Glutamine is highly effective in preventing in vivo cobalt-induced oxidative stress in rat liver.
OBJECTIVE
To evaluate the in vivo effect of glutamine on cobalt-generated oxidative stress and (HO-1) induction in rat liver.


METHODS
Fasted female Wistar rats received a single injection of cobalt chloride (375 micromol/kg body weight) and then were killed at different times. Lipid peroxidation and soluble and enzymatic antioxidant defense system (reduced glutathione (GSH), catalase (CAT), glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD)) were measured in liver homogenates. Ferritin and ferritin iron contents as well as heme oxygenase-1 (HO-1) activity and expression were also determined. The antioxidant properties of glutamine (Gln) were also evaluated.


RESULTS
Cobalt chloride increased lipid peroxidation (50% over control values) 1 h after treatment. GSH reached a minimum at 3 h (40%) increasing thereafter. Twelve hours after CoCl2 injection, the antioxidant enzymes CAT, GSH-Px and SOD also diminished by about 30%. Heme oxygenase-1 induction was observed 6 h after treatment reaching a maximum value of 14-fold over the controls, 12 h after cobalt treatment. A 1.7-fold increase in ferritin and ferritin-bound iron 24 h after treatment were also obtained. Administration of glutamine (300 mg/kg body weight) by gavage 24 h before CoCl2 treatment entirely prevented the increase in thiobarbituric acid reactive substances (TBARS) content, the decrease in GSH levels, and partially reverted heme oxygenase-1 induction.


CONCLUSIONS
These results suggested that a natural product such as glutamine prevents glutathione depletion and consequently heme oxygenase induction.
Gonzales
Soledad
S
Departamento de Química Biológica, Facultad de Farmacia y Bioquimica, Universidad de Buenos Aires, Junin 956, Buenos Aires, 1113, Argentina.
Polizio
Ariel-H
AH
Erario
María-A
MA
Tomaro
María-L
ML
D000818:Animals; D002374:Catalase / Q000378:metabolism; D003035:Cobalt / Q000037:antagonists & inhibitors / Q000633:toxicity*; D005260:Female; D005973:Glutamine / Q000494:pharmacology*; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000378:metabolism
D005973:Glutamine; D003035:Cobalt; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005978:Glutathione