Lithium inhibition of norepinephrine and dopamine receptors.

Sprague-Dawley rats (150-200 g), serving as their own controls, were evaluated for hyperactivity (HyA) and stereotyped behavior (SB) produced by chronic (1 week) ip administration of different doses of drugs that have differential NE and DA " agonist" properties. Drugs utilized were d- and l-amphetamine, metamphetamine, cocaine, and the specific and direct DA receptor agonist apomorphine. This was followed by 1 week of rest after which all rats received 3 weeks of lithium chloride (Li) subcutaneously. In the last week of Li administration, each rat also was given the same drug administered previously at the same dose. In all cases, Li decreased both HyA and SB, suggesting Li effects both at the pre- and postsynaptic neuron (receptor).