Pharmacological modifications of dopamine transmission do not influence the striatal in vivo binding of [3H]mazindol or [3H]cocaine in mice

F Thibaut (1) , J J Bonnet (1) , J. M. Vaugeois (1) , J Costentin (1)

1 ESA 6036 - Unité de neuropsychopharmacologie expérimentale

We have considered the in vivo striatal binding of two ligands of the neuronal dopamine uptake complex [3H]cocaine and [3H]mazindol. The [3H]cocaine tracer dose labelled the dopamine uptake complex in striatum but not the noradrenaline complex in cerebellum. On the contrary, the [3H]mazindol tracer dose induced a marked labelling of the noradrenaline uptake complex in cerebellum; its prevention by desipramine (5 mg/kg) increased simultaneously the cerebral bioavailability and thereby the striatal labelling of the dopamine transporter. In mice submitted to treatments modifying dopaminergic transmission either to decrease it (gammabutyrolactone, 750 mg/kg, i.p.) or to increase it (L-DOPA, 200 mg/kg, i.p., dexamphetamine, 4 mg/kg, s.c., or their combination), only dexamphetamine pretreatment significantly reduced [3H]cocaine and [3H]mazindol binding. Thus it appears that the level of dopamine transmission would not interfere with the in vivo quantification of striatal dopamine uptake sites assessed with either ligands.

Domaines: Médecine humaine et pathologie

F Thibaut, J J Bonnet, J. M. Vaugeois, J Costentin. Pharmacological modifications of dopamine transmission do not influence the striatal in vivo binding of [3H]mazindol or [3H]cocaine in mice. Neuroscience Letters, 1996, 205 (3), pp.145-8. ⟨10.1016/0304-3940(96)12399-5⟩. ⟨hal-02186987⟩