OF EXOGENOUS CHOLEPHILS - I-131 ROSE-BENGAL FULFILLS THESE CRITERIA

  • 1 January 1979
    • journal article
    • research article
    • Vol. 30  (4) , 211-215
Abstract
Hepatic clearance of exogenous cholephils involves at least 3 transfers: uptake by the liver, reflux from hepatocytes into the plasma and intracellular transport followed by active secretion in bile. Compartmental analysis may be applied to the plasma disappearance curve to calculate the fractional transfer rates. The 131I Rose Bengal (131I RB) fills the requirements of such an analysis, contrary to bromsulphthalein and indocyanine green, which were used until now. 131I RB does not undergo enterohepatic cycle and is not metabolized by the liver. In the preparation used, it behaves like a homogeneous substance, remains stable in the serum as long as 25 h after its injection and may be bound completely with human albumin in vitro prior to administration. Under these conditions, the material which is cleared by the liver is homogeneous. The use of tracer instead of loading doses avoids any toxic effects on transport systems and results in plasma and liver concentrations negligable in comparison with the Km of membrane transport and compatible with 1st order kinetics.