The anticataleptic effect of 7-OH-DPAT: are dopamine D3 receptors involved?

The paper examined the effect of 7-OH-DPAT (7-hydroxy-N,N-di-n-propyl-2-aminotetralin), a dopamine D3 receptors-prefering agonist, on the catalepsy evoked by reserpine, haloperidol and fluphenazine in rats (male Wistar), as well as the influence of nafadotride, a dopamine D3 receptors-prefering antagonist, on that effect. The obtained results show that 7-OH-DPAT, as well as L-DOPA, a drug of choice in the therapy of Parkinson's disease, used for comparison, antagonize the catalepsy induced by reserpine, haloperidol and fluphenazine. Nafadotride, used in a dose (0.2 mg/kg) which inhibits the 7-OH-DPAT-evoked locomotor hyperactivity but does not affect the hypermotility induced by amphetamine and quinpirole, antagonizes the anticataleptic effect of 7-OH-DPAT or L-DOPA. It is therefore assumed that dopamine D3 receptors are involved in the anticataleptic effect of both 7-OH-DPAT and L-DOPA.