Identification of Opioid Receptors in the Immune System Using a Novel Combination of Selective Opioid Ligands and Indirect Phycoerythrin Immunofluorescence

Author(s):  
Diane M. P. Lawrence ◽  
Sydney Archer ◽  
Jean M. Bidlack
1989 ◽  
Vol 122 (1) ◽  
pp. 161-168 ◽  
Author(s):  
D. J. J. Carr ◽  
B. R. DeCosta ◽  
C.-H. Kim ◽  
A. E. Jacobson ◽  
V. Guarcello ◽  
...  

ABSTRACT Opioid peptides have been shown to modulate various parameters of both the humoral and cellular arms of the immune system. The modulatory capacity of the peptides can often be substantially reduced in the presence of naloxone, an opioid receptor antagonist, indicating a classical ligand-receptor interaction. In order to characterize these interactions further, we investigated the characteristics of opioid receptors on a macrophage cell line, P388d1. A δ-class opioid receptor was found with an Mr of 58 000. We also identified opioid receptors on MOLT-4 (T-cell) and IM-9 (B cell) cell lines as well as thymocytes and T celland B cell-enriched populations. Using the central (brain) κ-selective agonist, U-69,593, it was also determined that P388d1 cells possess κ-like opioid receptors. Scatchard analysis of the binding of [3H]U-69,593 revealed a single population of sites with a dissociation constant of 17 ± 3 (s.e.m.) nmol/l and a total number of binding sites of 53·8 ± 1·0 (s.e.m.) fmol/106 cells. Moreover, the racemic κ-selective agonist U-50,488H was able to displace 50% of [3H]U-69,593 binding at 8·0 nmol/l, whereas other opioid ligands such as [Met]-enkephalinamide (δ-selective) and [d-Ala2,N - Me - Phe4,Gly5 - ol] - enkephalin (μ - selective) were ineffective displacers of [3H]U-69,593 except at high concentrations. Journal of Endocrinology (1989) 122, 161–168


2020 ◽  
Vol 22 (1) ◽  
pp. 315
Author(s):  
Jana Brejchova ◽  
Vladimir Holan ◽  
Petr Svoboda

The observation of the immunomodulatory effects of opioid drugs opened the discussion about possible mechanisms of action and led researchers to consider the presence of opioid receptors (OR) in cells of the immune system. To date, numerous studies analyzing the expression of OR subtypes in animal and human immune cells have been performed. Some of them confirmed the expression of OR at both the mRNA and protein level, while others did not detect the receptor mRNA either. Although this topic remains controversial, further studies are constantly being published. The most recent articles suggested that the expression level of OR in human peripheral blood lymphocytes could help to evaluate the success of methadone maintenance therapy in former opioid addicts, or could serve as a biomarker for chronic pain diagnosis. However, the applicability of these findings to clinical practice needs to be verified by further investigations.


2021 ◽  
Vol 14 (677) ◽  
pp. eaav0320
Author(s):  
Tao Che ◽  
Hemlata Dwivedi-Agnihotri ◽  
Arun K. Shukla ◽  
Bryan L. Roth

The opioid crisis represents a major worldwide public health crisis that has accelerated the search for safer and more effective opioids. Over the past few years, the identification of biased opioid ligands capable of eliciting selective functional responses has provided an alternative avenue to develop novel therapeutics without the side effects of current opioid medications. However, whether biased agonism or other pharmacological properties, such as partial agonism (or low efficacy), account for the therapeutic benefits remains questionable. Here, we provide a summary of the current status of biased opioid ligands that target the μ- and κ-opioid receptors and highlight advances in preclinical and clinical trials of some of these ligands. We also discuss an example of structure-based biased ligand discovery at the μ-opioid receptor, an approach that could revolutionize drug discovery at opioid and other receptors. Last, we briefly discuss caveats and future directions for this important area of research.


2021 ◽  
Vol 270 ◽  
pp. 113872
Author(s):  
Tao Hou ◽  
Fangfang Xu ◽  
Xingrong Peng ◽  
Han Zhou ◽  
Xiuli Zhang ◽  
...  

2005 ◽  
Vol 16 (4) ◽  
pp. 281-288
Author(s):  
DONALD H PENNING

Reports in the 1970's by Snyder and others of opioid receptors in the brain and the substantia gelatinosa of the spinal cord triggered a search for endogenous opioid ligands (β-endorphin and the encephalin peptides) which might modify pain transmission. It was not long after that morphine was administered into the human epidural space for pain control, including obstetric patients.


2006 ◽  
Vol 1 (3) ◽  
pp. 260-269 ◽  
Author(s):  
Jean M. Bidlack ◽  
Maxim Khimich ◽  
Amy L. Parkhill ◽  
Sarah Sumagin ◽  
Baoyong Sun ◽  
...  

2003 ◽  
Vol 31 (06) ◽  
pp. 955-965 ◽  
Author(s):  
Reina Sekido ◽  
Keisou Ishimaru ◽  
Masakazu Sakita

It has been reported by Stein et al. that the immune system and peripheral opioid receptors are involved in the control of pain accompanying inflammation. Electroacupuncture (EA) is used to relieve various kinds of pain. However, little is known about the effect of electroacupuncture analgesia (EAA) during hyperalgesia elicited by inflammation. The aim of the present study was to compare (1) the individual variation of EAA, (2) the durability of EAA, and (3) the effect of naloxone on EAA between normal rats and rats subjected to acute inflammatory pain. Carrageenan was subcutaneously administered by intraplantar (i.pl.) injection of the left hind paw to induce a nociceptive response. Nociceptive thresholds were measured using the paw pressure threshold (PPT). Rats received EA at 3 Hz in the left anterior tibial muscles for 1 hour after carrageenan injection. Naloxone was administered by intraperitoneal (i.p.) or i.pl. injection just before EA. EAA was elicited in 15 of 29 normal rats. These rats were divided into responders and non-responders. EAA in the responder group was almost completely antagonized by i.p. injection of naloxone. In contrast, in all the rats with carrageenan-induced inflammation, EAA was elicited, lasted for at least 24 hours after carrageenan injection, and was dose-dependently antagonized by i.pl. injection, but not significantly by i.p. injection of naloxone. It seems likely that the EAA in the rats with carrageenan-induced inflammation differs from that in normal rats, and these findings suggest that peripheral opioid receptors are involved in EAA during inflammatory conditions.


Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4257 ◽  
Author(s):  
Abdelfattah Faouzi ◽  
Balazs R. Varga ◽  
Susruta Majumdar

Achieving effective pain management is one of the major challenges associated with modern day medicine. Opioids, such as morphine, have been the reference treatment for moderate to severe acute pain not excluding chronic pain modalities. Opioids act through the opioid receptors, the family of G-protein coupled receptors (GPCRs) that mediate pain relief through both the central and peripheral nervous systems. Four types of opioid receptors have been described, including the μ-opioid receptor (MOR), κ-opioid receptor (KOR), δ-opioid receptor (DOR), and the nociceptin opioid peptide receptor (NOP receptor). Despite the proven success of opioids in treating pain, there are still some inherent limitations. All clinically approved MOR analgesics are associated with adverse effects, which include tolerance, dependence, addiction, constipation, and respiratory depression. On the other hand, KOR selective analgesics have found limited clinical utility because they cause sedation, anxiety, dysphoria, and hallucinations. DOR agonists have also been investigated but they have a tendency to cause convulsions. Ligands targeting NOP receptor have been reported in the preclinical literature to be useful as spinal analgesics and as entities against substance abuse disorders while mixed MOR/NOP receptor agonists are useful as analgesics. Ultimately, the goal of opioid-related drug development has always been to design and synthesize derivatives that are equally or more potent than morphine but most importantly are devoid of the dangerous residual side effects and abuse potential. One proposed strategy is to take advantage of biased agonism, in which distinct downstream pathways can be activated by different molecules working through the exact same receptor. It has been proposed that ligands not recruiting β-arrestin 2 or showing a preference for activating a specific G-protein mediated signal transduction pathway will function as safer analgesic across all opioid subtypes. This review will focus on the design and the pharmacological outcomes of biased ligands at the opioid receptors, aiming at achieving functional selectivity.


2020 ◽  
Vol 18 (29) ◽  
pp. 5533-5557
Author(s):  
Irina V. Sandulenko ◽  
Asmik A. Ambartsumyan ◽  
Sergey K. Moiseev

Fluorinated 4,5α-epoxymorphinans, opioid ligands for drug development and PET imaging of opioid receptors using [18F]tracers, are reviewed.


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