Involvement of nicotinic and muscarinic acetylcholine receptors on striatal HgCl2-induced dopamine release in freely moving rats

The possible role of acetylcholine receptors on the HgCl2-induced dopamine (DA) release from rat striatum was investigated by using in vivo brain microdialysis technique after administration of selective nicotinic and muscarinic receptor antagonists, mecamylamine and atropine, respectively. Intrastriatal infusion of 1 mM HgCl2 increased striatal DA to 1717.2 ± 375.4% respect to basal levels. Infusion of 1 mM HgCl2 in 1 mM mecamylamine pretreated animals produced an increase on striatal DA levels 58% less than that induced in non-pretreated animals. In the case of atropine, this treatment reduced 62% the effect produced by HgCl2 as compared to non-pretreated rats. These data show that acetylcholine receptors could participate on HgCl2-induced dopamine release since administration of nicotinic and muscarinic receptor antagonists reduces HgCl2 effects on DA release.