AJP - Gastrointestinal and Liver Physiology, Vol 256, Issue 6 949-G956, Copyright © 1989 by American Physiological Society
Effect of adenine on liver nucleotide after fructose loading by 31P-NMR
W. J. Thoma and K. Ugurbil
Department of Biochemistry, University of Minnesota, Navarre 55392.
Livers from 125- to 150-g rats were perfused and the effect of fructose
metabolism on liver energetics was observed using 31P nuclear magnetic
resonance (NMR). Livers were exposed to fructose in a nonrecirculating
manner for approximately 15 min and monitored for recovery for 30 min. At
concentrations ranging from 1 to 25 mM, fructose exposure led to depletion
of the nucleoside triphosphate level. Subsequently, the nucleoside
triphosphate level recovered fully at a fructose concentration of 1 mM;
however, recovery was only 65% of the initial values if the fructose
concentration was 10 mM and 55% if the concentration was 25 mM. Adenine was
found to protect nucleoside triphosphate levels against the adverse effects
of fructose by blocking the deamination of AMP. In the presence of adenine,
AMP accumulation was observed in the NMR spectra upon exposure of the liver
to fructose.
