Intrastriatal iron perfusion releases dopamine: an in-vivo microdialysis study

We perfused iron as FeCl(3) directly into the striatum of normal rats and used the in vivo microdialysis technique to monitor striatal levels of dopamine (DA). KCl was perfused to assess the functional integrity of the DA receptors at the end of each dialysis experiment. Cu(+2) (as CuSO(4)) and Cl(-) (as NaCl) were perfused to compare the effects of Fe(+3) to that of other heavy metal and donors of Cl(-) anion. Perfusion of FeCl(3) (1 mM for 15 min) produced a 250% increase in striatal levels of DA. Perfusion of CuSO(4) (1 mM for 15 min) or NaCl (10 mM for 15 min) did not affect striatal DA levels. There was a significant increase in DA levels with KCl stimulation (56 mM for 15 min) after perfusion with FeCl(3). We conclude that iron releases DA from striatal nerve endings without the immediate destruction of the DA terminals. The implications of chronic release of dopamine as a cause of dopaminergic cell death are discussed.