Pyridoxine and Zanamivir Alter Levels of Dopamine in Brain of Rats with Induced Hyperglycemia by Inhibition of Oxidative Stress

The aim of this study was to evaluate the effect of pyridoxine and zanamivir on dopamine (DA) levels and biomarkers of oxidative stress in brain of rats in presence of sucrose. Thirty six Wistar rats divided in six groups, comprising of 6 rats each. The rats were made to receive for 5 consecutive days intraperitoneal administrations of the following: group 1 (saline solution (NaCl 0.9%), control), group 2 (zanamivir 2.5 mg kgG1 ), group 3 (pyridoxine 10 mg kgG1 ), group 4 (sucrose 20%), group 5 (zanamivir+sucrose) and group 6 (pyridoxine+sucrose). The animals were sacrificed at the end of treatment and their brains were dissected in cortex, hemispheres, cerebellum/stem to measure dopamine (DA), glutathione (GSH), lipoperoxidation (TBARS) and enzymatic activities of ATPase using previously validated methods. The levels of glucose were not altered in rats treated with zanamivir and pyridoxine in presence of sucrose. In hemispheres, the levels of DA decreased in groups 3 (pyridoxine) and 4 (sucrose). Glutathione increased in the groups 5 (zanamivir+sucrose) and 6 (pyridoxine+sucrose). In cerebellum/medulla oblongata, DA increased in groups 2 (zanamivir), 3, 5 and 6. In cerebellum/medulla oblongata and cortex peroxidation decreased in group 2, while ATPase activity increased in groups 2 and 3 in cortex regions. Alterations of dopamine levels were seen in animals treated with pyridoxine and zanamivir. Reduction of oxidative stress may be involved in these effects.