Emerging regulatory roles of opioid peptides, endogenous morphine, and opioid receptor subtypes in immunomodulatory processes: Metabolic, behavioral, and evolutionary perspectives.

Emerging regulatory roles of opioid peptides, endogenous morphine, and opioid receptor subtypes in immunomodulatory processes: Metabolic, behavioral, and evolutionary perspectives. Immunol Lett. 2020 Aug 19;: Authors: Esch T, Kream RM, Stefano GB Abstract Integrated behavioral paradigms such as nociceptive processing coupled to anti-nociceptive responsiveness include systemically-mediated states of alertness, vigilance, motivation, and avoidance. Within a historical and cultural context, opium and its biologically active compounds, codeine and morphine, have been widely used as frontline anti-nociceptive agents. In eukaryotic cells, opiate alkaloids and opioid peptides were evolutionarily fashioned as regulatory factors in neuroimmune, vascular immune, and systemic immune communication and auto-immunoregulation. The significance of opioidergic regulation of immune function was validated by the identification of novel μ and δ opioid receptors on circulating leukocytes. The novel μ3 opioid receptor subtype has been characterized as an opioid peptide-insensitive and opiate alkaloid-selective G protein-coupled receptor (GPCR) that is functionally linked to the activation of constitutive nitric oxide synthase (cNOS). Opioid peptides stimulate granulocyte and immunocyte activation and chemotaxis via activation of a novel leukocyte δ2 receptor subtype. However, opiate alkaloid μ3 receptor agonists inhibit these same cellular activities...
Source: Immunology Letters - Category: Allergy & Immunology Authors: Tags: Immunol Lett Source Type: research