1
|
Hajhashemi V, Sadeghi H, Madab FK. Anti-inflammatory and antinociceptive effects of sitagliptin in animal models and possible mechanisms involved in the antinociceptive activity. Korean J Pain 2024; 37:26-33. [PMID: 38123184 PMCID: PMC10764209 DOI: 10.3344/kjp.23262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 11/24/2023] [Accepted: 12/03/2023] [Indexed: 12/23/2023] Open
Abstract
Background Sitagliptin is an antidiabetic drug that inhibits dipeptidyl peptidase-4 enzyme. This study aimed to investigate the antinociceptive and anti-inflammatory effects of sitagliptin in formalin and carrageenan tests and determine the possible mechanism(s) of its antinociceptive activity. Methods Male Swiss mice (25-30 g) and male Wistar rats (180-220 g) were used for formalin and carrageenan tests, respectively. In the formalin test, paw licking time and in the carrageenan test, paw thickness were considered as indexes of pain behavior and inflammation respectively. Three doses of sitagliptin (2.5, 5, and 10 mg/kg) were used in these tests. Also, several antagonists and enzyme inhibitors were used to evaluate the role of adrenergic, serotonergic, dopaminergic, and opioid receptors as well as the NO/cGMP/KATP pathway in the antinociceptive effect of sitagliptin (5 mg/kg). Results Sitagliptin showed significant antinociceptive and anti-inflammatory effects in the formalin and carrageenan tests respectively. In the carrageenan test, all three doses of sitagliptin significantly (P < 0.001) reduced paw thickness. Pretreatment with yohimbine, prazosin, propranolol, naloxone, and cyproheptadine could not reverse the antinociceptive effect of sitagliptin (5 mg/Kg), which indicates that adrenergic, opioid, and serotonin receptors (5HT2) are not involved in the antinociceptive effects. L-NAME, methylene blue, glibenclamide, ondansetron, and sulpiride were able to reverse this effect. Conclusions NO/cGMP/KATP, 5HT3 and D2 pathways play an important role in the antinociceptive effect of sitagliptin. Additionally significant anti-inflammatory effects observed in the carrageenan test might contribute in reduction of pain response in the second phase of the formalin test.
Collapse
Affiliation(s)
- Valiollah Hajhashemi
- Department of Pharmacology and Isfahan Pharmaceutical Sciences Research Center, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Hossein Sadeghi
- Department of Pharmacology, Faculty of Medicine, Yasuj University of Medical Sciences, Yasuj, Iran
| | - Fatemeh Karimi Madab
- Department of Pharmacology and Isfahan Pharmaceutical Sciences Research Center, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
| |
Collapse
|
2
|
Ma D, Huang Q, Gao X, Ford NC, Guo R, Zhang C, Liu S, He SQ, Raja SN, Guan Y. The Utility of Peripherally Restricted Kappa-Opioid Receptor Agonists for Inhibiting Below-Level Pain After Spinal Cord Injury in Mice. Neuroscience 2023; 527:92-102. [PMID: 37516437 PMCID: PMC10530135 DOI: 10.1016/j.neuroscience.2023.07.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 07/10/2023] [Accepted: 07/15/2023] [Indexed: 07/31/2023]
Abstract
Pain after spinal cord injury (SCI) can be difficult to treat. Drugs that target the opioid receptor (OR) outside the central nervous system (CNS) have gained increasing interest in pain control owing to their low risk of central side effects. Asimadoline and ICI-204448 are believed to be peripherally restricted KOR agonists withlimited access to the CNS. This study examined whether they can attenuate pain hypersensitivity in mice subjected to a contusive T10 SCI. Subcutaneous (s.c.) injection of asimadoline (5, 20 mg/kg) and ICI-204448 (1, 10 mg/kg) inhibited heat hypersensitivity at both doses, but only attenuated mechanical hypersensitivity at the high dose. However, the high-dose asimadoline adversely affected animals' exploratory performance in SCI mice and caused aversion, suggesting CNS drug penetration. In contrast, high-dose ICI-204448 did not impair exploration and remained effective in reducing both mechanical and heat hypersensitivities after SCI. Accordingly, we chose to examine the potential peripheral neuronal mechanism for ICI-204448-induced pain inhibition by conducting in vivo calcium imaging of dorsal root ganglion (DRG) in Pirt-GCaMP6s+/- mice. High-dose ICI-204448 (10 mg/kg, s.c.) attenuated the increased fluorescence intensity of lumbar DRG neurons activated by a noxious pinch (400 g) stimulation in SCI mice. In conclusion, systemic administration of ICI-204448 achieved SCI pain inhibition at doses that did not induce notable side effects and attenuated DRG neuronal excitability which may partly contribute to its pain inhibition. These findings suggest that peripherally restricted KOR agonists may be useful for treating SCI pain, but the therapeutic window must be carefully examined.
Collapse
Affiliation(s)
- Danxu Ma
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA
| | - Qian Huang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA
| | - Xinyan Gao
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA
| | - Neil C Ford
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA
| | - Ruijuan Guo
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA
| | - Chi Zhang
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA
| | - Shuguang Liu
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA
| | - Shao-Qiu He
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA
| | - Srinivasa N Raja
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA
| | - Yun Guan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA; Department of Neurological Surgery, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA.
| |
Collapse
|
3
|
Santino F, Gentilucci L. Design of κ-Opioid Receptor Agonists for the Development of Potential Treatments of Pain with Reduced Side Effects. MOLECULES (BASEL, SWITZERLAND) 2023; 28:molecules28010346. [PMID: 36615540 PMCID: PMC9822356 DOI: 10.3390/molecules28010346] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/13/2022] [Accepted: 12/25/2022] [Indexed: 01/04/2023]
Abstract
The κ-opioid receptor (KOR) has recently emerged as an alternative therapeutic target for the development of pain medications, without deleterious side effects associated with the μ-opioid receptor (MOR). However, modulation of KOR is currently under investigation for the treatment of depression, mood disorders, psychiatric comorbidity, and specific drug addictions. However, KOR agonists also trigger adverse effects including sedation, dysphoria, and hallucinations. In this respect, there is currently much debate on alternative paradigms. Recent effort has been devoted in search of biased ligands capable of selectively activating favorable signaling over signaling associated with unwanted side effects. On the other hand, the use of partial agonists is expected to allow the analgesia to be produced at dosages lower than those required to produce the adverse effects. More empirically, the unwanted central effects can be also avoided by using peripherally restricted agonists. In this review, we discuss the more recent trends in the design of KOR-selective, biased or partial, and finally, peripherally acting agonists. Special emphasis is given on the discussion of the most recent approaches for controlling functional selectivity of KOR-specific ligands.
Collapse
|
4
|
Stefanucci A, Della Valle A, Scioli G, Marinaccio L, Pieretti S, Minosi P, Szucs E, Benyhe S, Masci D, Tanguturi P, Chou K, Barlow D, Houseknecht K, Streicher JM, Mollica A. Discovery of κ Opioid Receptor (KOR)-Selective d-Tetrapeptides with Improved In Vivo Antinociceptive Effect after Peripheral Administration. ACS Med Chem Lett 2022; 13:1707-1714. [PMID: 36385929 PMCID: PMC9661715 DOI: 10.1021/acsmedchemlett.2c00237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 10/13/2022] [Indexed: 11/29/2022] Open
Abstract
Peripherally active tetrapeptides as selective κ opioid receptor (KOR) agonists have been prepared in good overall yields and high purity following solid-phase peptide synthesis via Fmoc protection strategy. Structural modifications at the first and second position of the lead compound FF(d-Nle)R-NH2 (FE200041) were contemplated with aromatic side chains containing d-amino acids, such as (d)-pF-Phe, (d)-mF-Phe, (d)-oF-Phe, which led to highly selective and efficacious KOR agonists endowed with strong antinociceptive activity in vivo following intravenous (i.v.) and subcutaneous (s.c.) administration in the tail flick and formalin tests. These results suggest potential clinical applications in the treatment of neuropathic and inflammatory pain.
Collapse
Affiliation(s)
- Azzurra Stefanucci
- Dipartimento
di Farmacia, Università di Chieti-Pescara
“G. d’Annunzio”, Via dei Vestini 31, 66100 Chieti, Italy
| | - Alice Della Valle
- Dipartimento
di Farmacia, Università di Chieti-Pescara
“G. d’Annunzio”, Via dei Vestini 31, 66100 Chieti, Italy
| | - Giuseppe Scioli
- Dipartimento
di Farmacia, Università di Chieti-Pescara
“G. d’Annunzio”, Via dei Vestini 31, 66100 Chieti, Italy
| | - Lorenza Marinaccio
- Dipartimento
di Farmacia, Università di Chieti-Pescara
“G. d’Annunzio”, Via dei Vestini 31, 66100 Chieti, Italy
| | - Stefano Pieretti
- Istituto
Superiore di Sanità, Centro Nazionale Ricerca e Valutazione Preclinica e Clinica dei farmaci, Viale Regina Elena 299, 00161 Rome, Italy
| | - Paola Minosi
- Istituto
Superiore di Sanità, Centro Nazionale Ricerca e Valutazione Preclinica e Clinica dei farmaci, Viale Regina Elena 299, 00161 Rome, Italy
| | - Edina Szucs
- Institute
of Biochemistry, Biological Research Centre, 6726 Szeged, Hungary
| | - Sandor Benyhe
- Institute
of Biochemistry, Biological Research Centre, 6726 Szeged, Hungary
| | - Domiziana Masci
- Department
of Basic Biotechnological Sciences, Intensivological and Perioperative
Clinics, Catholic University of Sacred Heart, Largo Francesco Vito 1, 00168 Rome, Italy
| | | | - Kerry Chou
- Department
of Pharmacology, College of Medicine, University
of Arizona, Tucson, Arizona 85724, United States
| | - Deborah Barlow
- Department
of Biomedical Sciences, College of Osteopathic Medicine, University of New England, Biddeford, Maine 04005, United States
| | - Karen Houseknecht
- Department
of Biomedical Sciences, College of Osteopathic Medicine, University of New England, Biddeford, Maine 04005, United States
| | - John M. Streicher
- Department
of Pharmacology, College of Medicine, University
of Arizona, Tucson, Arizona 85724, United States
| | - Adriano Mollica
- Dipartimento
di Farmacia, Università di Chieti-Pescara
“G. d’Annunzio”, Via dei Vestini 31, 66100 Chieti, Italy
| |
Collapse
|
5
|
Dalefield ML, Scouller B, Bibi R, Kivell BM. The Kappa Opioid Receptor: A Promising Therapeutic Target for Multiple Pathologies. Front Pharmacol 2022; 13:837671. [PMID: 35795569 PMCID: PMC9251383 DOI: 10.3389/fphar.2022.837671] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 05/20/2022] [Indexed: 11/13/2022] Open
Abstract
Kappa-opioid receptors (KOR) are widely expressed throughout the central nervous system, where they modulate a range of physiological processes depending on their location, including stress, mood, reward, pain, inflammation, and remyelination. However, clinical use of KOR agonists is limited by adverse effects such as dysphoria, aversion, and sedation. Within the drug-development field KOR agonists have been extensively investigated for the treatment of many centrally mediated nociceptive disorders including pruritis and pain. KOR agonists are potential alternatives to mu-opioid receptor (MOR) agonists for the treatment of pain due to their anti-nociceptive effects, lack of abuse potential, and reduced respiratory depressive effects, however, dysphoric side-effects have limited their widespread clinical use. Other diseases for which KOR agonists hold promising therapeutic potential include pruritis, multiple sclerosis, Alzheimer’s disease, inflammatory diseases, gastrointestinal diseases, cancer, and ischemia. This review highlights recent drug-development efforts targeting KOR, including the development of G-protein–biased ligands, mixed opioid agonists, and peripherally restricted ligands to reduce side-effects. We also highlight the current KOR agonists that are in preclinical development or undergoing clinical trials.
Collapse
|
6
|
Weiss N, Zamponi GW. Opioid Receptor Regulation of Neuronal Voltage-Gated Calcium Channels. Cell Mol Neurobiol 2021; 41:839-847. [PMID: 32514826 DOI: 10.1007/s10571-020-00894-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Accepted: 05/29/2020] [Indexed: 12/28/2022]
Abstract
Neuronal voltage-gated calcium channels play a pivotal role in the conversion of electrical signals into calcium entry into nerve endings that is required for the release of neurotransmitters. They are under the control of a number of cellular signaling pathways that serve to fine tune synaptic activities, including G-protein coupled receptors (GPCRs) and the opioid system. Besides modulating channel activity via activation of second messengers, GPCRs also physically associate with calcium channels to regulate their function and expression at the plasma membrane. In this mini review, we discuss the mechanisms by which calcium channels are regulated by classical opioid and nociceptin receptors. We highlight the importance of this regulation in the control of neuronal functions and their implication in the development of disease conditions. Finally, we present recent literature concerning the use of novel μ-opioid receptor/nociceptin receptor modulators and discuss their use as potential drug candidates for the treatment of pain.
Collapse
Affiliation(s)
- Norbert Weiss
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czech Republic
- Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Gerald W Zamponi
- Department of Physiology and Pharmacology, Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada.
| |
Collapse
|
7
|
Yadav VD, Kumar L, Kumari P, Kumar S, Singh M, Siddiqi MI, Yadav PN, Batra S. Synthesis and Assessment of Fused β-Carboline Derivatives as Kappa Opioid Receptor Agonists. ChemMedChem 2021; 16:1917-1926. [PMID: 33599108 DOI: 10.1002/cmdc.202100029] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 02/17/2021] [Indexed: 12/17/2022]
Abstract
The synthesis of 5-formyl-6-aryl-6H-indolo[3,2,1-de][1,5] naphthyridine-2-carboxylates by reaction between 1-formyl-9H-β-carbolines and cinnamaldehydes in the presence of pyrrolidine in water with microwave irradiation is described. Pharmacophoric modification of the formyl group offered several new fused β-carboline derivatives, which were investigated for their κ-opioid receptor (KOR) agonistic activity. Two compounds 4 a and 4 c produced appreciable agonist activity on KOR with EC50 values of 46±19 and 134±9 nM, respectively. Moreover, compound-induced KOR signaling studies suggested both compounds to be extremely G-protein-biased agonists. The analgesic effect of 4 a was validated by the increase in tail flick latency in mice in a time-dependent manner, which was completely blocked by the KOR-selective antagonist norBNI. Moreover, unlike U50488, an unbiased full KOR agonist, 4 a did not induce sedation. The docking of 4 a with the human KOR was studied to rationalize the result.
Collapse
Affiliation(s)
- Veena D Yadav
- Medicinal and Process Chemistry Division, CSIR-Central Drug Research Institute Sector 10, Jankipuram Extension, Sitapur Road, Lucknow, 226031, Uttar Pradesh, India
| | - Lalan Kumar
- Medicinal and Process Chemistry Division, CSIR-Central Drug Research Institute Sector 10, Jankipuram Extension, Sitapur Road, Lucknow, 226031, Uttar Pradesh, India
| | - Poonam Kumari
- Neuroscience and Ageing Biology Division, CSIR-Central Drug Research Institute Sector 10, Jankipuram Extension, Sitapur Road, Lucknow, 226031, Uttar Pradesh, India
| | - Sakesh Kumar
- Neuroscience and Ageing Biology Division, CSIR-Central Drug Research Institute Sector 10, Jankipuram Extension, Sitapur Road, Lucknow, 226031, Uttar Pradesh, India.,Academy of Scientific and Innovative Research, CSIR-Human Resource Development Centre, CSIR-HRDC) Campus Sector 19, Kamla Nehru Nagar, Ghaziabad, 201002, Uttar Pradesh, India
| | - Maninder Singh
- Molecular and Structural Biology Division, CSIR-Central Drug Research Institute Sector 10, Jankipuram Extension, Sitapur Road, Lucknow, 226031, Uttar Pradesh, India
| | - Mohammad I Siddiqi
- Molecular and Structural Biology Division, CSIR-Central Drug Research Institute Sector 10, Jankipuram Extension, Sitapur Road, Lucknow, 226031, Uttar Pradesh, India.,Academy of Scientific and Innovative Research, CSIR-Human Resource Development Centre, CSIR-HRDC) Campus Sector 19, Kamla Nehru Nagar, Ghaziabad, 201002, Uttar Pradesh, India
| | - Prem N Yadav
- Neuroscience and Ageing Biology Division, CSIR-Central Drug Research Institute Sector 10, Jankipuram Extension, Sitapur Road, Lucknow, 226031, Uttar Pradesh, India.,Academy of Scientific and Innovative Research, CSIR-Human Resource Development Centre, CSIR-HRDC) Campus Sector 19, Kamla Nehru Nagar, Ghaziabad, 201002, Uttar Pradesh, India
| | - Sanjay Batra
- Medicinal and Process Chemistry Division, CSIR-Central Drug Research Institute Sector 10, Jankipuram Extension, Sitapur Road, Lucknow, 226031, Uttar Pradesh, India.,Academy of Scientific and Innovative Research, CSIR-Human Resource Development Centre, CSIR-HRDC) Campus Sector 19, Kamla Nehru Nagar, Ghaziabad, 201002, Uttar Pradesh, India
| |
Collapse
|
8
|
Spetea M, Schmidhammer H. Kappa Opioid Receptor Ligands and Pharmacology: Diphenethylamines, a Class of Structurally Distinct, Selective Kappa Opioid Ligands. Handb Exp Pharmacol 2021; 271:163-195. [PMID: 33454858 DOI: 10.1007/164_2020_431] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The kappa opioid receptor (KOR), a G protein-coupled receptor, and its endogenous ligands, the dynorphins, are prominent members of the opioid neuromodulatory system. The endogenous kappa opioid system is expressed in the central and peripheral nervous systems, and has a key role in modulating pain in central and peripheral neuronal circuits and a wide array of physiological functions and neuropsychiatric behaviors (e.g., stress, reward, emotion, motivation, cognition, epileptic seizures, itch, and diuresis). We review the latest advances in pharmacology of the KOR, chemical developments on KOR ligands with advances and challenges, and therapeutic and potential applications of KOR ligands. Diverse discovery strategies of KOR ligands targeting natural, naturally derived, and synthetic compounds with different scaffolds, as small molecules or peptides, with short or long-acting pharmacokinetics, and central or peripheral site of action, are discussed. These research efforts led to ligands with distinct pharmacological properties, as agonists, partial agonists, biased agonists, and antagonists. Differential modulation of KOR signaling represents a promising strategy for developing pharmacotherapies for several human diseases, either by activating (treatment of pain, pruritus, and epilepsy) or blocking (treatment of depression, anxiety, and addiction) the receptor. We focus on the recent chemical and pharmacological advances on diphenethylamines, a new class of structurally distinct, selective KOR ligands. Design strategies and investigations to define structure-activity relationships together with in vivo pharmacology of diphenethylamines as agonists, biased agonists, and antagonists and their potential use as therapeutics are discussed.
Collapse
Affiliation(s)
- Mariana Spetea
- Department of Pharmaceutical Chemistry, Institute of Pharmacy and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria.
| | - Helmut Schmidhammer
- Department of Pharmaceutical Chemistry, Institute of Pharmacy and Center for Molecular Biosciences Innsbruck (CMBI), University of Innsbruck, Innsbruck, Austria
| |
Collapse
|
9
|
Schmidhammer H, Erli F, Guerrieri E, Spetea M. Development of Diphenethylamines as Selective Kappa Opioid Receptor Ligands and Their Pharmacological Activities. Molecules 2020; 25:molecules25215092. [PMID: 33147885 PMCID: PMC7663249 DOI: 10.3390/molecules25215092] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 10/28/2020] [Accepted: 10/30/2020] [Indexed: 02/01/2023] Open
Abstract
Among the opioid receptors, the kappa opioid receptor (KOR) has been gaining substantial attention as a promising molecular target for the treatment of numerous human disorders, including pain, pruritus, affective disorders (i.e., depression and anxiety), drug addiction, and neurological diseases (i.e., epilepsy). Particularly, the knowledge that activation of the KOR, opposite to the mu opioid receptor (MOR), does not produce euphoria or leads to respiratory depression or overdose, has stimulated the interest in discovering ligands targeting the KOR as novel pharmacotherapeutics. However, the KOR mediates the negative side effects of dysphoria/aversion, sedation, and psychotomimesis, with the therapeutic promise of biased agonism (i.e., selective activation of beneficial over deleterious signaling pathways) for designing safer KOR therapeutics without the liabilities of conventional KOR agonists. In this review, the development of new KOR ligands from the class of diphenethylamines is presented. Specifically, we describe the design strategies, synthesis, and pharmacological activities of differently substituted diphenethylamines, where structure–activity relationships have been extensively studied. Ligands with distinct profiles as potent and selective agonists, G protein-biased agonists, and selective antagonists, and their potential use as therapeutic agents (i.e., pain treatment) and research tools are described.
Collapse
MESH Headings
- Analgesics, Opioid/chemistry
- Analgesics, Opioid/therapeutic use
- Humans
- Ligands
- Pain/drug therapy
- Pain/metabolism
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/chemistry
- Receptors, Opioid, kappa/metabolism
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/chemistry
- Receptors, Opioid, mu/metabolism
- Structure-Activity Relationship
Collapse
|