Role of voltage-gated calcium channels on striatal dopamine release induced by inorganic mercury in freely moving rats

Abstract The possible role of voltage-sensitive calcium channels (VSCC) activation on the HgCl 2 -induced dopamine release was investigated using selective VSCC blockers and the dopamine levels were measured by HPLC from samples obtained by in vivo brain microdialysis. Infusion of HgCl 2 in nicardipine (10 or 100 μM) or flunaricine (10 μM) pretreated animals had no significant effect on dopamine release induced by HgCl 2 . Pretreatment with 100 μM flunaricine, 20 μM ω-conotoxin MVIIC, or ω-conotoxin GVIA significantly decreased the HgCl 2 -induced dopamine release over 61%, 88%, and 99%, respectively. HgCl 2 -induced dopamine release could be produced, at least in part, by activation of VSCC at dopaminergic terminals, especially N- and P/Q-type.