Role of opioid peptides in the regulation of lymphocytic proliferation and in the change of the Thl/Th2-cytokinic profile

Abstract

The authors studied a role of β-endorphin during the blockade of opiate receptors and selective μ- and δ-receptor agonists DAMGO and DADLE to the reaction of lymphocytic blast-cell transformation (RLBCT) and to the production of IL-1β, γ-IFN, and IL-4 in the presence of phytohemagglutinin (PHA). It was found that β-endorphin, naloxone, and the selective μ- and δ-receptor agonists stimulated PHA-induced RLBCT, without affecting a spontaneous proliferative response. During opiate receptor blockade, the effect of β-endorphin was not abolished, but, on the contrary, enhanced as naloxone exerted a stimulating effect on RLBCT. A proliferative response was not recorded during preliminary one-hour opioid treatment, β-endorphin, naloxone, and DADLW enhanced the PHA-induced production of IL-4. Naloxone exerted a heterodirectional effect on the synthesis of this cytokine, by inhibiting it spontaneously. The opioid peptides and naloxone produced no effect on the production of IL-1β) and γ-IFN. It is suggested that β-endorphin, naloxone, and the selective μ- and δ-receptor agonists promote the differentiation of Т lymphocytes towards Th2-cells.