AJP - Endocrinology and Metabolism, Vol 262, Issue 3 E275-E281, Copyright © 1992 by American Physiological Society
Different roles of IL-1 and TNF on hemodynamics and interorgan amino acid metabolism in awake dogs
R. Fukushima, H. Saito, K. Taniwaka, T. Hiramatsu, Y. Morioka, T. Muto and N. N. Abumrad
Department of Surgery, University of Tokyo, Japan.
The present study examines the effects of interleukin 1 (IL-1) and tumor
necrosis factor (TNF) on various hemodynamic parameters and interorgan
fluxes of amino acids, glucose, and lactate in chronically catheterized
awake dogs. The dogs received 5 micrograms.kg-1.h-1 of either human
recombinant IL-1 beta or TNF intravenously for 2 h. Hemodynamic parameters
and substrate fluxes across the gut and liver were determined during and 2
h after discontinuation of the cytokine infusions. Substrate fluxes were
calculated by blood flows and arteriovenous differences. Both IL-1 and TNF
enhanced the uptake of alanine, uptake of lactate, and output of glucose by
the liver. These changes were associated with elevated arterial levels of
alanine and lactate while arterial levels of glucose decreased. Uptake of
glutamine by the liver was reduced by either IL-1 or TNF infusions. The
effects of IL-1 and TNF on the hemodynamic parameters and on gut amino acid
metabolism varied with the cytokine infused. IL-1 produced hyperdynamic
state, increased splanchnic blood flow, and enhanced glutamine uptake by
the gut. TNF infusion did not cause a hyperdynamic state, nor did it alter
the gut handling of amino acids. We conclude that IL-1 and TNF exert
distinct different effects on the systemic and hemodynamic parameters and
on interorgan balances of amino acids, glucose, and lactate across the gut
and the liver.
