Basic Research
Copyright ©2005 Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jun 21, 2005; 11(23): 3533-3538
Published online Jun 21, 2005. doi: 10.3748/wjg.v11.i23.3533
Glutamine is highly effective in preventing in vivo cobalt-induced oxidative stress in rat liver
Soledad Gonzales, Ariel H. Polizio, María A. Erario, María L. Tomaro
Soledad Gonzales, Ariel H. Polizio, María A. Erario, María L. Tomaro, Departamento de Química Biológica, Facultad de Farmacia y Bioquímica, Universidad de Buenos, Argentina
Author contributions: All authors contributed equally to the work.
Supported by the Universidad de Buenos Aires (Argentina) and Consejo Nacional de Investigaciones Científicas y Técnicas Argentina
Correspondence to: María L. Tomaro, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956, Buenos Aires, 1113, Argentina. ptomaro@ffyb.uba.ar
Telephone: +54-11-4964-8237 Fax: +54-11-4508-3645
Received: September 8, 2004
Revised: September 9, 2004
Accepted: October 8, 2004
Published online: June 21, 2005
Abstract

AIM: 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 µmol/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.

CONCLUSION: These results suggested that a natural product such as glutamine prevents glutathione depletion and consequently heme oxygenase induction.

Keywords: Oxidative stress; Heme oxygenase; Glutathione; Glutamine; Iron; Liver