Superoxide dismutase in rats with sepsis. Effect on survival rate and amino acid transport
B. W. Warner, P. O. Hasselgren, J. H. James, H. Bialkowska, D. F. Rigel, C. Ogle and J. E. Fischer
Department of Surgery, University of Cincinnati Medical Center, OH 45267.
In a recent study, administration of the free radical scavenger superoxide
dismutase (SOD) improved survival in rats with sepsis when administered two
hours before induction of sepsis. The present study was designed to
determine whether free radical-induced membrane damage is involved in the
pathogenesis of decreased muscle amino acid uptake, noted in sepsis.
Additionally, the effect on survival rate of SOD given after the onset of
sepsis was studied. Sepsis was induced by cecal ligation and puncture in
rats. Amino acid transport in incubated soleus muscles was studied using
tritiated alpha-aminoisobutyric acid. Amino acid uptake was significantly
reduced in muscle from rats with sepsis. Administration of SOD before
induction of sepsis or added in vitro to incubated muscles with sepsis had
no effect on alpha-aminoisobutyric acid uptake. Survival rate was not
increased when SOD was given two hours after cecal ligation and puncture.
The results suggest that free radical-induced membrane damage is not the
mechanism of inhibited muscle amino acid transport in sepsis. Since
survival was not improved by SOD administered after induction of sepsis,
the role of the enzyme in the treatment of sepsis may be questioned.
