AJP - Gastrointestinal and Liver Physiology, Vol 243, Issue 6 518-G531, Copyright © 1982 by American Physiological Society
How to measure first-order hepatic transfer coefficients by distributed modeling of a recirculating rat liver perfusion system
B. A. Luxon, P. D. King and E. L. Forker
A digital computer is used to simulate solute disappearance curves evolving
in the reservoir of a rat liver perfusion system. The results show that it
is feasible to obtain good estimates of these kinetic parameters with only
approximate information about the distribution of sinusoidal flows and the
transfer function of the nonexchanging vasculature. By contrast
satisfactory estimates of the transfer coefficients for uptake and efflux
(but not excretion) are critically dependent on accurate measurements of
the system transit times. A perfusion system suitable for implementing the
method is tested and found to maintain normal liver function for upward of
60 min. The means to achieve the required volume and flow measurements are
discussed, and an empirical criterion is developed for recognizing
disappearance curves whose information content is too low to yield reliable
results.
