Lack of effect of chronic desipramine treatment on dopaminergic activity in the nucleus accumbens of the rat
The binding of [3H]SCH 23390 to dopamine (DA) D1-receptors was measured in the nucleus accumbens of rats treated chronically with desipramine for 14 days. DA D1- and D2-receptor binding using [3H]SCH 23390 and [3H]spiperone, respectively as ligands, was determined in rats treated for 28 days. Neither B(max) nor K(d) values were influenced by chronic desipramine treatment. In addition, chronic desipramine treatment (28 days) did not influence the dose dependent, quinpirole (10 - 1000 nM)-mediated inhibition of the electrically stimulated release of [3H]DA and [14C]ACh from nucleus accumbens sclices or the dose dependent increase in [3H]DA release and decrease in [14C]ACh release in the presence of 1 and 10 μM nomifensine. Therefore, our results suggest that the effect of chronic antidepressant treatment cannot be attributed to changes in either DA D1- or D2-receptor binding or DA D2-receptor function in the nucleus accumbens.