Effect of repeated administration of manganese on the striatal cholinergic and dopaminergic receptors in the rat.

Previous studies suggest that chronic administration of manganese produces symptoms akin to Parkinson's disease, which is believed to be due to derangement in the central cholinergic and dopaminergic system. In the present study the effect of repeated administration of manganese chloride to male Sprague-Dawley rats on the binding of [3H]spiroperidol and [3H]quinuclidinyl benzilate to striatal dopaminergic and cholinergic receptors, respectively, was determined. Daily intraperitoneal injections of manganese chloride (15 mg/kg) for 15 days followed by a 24 h drug-free period did not alter the receptor density (Bmax) or the apparent dissociation constant (Kd) of either [3H]spiroperidol or [3H]quinuclidinyl benzilate to the rat striatal membranes. It is concluded that chronic treatment with manganese does not change the plasticity of post-synaptic dopaminergic or cholinergic receptors in the rat striatum.