Insulin plus zinc induces a favorable biochemical response effects on oxidative damage and dopamine levels in rat brain.

The aim was to determine the effect of zinc (Zn) and insulin on oxidative stress and levels of dopamine in brain of rats. Wistar rats were treated either with zinc alone or combined with insulin during 10 days. After the last dose blood glucose was measured. Their brains were extracted to measure HO, Ca, Mg ATPase, glutathione (GSH), lipid peroxidation (Tbars) and Dopamine. Zn does not possess anti-glycemic effect like Insulin however, it is noticeable that the combination of Insulin plus Zn induces a major glucose reduction (p < 0.0001) than Insulin alone. In cerebellum/medulla oblongata, the groups treated with Insulin and Zn show a significantly increase in dopamine (p < 0.005). Insulin plus Zn reduced GSH level in cortex. Insulin plus Zn reduced level of HO in Striatum and in cerebellum/medulla oblongata. Lipid peroxidation was significantly reduced by the administration of Insulin as in the combination of Insulin and Zn in all regions (p < 0.0001). In cerebellum medulla oblongata, ATPase activity showed an increase only in the group treated with Insulin + Zn. CONCLUSION: These results suggest that the use of insulin plus Zn produce favorable changes on oxidative stress and this as consequence on the levels of dopamine.