Fructose 1,6 biphosphate (F1,6BP) exerts a protective effect in several in vitro models of induced injury and in isolated organs; however, few studies have been performed using in vivo
hypothermia. Here we studied the effects of deep
hypothermia (21ºC) and
rewarming in anaesthetised rats after F1,6BP administration (2 g/kg
body weight).
Acid-base and oxidative stress parameters (plasma
malondialdehyde and
glutathione, and erythrocyte
antioxidant enzymes) were evaluated. Erythrocyte and leukocyte numbers in blood and plasma
nitric oxide were also measured 3 h after F1,6BP administration in normothermia animals. In the absence of F1,6BP
metabolic acidosis developed after
rewarming. Oxidative stress was also evident after
rewarming, as shown by a decrease in
thiol groups and in erythrocyte
superoxide dismutase,
catalase and GSH-
peroxidase, which corresponded to an increase in AST in rewarmed animals. These effects were reverted in rats treated with F1,6BP. Blood samples of F1,6BP-treated animals showed a significant increase in plasma
nitric oxide 3 h after administration, coinciding with a significant rise in leukocyte number. F1,6BP protection may be due to the decrease in oxidative stress and to the preservation of the
antioxidant pool. In addition, we propose that the reduction in extracellular
acidosis may be due to improved tissue perfusion during
rewarming and that
nitric oxide may play a central role.