Abstract: | The data obtained indicate that rimorphin (0.1 mg/kg), a specific kappa-agonist, evoked a significant inhibition of the immune response in CBA mice. Pretreatment of the animals with 8-OH-DPAT (0.1 mg/kg), a selective serotonin (5-HT) agonist, activating presynaptic 5-HT(1A) receptors, or WAY-100635 (1.0 mg/kg), a selective 5-HT(1A) receptors blocker of postsynaptic 5-HTIA receptors, prevents kappa-opioid effect. The present data indicate that kappa-opioid-induced immunosuppression is due to the involvement of the 5-HT-ergic mechanisms that are modulated via pre- and postsynaptic 5-HT(1A) receptors. |