Effects of 5-HT2A receptor stimulation and blocking on immune response.

Experiments on CBA mice showed that selective stimulation of 2A serotonin receptors with DOI agonist (1 mg/kg) led to suppression of the immune response and reduction of the spleen and peripheral blood CD8(+)T cell counts with the cytotoxic/suppressor function. Selective blockade of these receptors with ketanserin (1 mg/kg) had an opposite effect: immunostimulation with an increase in CD8(+)T cell count in the spleen. These data indicate the involvement of 2A serotonin receptors in immunosuppressive mechanisms of serotoninergic system.