[The central mechanism of the immunomodulating action of vasopressin and its structural analogs]

It is shown that the effect of neuropeptides depends on the dose and their structure. Considerable immunostimulation is observed after administration of [8-arginine]vasopressin and des-9-glucine-[8-arginine]vasopressin as against the control. This stimulation is prevented by the preliminary heloperidol blockade of dopaminergic receptors, i.e. it is dopamine-dependent. At the same time, injection of tetrapeptide vesopressin-(2-5) induces deep immunosuppression in all the applied doses. The peptide immunosuppression is shown to be a result of interaction with another neuromediator (serotoninergic); it has no effect under preliminary cuproheptadine blockade of C-2 serotonin postsynaptic receptors. The immunomodulating effect of the neuropeptides studied is central one and is realized via the hypothalamus-hypophysis complex.