STUDIES OF I131-ALBUMIN CATABOLISM AND DISTRIBUTION IN NORMAL YOUNG MALE ADULTS*

Abstract

The behavior of radioiodinated albumin was investigated in 20 studies of 13 different normal young human males by means of an ethanol-fractionated, lightly radioiodinated albumin preparation, not subjected to heat treatment. Distribution of exchangeable albumin between the extravascular and intravascular compartments of the body was examined in detail by each of 4 general mathematical methods. The extravascular to intravascular (EV-IV) albumin mass ratios, calculated by the 4 methods, provided means ranging from 1.17 to 1. 76. A statistical comparison of these data is presented. The compatibility of fit of the experimental data to a number of multicompartmental models for describing albumin distribution and metabolism were tested. All models examined were based upon compatibility with the observed plasma data. The nearest compatibility with both the observed plasma and urinary data was found in only those models wherein catabolism occurs in, or in rapid exchange with, the plasma compartment.