Intrahepatic blood flow distribution in the perfused rat liver:
effect of hepatic artery perfusion.
Burczynski, Frank J., Bruce A. Luxon, and Richard A. Weisiger.
Department of Medicine and the Liver Center, 357 Sciences,
University of California, San Francisco, California, 94143-0538
APStracts 3:0088G, 1996.
Variations in blood flow to different sinusoids within the liver can
prevent uniform uptake of solutes from plasma and contribute to
cellular ischemia in low-flow states. However, the degree of
variability and the role of hepatic artery perfusion in maintaining
uniform flow are poorly defined. We used an indicator dilution
technique to compare the distribution of sinusoidal transit times in
isolated rat livers perfused through the portal vein alone with
livers perfused using both portal vein and hepatic artery.
Physiologic flow rates were used in each case (1.2 0.3 ml[tilde]nmin
-1[tilde]ng liver-1), but the second group received 32% of flow
through the hepatic artery. Intralobular flow heterogeneity was
further assessed by gamma counting of small (100 mg) pieces of the
liver following bolus injection of 5 mCi of a highly extracted
compound ([125I]triiodothryronine) into the portal vein. Hepatic
artery perfusion had no significant effect on mean sinusoidal transit
time or intrahepatic distribution volume for [51Cr]erythrocytes or
[125I]albumin. Analysis of the outflow profiles indicated that
hepatic artery perfusion did not affect transit time dispersion.
However, heterogeneity of flow to individual portions of the liver,
measured as the coefficient of variation, increased from 19% to 30%.
These results indicate relatively uniform perfusion of the sinusoids
in the portally perfused rat liver, and that additional perfusion of
the hepatic artery does not further improve hemodynamics. These
results have significance for the design and interpretation of
transport studies using the perfused rat liver model.
Received 12 April 1993; accepted in final form 18 March 1996.
APS Manuscript Number G132-3.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 8 May 96