Diabetes, Vol 36, Issue 2 169-173, Copyright © 1987 by American Diabetes Association
Starvation-related alterations in free radical tissue defense mechanisms in rats
SA Wohaieb and DV Godin
Alterations in endogenous free radical-scavenging defense mechanisms of rat
tissues after body weight loss (induced by starvation for 72 h) associated
with hypoinsulinemia were investigated. The activities of catalase (CAT),
superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), and
glutathione (GSSG) reductase as well as levels of reduced glutathione (GSH)
were examined in several tissues and in erythrocytes. A complex pattern of
changes was observed. CAT activities were increased in the heart and
pancreas and decreased in the liver. SOD levels were decreased in the heart
and increased in the kidney and pancreas. GSH-PX activities were increased
only in the kidney, and levels of GSH were decreased only in the liver of
starved animals. Erythrocytes from starved animals showed no alterations in
the levels of major free radical-scavenging enzymes. However, GSSG
reductase levels were lower in erythrocytes from starved animals, and this
was associated with an increased susceptibility to H2O2-induced GSH
depletion. Paradoxically, H2O2-induced malondialdehyde (MDA) production in
erythrocytes from starved animals was lower than that in control
erythrocytes. Our results suggest that, in studies of experimental
diabetes, attention must be given to the influence of body weight loss per
se on the biochemical alterations associated with this disease.