BINDING OF A LABELED ANTI-DEPRESSANT TO RAT-BRAIN TISSUE

[3H]desipramine. a labeled tricyclic antidepressant, binds specifically to rat brain crude synaptosomal and membranal preparations. The binding is rapid, displaceable and saturable with a IC50 value of 4 × 10-6M. The maximal number of sites is 18-26 nmoles/g original tissue in the synaptosomal preparation and only 6-8 nmoles/g in the membranal preparation. Scatchard plots of the binding data are not linear, suggesting a heterogenous set of binding sites. Pargyline and a number of neurotransmitters and agonists have only a small effect on desipramine binding; whereas various neurotransmitter antagonists inhibit the binding at the μM concentration range. © 1979.