Iron-dextran injection into the substantia nigra in rats decreases striatal dopamine content ipsilateral to the injury site and impairs motor function

Abstract

Iron chloride injections into the rat SNc can cause chronic decreases in striatal dopamine (DA) levels. However, changes in striatal DA content after iron-dextran injection into rat SNc have not been completely elucidated. The aim of this work was to measure striatal DA concentrations after iron-dextran injection into the SNc. We divided 40 male Wistar rats into five groups, including control, saline injected then sacrificed 7 days or 30 days later, and iron-dextran injected then sacrificed 7 days or 30 days later. Striatal DA content was measured in control animals and in all animals sacrificed 7 days or 30 days after injection, and motor performance was assessed in iron-dextran and saline injected groups 30 days after injection. The striatal DA levels were determined using HPLC. There were significant (P < 0.05) decreases in DA concentrations in the striatum ipsilateral to the injection site in the iron-dextran treated rats compared to control and saline-injected rats. There were no significant differences in DA concentration between the sham-operated (i.e., saline-injected) and control rats. We also observed motor deficits in the iron-dextran injected rats. The striatal DA reduction observed after iron-dextran injection may be attributable to iron-induced oxidative injury in the SNc. Motor deficits, in turn, may be explained by subsequent disturbances in striatal and cortical dopaminergic neuromodulation.