The effect of dopaminergic agents on cell-mediated immune response in mice.

The aim of the study was to determine the effect of selective dopaminergic agents [(+/-)-SKF-81297 (D1 agonist), R(-)-2,10,11-trihydroxy-N-propyl-noraporphine (D2 agonist), pergolid (D agonist), R(+)-SCH-23390 (D1 antagonist), S(-)-eticlopride (D2 antagonist) and cis-(Z)-flupenthixol (D antagonist)] on cell-mediated immune response in vivo and in vitro and to verify the presence of dopamine receptors on murine splenocytes. The tested dopaminergic compounds exhibited a pronounced inhibitory effect on T-dependent immunity. They suppressed alloantigen-induced immune response in vivo and in vitro, IL-2 production was also markedly reduced. No substantial difference was found between the effect of dopamine agonists and antagonists or among ligands of subtypes of dopamine receptors. The effect of dopaminergic agents in vitro indicates a direct interaction with immunocompetent cells at the peripheral level. As the binding studies did not confirm the presence of dopamine receptors on splenocytes, the immunosuppressive efficacy of dopaminergic agents does not seem to be mediated via specific dopamine receptors.