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Huskinson SL, Platt DM, Brasfield M, Follett ME, Prisinzano TE, Blough BE, Freeman KB. Quantification of observable behaviors induced by typical and atypical kappa-opioid receptor agonists in male rhesus monkeys. Psychopharmacology (Berl) 2020; 237:2075-2087. [PMID: 32372348 PMCID: PMC7308209 DOI: 10.1007/s00213-020-05519-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Accepted: 04/01/2020] [Indexed: 12/20/2022]
Abstract
RATIONALE Kappa-opioid receptor (KOR) agonists are antinociceptive but have side effects that limit their therapeutic utility. New KOR agonists have been developed that are fully efficacious at the KOR but may produce fewer or reduced side effects that are typical of KOR agonists. OBJECTIVES We determined behavioral profiles for typical and atypical KOR agonists purported to differ in intracellular-signaling profiles as well as a mu-opioid receptor (MOR) agonist, oxycodone, using a behavioral scoring system based on Novak et al. (Am J Primatol 28:124-138, 1992, Am J Primatol 46:213-227, 1998) and modified to quantify drug-induced effects (e.g., Duke et al. J Pharmacol Exp Ther 366:145-157, 2018). METHODS Six adult male rhesus monkeys were administered a range of doses of the typical KOR agonists, U50-488H (0.0032-0.1 mg/kg) and salvinorin A (0.00032-0.01 mg/kg); the atypical KOR agonists, nalfurafine (0.0001-0.001 mg/kg) and triazole 1.1 (0.01-0.32 mg/kg); the MOR agonist, oxycodone (0.0032-0.32 mg/kg); and as controls, cocaine (0.032-0.32 mg/kg) and ketamine (0.32-10 mg/kg). For time-course determinations, the largest dose of each KOR agonist or MOR agonist was administered across timepoints (10-320 min). In mixture conditions, oxycodone (0.1 mg/kg) was followed by KOR-agonist administration. RESULTS Typical KOR agonists produced sedative-like and motor-impairing effects. Nalfurafine was similar to typical KOR agonists on most outcomes, and triazole 1.1 produced no effects on its own except for reducing scratch during time-course determinations. In the mixture, all KOR agonists reduced oxycodone-induced scratching, U50-488H and nalfurafine reduced species-typical activity, and U50-488H increased rest/sleep posture. CONCLUSIONS Atypical "biased" KOR agonists produce side-effect profiles that are relatively benign (triazole 1.1) or reduced (nalfurafine) compared to typical KOR agonists.
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MESH Headings
- 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer/pharmacology
- Analgesics, Opioid/pharmacology
- Animals
- Behavior, Animal/drug effects
- Behavior, Animal/physiology
- Diterpenes, Clerodane/pharmacology
- Dose-Response Relationship, Drug
- Macaca mulatta
- Male
- Morphinans/pharmacology
- Motor Activity/drug effects
- Motor Activity/physiology
- Oxycodone/pharmacology
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/physiology
- Spiro Compounds/pharmacology
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Affiliation(s)
- S L Huskinson
- Division of Neurobiology and Behavior Research, Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, MS, 39216, USA.
| | - D M Platt
- Division of Neurobiology and Behavior Research, Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, MS, 39216, USA
| | - M Brasfield
- Division of Neurobiology and Behavior Research, Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, MS, 39216, USA
| | - M E Follett
- Division of Neurobiology and Behavior Research, Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, MS, 39216, USA
| | - T E Prisinzano
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY, 40536, USA
| | - B E Blough
- Research Triangle Institute, Research Triangle Park, NC, 27709, USA
| | - K B Freeman
- Division of Neurobiology and Behavior Research, Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, MS, 39216, USA
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2
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Abstract
The organization of estrogenic signaling in the CNS is exceedingly complex. It is comprised of peripherally and centrally synthesized estrogens, and a plethora of types of estrogen receptor that can localize to both the nucleus and the plasma membrane. Moreover, CNS estrogen receptors can exist independent of aromatase (aka estrogen synthase) as well as oligomerize with it, along with a host of other membrane signaling proteins. This ability of CNS estrogen receptors to either to physically pair or exist separately enables locally produced estrogens to act on multiple spatial levels, with a high degree of gradated regulation and plasticity, signaling either in-phase or out-of phase with circulating estrogens. This complexity explains the numerous contradictory findings regarding sex-dependent pain processing and sexually dimorphic opioid antinociception. This review highlights the increasing awareness that estrogens are major endogenous arbiters of both opioid analgesic actions and the mechanisms used to achieve them. This behooves us to understand, and possibly intercede at, the points of intersection of estrogenic signaling and opioid functionality. Factors that integrate estrogenic actions at subcellular, synaptic, and CNS regional levels are likely to be prime drug targets for novel pharmacotherapies designed to modulate CNS estrogen-dependent opioid functionalities and possibly circumvent the current opioid epidemic.
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MESH Headings
- Analgesia
- Analgesics, Opioid/pharmacology
- Animals
- Aromatase
- Brain/physiology
- Dynorphins/physiology
- Estrogens/physiology
- Female
- Humans
- Male
- Neurosecretory Systems/physiology
- Nociception/drug effects
- Nociception/physiology
- Receptors, Estrogen/physiology
- Receptors, Opioid, kappa/drug effects
- Receptors, Opioid, kappa/physiology
- Receptors, Opioid, mu/drug effects
- Receptors, Opioid, mu/physiology
- Reproduction/physiology
- Sex Characteristics
- Signal Transduction/physiology
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Affiliation(s)
- Alan R Gintzler
- Department of Obstetrics and Gynecology, State University of New York, Downstate Medical Center, Brooklyn, NY, United States.
| | - Emiliya M Storman
- Department of Obstetrics and Gynecology, State University of New York, Downstate Medical Center, Brooklyn, NY, United States
| | - Nai-Jiang Liu
- Department of Obstetrics and Gynecology, State University of New York, Downstate Medical Center, Brooklyn, NY, United States
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Jacobs BA, Pando MM, Jennings E, Chavera TA, Clarke WP, Berg KA. Allosterism within δ Opioid- κ Opioid Receptor Heteromers in Peripheral Sensory Neurons: Regulation of κ Opioid Agonist Efficacy. Mol Pharmacol 2018; 93:376-386. [PMID: 29436492 PMCID: PMC5832326 DOI: 10.1124/mol.117.109975] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 02/01/2018] [Indexed: 11/22/2022] Open
Abstract
There is abundant evidence for formation of G protein-coupled receptor heteromers in heterologous expression systems, but little is known of the function of heteromers in native systems. Heteromers of δ and κ opioid receptors (DOR-KOR heteromers) have been identified in native systems. We previously reported that activation of DOR-KOR heteromers expressed by rat pain-sensing neurons (nociceptors) produces robust, peripherally mediated antinociception. Moreover, DOR agonist potency and efficacy is regulated by KOR antagonists via allosteric interactions within the DOR-KOR heteromer in a ligand-dependent manner. Here we assessed the reciprocal regulation of KOR agonist function by DOR antagonists in adult rat nociceptors in culture and in a behavioral assay of nociception. Naltrindole enhanced the potency of the KOR agonist 2-(3,4-dichlorophenyl)-N-methyl-N-[(1S)-1-phenyl-2-pyrrolidin-1-ylethyl]acetamide (ICI-199441) 10- to 20-fold, but did not alter responses to 2-(3,4-dichlorophenyl)-N-methyl-N-[(1R,2R)-2-pyrrolidin-1-ylcyclohexyl]acetamide (U50488). By contrast, the potency of U50488 was enhanced 20-fold by 7-benzylidenenaltrexone. The efficacy of 6'-guanidinonaltrindole (6'-GNTI) to inhibit nociceptors was blocked by small interfering RNA knockdown of DOR or KOR. Replacing 6'-GNTI occupancy of DOR with either naltrindole or 7-benzylidenenaltrexone abolished 6'-GNTI efficacy. Further, peptides derived from DOR transmembrane segment 1 fused to the cell membrane-penetrating HIV transactivator of transcription peptide also blocked 6'-GNTI-mediated responses ex vivo and in vivo, suggesting that 6'-GNTI efficacy in nociceptors is due to its positive allosteric regulation of KOR via occupancy of DOR in a DOR-KOR heteromer. Together, these results provide evidence for the existence of functional DOR-KOR heteromers in rat peripheral sensory neurons and that reciprocal, ligand-dependent allosteric interactions occur between the DOR and KOR protomers.
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MESH Headings
- Allosteric Regulation/drug effects
- Allosteric Regulation/physiology
- Amino Acid Sequence
- Analgesics, Opioid/pharmacology
- Animals
- Cells, Cultured
- Dose-Response Relationship, Drug
- Male
- Peptide Fragments/genetics
- Peptide Fragments/pharmacology
- Peripheral Nerves/drug effects
- Peripheral Nerves/physiology
- Rats
- Rats, Sprague-Dawley
- Receptors, Opioid, delta/agonists
- Receptors, Opioid, delta/physiology
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/physiology
- Sensory Receptor Cells/drug effects
- Sensory Receptor Cells/physiology
- Trigeminal Ganglion/drug effects
- Trigeminal Ganglion/physiology
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Affiliation(s)
- Blaine A Jacobs
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Miryam M Pando
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Elaine Jennings
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Teresa A Chavera
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - William P Clarke
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Kelly A Berg
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
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Lê AD, Funk D, Coen K, Tamadon S, Shaham Y. Role of κ-Opioid Receptors in the Bed Nucleus of Stria Terminalis in Reinstatement of Alcohol Seeking. Neuropsychopharmacology 2018; 43:838-850. [PMID: 28589966 PMCID: PMC5809779 DOI: 10.1038/npp.2017.120] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Revised: 05/31/2017] [Accepted: 06/01/2017] [Indexed: 12/21/2022]
Abstract
κ-Opioid receptors (KORs) and their endogenous ligand dynorphin are involved in stress-induced alcohol seeking but the mechanisms involved are largely unknown. We previously showed that systemic injections of the KOR agonist U50,488, which induce stress-like aversive states, reinstate alcohol seeking after extinction of the alcohol-reinforced responding. Here, we used the neuronal activity marker Fos and site-specific injections of the KOR antagonist nor-BNI and U50,488 to study brain mechanisms of U50,488-induced reinstatement of alcohol seeking. We trained male Long-Evans rats to self-administer alcohol (12% w/v) for 23-30 days. After extinction of the alcohol-reinforced responding, we tested the effect of U50,488 (0, 1.25, 2.5, and 5 mg/kg) on reinstatement of alcohol seeking. Next, we correlated regional Fos expression with reinstatement induced by the most effective U50,488 dose (5 mg/kg). Based on the correlational Fos results, we determined the effect of bed nucleus of the stria terminalis (BNST) injections of nor-BNI (4 μg/side) on U50,488-induced reinstatement of alcohol seeking, and reinstatement induced by injections of U50,488 (0, 0.3, 1, and 3 μg/side) into the BNST. U50,488-induced reinstatement of alcohol seeking was associated with increased Fos expression in multiple brain areas, including the BNST, where it was significantly correlated with lever pressing. U50,488-induced reinstatement was blocked by BNST nor-BNI injections, and BNST U50,488 injections partially mimicked the drug's systemic effect on reinstatement. Our data indicate that the BNST is a critical site for U50,488-induced reinstatement of alcohol seeking and suggest that KOR/dynorphin mechanisms in this brain area play a key role in stress-induced alcohol seeking.
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Affiliation(s)
- A D Lê
- Neurobiology of Alcohol Laboratory, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Douglas Funk
- Neurobiology of Alcohol Laboratory, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Kathleen Coen
- Neurobiology of Alcohol Laboratory, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Sahar Tamadon
- Neurobiology of Alcohol Laboratory, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Yavin Shaham
- Behavioral Neuroscience Branch, Intramural Research Program, NIDA-NIH, Baltimore, MD, USA
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5
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Geng X, Zhao H, Zhang S, Li J, Tian F, Feng N, Fan R, Jia M, Guo H, Cheng L, Liu J, Chen W, Pei J. κ-opioid receptor is involved in the cardioprotection induced by exercise training. PLoS One 2017; 12:e0170463. [PMID: 28301473 PMCID: PMC5354247 DOI: 10.1371/journal.pone.0170463] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 02/27/2017] [Indexed: 02/02/2023] Open
Abstract
The present study was designed to test the hypothesis that exercise training elicited a cardioprotective effect against ischemia and reperfusion (I/R) via the κ-opioid receptor (κ-OR)-mediated signaling pathway. Rats were randomly divided into four groups: the control group, the moderate intensity exercise (ME) group, the high intensity exercise (HE) group, and the acute exercise (AE) group. For the exercise training protocols, the rats were subjected to one week of adaptive treadmill training, while from the second week, the ME and HE groups were subjected to eight weeks of exercise training, and the AE group was subjected to three days of adaptive treadmill training and one day of vigorous exercise. After these protocols, the three exercise training groups were divided into different treatment groups, and the rats were subjected to 30 min of ischemia and 120 min of reperfusion. Changes in infarct size and serum cTnT (cardiac troponin T) caused by I/R were reduced by exercise training. Moreover, cardiac dysfunction caused by I/R was also alleviated by exercise training. These effects of exercise training were reversed by nor-BNI (a selective κ-OR antagonist), Compound C (a selective AMPK inhibitor), Akt inhibitor and L-NAME (a non-selective eNOS inhibitor). Expression of κ-OR and phosphorylation of AMPK, Akt and eNOS were significantly increased in the ME, HE and AE groups. These findings demonstrated that the cardioprotective effect of exercise training is possibly mediated by the κ-OR-AMPK-Akt-eNOS signaling pathway.
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Affiliation(s)
- Xiao Geng
- Department of Physiology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi’an, Shaanxi Province, People’s Republic of China
- Department of Physical Education, Chang’an University, Xi'an, Shaanxi Province, China
| | - Honglin Zhao
- Department of Cardiovascular Surgery, First Hospital of Lanzhou University, Lanzhou, Gansu Province, China
| | - Shumiao Zhang
- Department of Physiology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi’an, Shaanxi Province, People’s Republic of China
| | - Juan Li
- Department of Physiology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi’an, Shaanxi Province, People’s Republic of China
| | - Fei Tian
- Department of Physiology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi’an, Shaanxi Province, People’s Republic of China
| | - Na Feng
- Department of Physiology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi’an, Shaanxi Province, People’s Republic of China
| | - Rong Fan
- Department of Physiology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi’an, Shaanxi Province, People’s Republic of China
| | - Min Jia
- Department of Physiology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi’an, Shaanxi Province, People’s Republic of China
| | - Haitao Guo
- Department of Physiology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi’an, Shaanxi Province, People’s Republic of China
| | - Liang Cheng
- Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi Province, China
| | - Jincheng Liu
- Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi Province, China
| | - Wensheng Chen
- Department of Cardiovascular Surgery, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi Province, China
- * E-mail: (JP); (W C)
| | - Jianming Pei
- Department of Physiology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi’an, Shaanxi Province, People’s Republic of China
- * E-mail: (JP); (W C)
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6
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Loh R, Chau L, Aijaz A, Wu K, Galvez R. Antagonizing the different stages of kappa opioid receptor activation selectively and independently attenuates acquisition and consolidation of associative memories. Behav Brain Res 2017; 323:1-10. [PMID: 28119127 DOI: 10.1016/j.bbr.2017.01.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 01/11/2017] [Accepted: 01/18/2017] [Indexed: 01/04/2023]
Abstract
Previous work from our laboratory has shown that nonspecific kappa opioid receptor (KOR) antagonism in primary somatosensory cortex (S1) can inhibit acquisition for the forebrain-dependent associative task, Whisker-Trace Eyeblink conditioning (WTEB). Although studies have demonstrated that KOR activation can alter stimuli salience, our studies controlled for these factors, demonstrating that KOR also plays a role in facilitating learning. KOR has two distinct phases of activation followed by internalization/downregulation, that each independently activate kinases and transcription factors known to mediate task acquisition and memory consolidation respectively. The current study demonstrated that antagonism of the initial phase of KOR activation in S1 via local injections of the g-protein inhibitor, pertussis toxin (PTX), blocked initial WTEB acquisition without affecting retention of the association. In contrast, KOR late phase antagonism in S1 via local injections of the GRK3-specific antagonist, guanidinonaltrindole (GNTI), blocked retention of the WTEB association without affecting task acquisition. Consistent with the known mechanism for KOR activation, KOR protein expression in S1 was found to be decreased following WTEB training, further supporting the involvement of neocortical KOR activation with learning. Prior studies have shown that task acquisition and memory consolidation are mediated by distinct molecular processes; however, little is known regarding a potential mechanism driving these processes. The current study suggests that neocortical KOR activation mediates activation of these processes with learning. This study provides the first evidence for a time- and learning-dependent property of neocortical KOR in facilitating acquisition and consolidation of associative memories, while elucidating an unexplored neocortical learning mechanism.
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Affiliation(s)
- Ryan Loh
- Psychology Department, University of Illinois at Urbana-Champaign, 405 N. Mathews Ave., Urbana, IL 61801, USA; Neuroscience Program, University of Illinois at Urbana-Champaign, 405 N. Mathews Ave., Urbana, IL 61801, USA.
| | - Lily Chau
- Psychology Department, University of Illinois at Urbana-Champaign, 405 N. Mathews Ave., Urbana, IL 61801, USA; Neuroscience Program, University of Illinois at Urbana-Champaign, 405 N. Mathews Ave., Urbana, IL 61801, USA.
| | - Ali Aijaz
- Neuroscience Program, University of Illinois at Urbana-Champaign, 405 N. Mathews Ave., Urbana, IL 61801, USA.
| | - Kevin Wu
- Neuroscience Program, University of Illinois at Urbana-Champaign, 405 N. Mathews Ave., Urbana, IL 61801, USA.
| | - Roberto Galvez
- Psychology Department, University of Illinois at Urbana-Champaign, 405 N. Mathews Ave., Urbana, IL 61801, USA; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, 405 N. Mathews Ave., Urbana, IL 61801, USA; Neuroscience Program, University of Illinois at Urbana-Champaign, 405 N. Mathews Ave., Urbana, IL 61801, USA.
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7
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Robinson DL, Nag S, Mokha SS. Estrogen facilitates and the kappa and mu opioid receptors mediate antinociception produced by intrathecal (-)-pentazocine in female rats. Behav Brain Res 2016; 312:163-8. [PMID: 27312267 DOI: 10.1016/j.bbr.2016.06.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 06/09/2016] [Accepted: 06/10/2016] [Indexed: 01/01/2023]
Abstract
Pentazocine, a mixed-action kappa opioid receptor (KOR) agonist, has high affinity for both KOR and the mu opioid receptor (MOR), and has been shown clinically to alleviate pain with a pronounced effect in women. However, whether local application of pentazocine in the spinal cord produces antinociception and the contribution of spinal KOR and MOR in mediating the effect of pentazocine in female rats remain unknown. Also, it is not known whether pentazocine-induced antinociception in females is estrogen-dependent. Hence, we investigated whether intrathecal (i.t.) (-)-pentazocine produces thermal antinociception and whether estrogen modulates the drug effect in female rats. Only the highest dose of pentazocine (500 nmol) was effective in producing antinociception in ovariectomized (OVX) rats. In contrast, pentazocine produced antinociception in estradiol-treated ovariectomized females (OVX+E) rats with the lowest effective dose being 250nmol. KOR or MOR mediated the effect of the lowest effective dose in OVX+E rats; however, MOR blockade extended the KOR-mediated effect of 500nmol pentazocine in both groups. In normally cycling females, the 250nmol dose was effective in producing antinociception at the proestrous, but not at the diestrous stage of the estrous cycle. Thus, estrogen facilitates and KOR or MOR mediates. the antinociceptive effect of i.t. (-)-pentazocine in female rats. Selective doses of (-)-pentazocine, with or without MOR blockade, may have a therapeutic benefit.
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MESH Headings
- Analgesics/administration & dosage
- Animals
- Estradiol/administration & dosage
- Estrogen Antagonists/administration & dosage
- Estrous Cycle
- Female
- Hot Temperature
- Injections, Spinal
- Nociception/drug effects
- Ovariectomy
- Pain Measurement
- Pain Threshold/drug effects
- Pentazocine/administration & dosage
- Rats
- Rats, Sprague-Dawley
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/physiology
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/physiology
- Spinal Cord/drug effects
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Affiliation(s)
- Douglas L Robinson
- Department of Neuroscience and Pharmacology, Meharry Medical College, Nashville, TN 37208, USA
| | - Subodh Nag
- Department of Neuroscience and Pharmacology, Meharry Medical College, Nashville, TN 37208, USA
| | - Sukhbir S Mokha
- Department of Neuroscience and Pharmacology, Meharry Medical College, Nashville, TN 37208, USA.
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Macedo CG, Fanton LE, Fischer L, Tambeli CH. Coactivation of μ- and κ-Opioid Receptors May Mediate the Protective Effect of Testosterone on the Development of Temporomandibular Joint Nociception in Male Rats. J Oral Facial Pain Headache 2016; 30:61-7. [PMID: 26817034 DOI: 10.11607/ofph.1298] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
AIMS To investigate whether the protective effect of testosterone on the development of temporomandibular joint (TMJ) nociception in male rats is mediated by the activation of central opioid mechanisms. METHODS Experiments were performed on 156 male Wistar rats. A pharmacologic approach was used to assess the ability of opioid receptor antagonists infused into the dorsal portion of the brainstem and adjacent to the caudal component (subnucleus caudalis) of the spinal trigeminal nucleus to block the protective effect of testosterone in male rats. The TMJ injection of 0.5% formalin was used as a nociceptive stimulus. One-way or two-way ANOVA was used for data analyses. RESULTS The injection of 0.5% formalin into the TMJ induced a significant nociceptive behavior in gonadectomized male rats (P < .05), but not in naïve, sham, and testosterone-replaced gonadectomized rats, confirming that testosterone prevents the development of TMJ nociception. The injection of either the nonselective opioid receptor antagonist naloxone (15 μg) or the simultaneous injection of the μ-opioid receptor antagonist Cys2, Tyr3, Orn5, Pen7amide (CTOP, 30 μg) and the κ-opioid receptor antagonist Nor-Binaltorphimine (Nor-BNI, 90 μg) significantly increased the 0.5% formalin-induced behavioral response in sham and testosterone-replaced gonadectomized rats (P < .05) but had no effect in gonadectomized rats. However, the injection of each selective opioid receptor antagonist alone or the simultaneous injection of μ- or κ- and δ-opioid receptor antagonists had no effect. CONCLUSION These findings indicate that the protective effect of endogenous testosterone on the development of TMJ nociception in male rats is mediated by the activation of central opioid mechanisms. Furthermore, the coactivation of central μ- and κ-opioid receptors is necessary for testosterone to protect male rats from developing TMJ nociception.
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9
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Affiliation(s)
- Charles Chavkin
- Neuroscience Graduate Program and Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington.
| | - Jonathan M Ehrich
- Neuroscience Graduate Program and Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington
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10
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Polter AM, Bishop RA, Briand LA, Graziane NM, Pierce RC, Kauer JA. Poststress block of kappa opioid receptors rescues long-term potentiation of inhibitory synapses and prevents reinstatement of cocaine seeking. Biol Psychiatry 2014; 76:785-93. [PMID: 24957331 PMCID: PMC4240751 DOI: 10.1016/j.biopsych.2014.04.019] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 04/16/2014] [Accepted: 04/17/2014] [Indexed: 11/18/2022]
Abstract
BACKGROUND Dopaminergic neurons in the ventral tegmental area of the brain are an important site of convergence of drugs and stress. We previously identified a form of long-term potentiation of gamma-aminobutyric acid (GABA)ergic synapses on these neurons (LTPGABA). Our studies have shown that exposure to acute stress blocks this LTP and that reversal of the block of LTPGABA is correlated with prevention of stress-induced reinstatement of cocaine-seeking behavior. METHODS Sprague-Dawley rats were subjected to cold-water swim stress. Midbrain slices were prepared following stress, and whole-cell patch clamp recordings of inhibitory postsynaptic currents were performed from ventral tegmental area dopamine neurons. Antagonists of glucocorticoid receptors and kappa opioid receptors (κORs) were administered at varying time points after stress. Additionally, the ability of a kappa antagonist administered following stress to block forced swim stress-induced reinstatement of cocaine self-administration was tested. RESULTS We found that an acute stressor blocks LTPGABA for 5 days after stress through a transient activation of glucocorticoid receptors and more lasting contribution of κORs. Even pharmacological block of κORs beginning 4 days after stress has occurred reversed the block of LTPGABA. Administration of a κORs antagonist following stress prevents reinstatement of cocaine-seeking behavior. CONCLUSIONS A brief stressor produces changes in the reward circuitry lasting several days. Our findings reveal roles for glucocorticoid receptors and κORs as mediators of the lasting effects of stress on synaptic plasticity. κORs antagonists reverse the neuroadaptations underlying stress-induced drug-seeking behavior and may be useful in the treatment of cocaine addiction.
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Affiliation(s)
- Abigail M Polter
- Department of Molecular Pharmacology, Physiology and Biotechnology, Brown University, Providence, Rhode Island
| | - Rachel A Bishop
- Department of Molecular Pharmacology, Physiology and Biotechnology, Brown University, Providence, Rhode Island
| | - Lisa A Briand
- Center for Neurobiology and Behavior, Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Nicholas M Graziane
- Department of Molecular Pharmacology, Physiology and Biotechnology, Brown University, Providence, Rhode Island
| | - R Christopher Pierce
- Center for Neurobiology and Behavior, Department of Psychiatry, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania
| | - Julie A Kauer
- Department of Molecular Pharmacology, Physiology and Biotechnology, Brown University, Providence, Rhode Island.
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11
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Cai W, Zhang Y, Li J, Wang J. [κ-opioid receptor agonist U50, 488H attenuates myocardial ischemia-reperfusionvia modulating Toll-like receptor 4/nuclear factor-κB signaling in rat]. Zhonghua Xin Xue Guan Bing Za Zhi 2014; 42:866-872. [PMID: 25547452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
OBJECTIVE To observe the effects of κ-opioid receptor agonist U50, 488H on myocardial ischemia and reperfusion injury and related mechanism. METHODS Rats were randomly divided into sham operation, myocardial ischemia and reperfusion(I/R, 30 min ischemia followed by 120 min reperfusion), and MI/R+U50, 488H (1.5 mg/kg) and I/R+U50, 488H+ selective κ-opioid receptor antagonist Nor-BNI (2 mg/kg, n = 8 each). The infarction size and the incidence of ventricular arrhythmias were observed.Real-time PCR and DAB staining were used to define the myocardium Toll-like receptor 4(TLR4) expression. Myeloperoxidase level, TNF-α induction and the expression of NF-κB were also examined in rats. RESULTS After I/R, the expressions of myocardial TLR4 and NF-κB increased significantly both in ischemia area and area at risk. Compared with I/R, κ-opioid receptor stimulation with U50, 488H significantly attenuated the expressions of TLR4 and NF-κB and reduced myeloperoxidase (MPO) levels, myocardial TNF-α production, myocardial infarct sizes and the incidence of ventricular arrhythmias and arrhythmia score (2.9 ± 0.7 vs. 4.4 ± 0.9, P < 0.05) , above effects of U50, 488H were partly abolished by co-treatment with Nor-BNI. CONCLUSION These data provide evidence for the first time that κ-opioid receptor stimulation could attenuate myocardial I/R injury via downregulating TLR4/NF-κB signaling in rats.
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Affiliation(s)
| | - Yan Zhang
- Department of Cardiovascular Surgery, Kunming General Hospital of Chengdu Military Region of People's Liberation Army, Chengdu 650032, China
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12
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Schindler AG, Messinger DI, Smith JS, Shankar H, Gustin RM, Schattauer SS, Lemos JC, Chavkin NW, Hagan CE, Neumaier JF, Chavkin C. Stress produces aversion and potentiates cocaine reward by releasing endogenous dynorphins in the ventral striatum to locally stimulate serotonin reuptake. J Neurosci 2012; 32:17582-96. [PMID: 23223282 PMCID: PMC3523715 DOI: 10.1523/jneurosci.3220-12.2012] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2012] [Revised: 10/02/2012] [Accepted: 10/09/2012] [Indexed: 01/23/2023] Open
Abstract
Activation of the dynorphin/κ-opioid receptor (KOR) system by repeated stress exposure or agonist treatment produces place aversion, social avoidance, and reinstatement of extinguished cocaine place preference behaviors by stimulation of p38α MAPK, which subsequently causes the translocation of the serotonin transporter (SERT, SLC6A4) to the synaptic terminals of serotonergic neurons. In the present study we extend those findings by showing that stress-induced potentiation of cocaine conditioned place preference occurred by a similar mechanism. In addition, SERT knock-out mice did not show KOR-mediated aversion, and selective reexpression of SERT by lentiviral injection into the dorsal raphe restored the prodepressive effects of KOR activation. Kinetic analysis of several neurotransporters demonstrated that repeated swim stress exposure selectively increased the V(max) but not K(m) of SERT without affecting dopamine transport or the high-capacity, low-affinity transporters. Although the serotonergic neurons in the dorsal raphe project throughout the forebrain, a significant stress-induced increase in cell-surface SERT expression was only evident in the ventral striatum, and not in the dorsal striatum, hippocampus, prefrontal cortex, amygdala, or dorsal raphe. Stereotaxic microinjections of the long-lasting KOR antagonist norbinaltorphimine demonstrated that local KOR activation in the nucleus accumbens, but not dorsal raphe, mediated this stress-induced increase in ventral striatal surface SERT expression. Together, these results support the hypothesis that stress-induced activation of the dynorphin/KOR system produces a transient increase in serotonin transport locally in the ventral striatum that may underlie some of the adverse consequences of stress exposure, including the potentiation of the rewarding effects of cocaine.
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Affiliation(s)
- Abigail G. Schindler
- Department of Pharmacology, University of Washington, School of Medicine, Seattle, Washington 98195, and
| | - Daniel I. Messinger
- Department of Pharmacology, University of Washington, School of Medicine, Seattle, Washington 98195, and
| | - Jeffrey S. Smith
- Department of Pharmacology, University of Washington, School of Medicine, Seattle, Washington 98195, and
| | - Haripriya Shankar
- Department of Pharmacology, University of Washington, School of Medicine, Seattle, Washington 98195, and
| | - Richard M. Gustin
- Department of Pharmacology, University of Washington, School of Medicine, Seattle, Washington 98195, and
| | - Selena S. Schattauer
- Department of Pharmacology, University of Washington, School of Medicine, Seattle, Washington 98195, and
| | - Julia C. Lemos
- Department of Pharmacology, University of Washington, School of Medicine, Seattle, Washington 98195, and
- Graduate Program in Neurobiology and Behavior and
| | - Nicholas W. Chavkin
- Department of Pharmacology, University of Washington, School of Medicine, Seattle, Washington 98195, and
| | | | - John F. Neumaier
- Graduate Program in Neurobiology and Behavior and
- Psychiatry and Behavioral Sciences, School of Medicine, University of Washington, Seattle, Washington 98195
| | - Charles Chavkin
- Department of Pharmacology, University of Washington, School of Medicine, Seattle, Washington 98195, and
- Graduate Program in Neurobiology and Behavior and
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13
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Butelman ER, Yuferov V, Kreek MJ. κ-opioid receptor/dynorphin system: genetic and pharmacotherapeutic implications for addiction. Trends Neurosci 2012; 35:587-96. [PMID: 22709632 DOI: 10.1016/j.tins.2012.05.005] [Citation(s) in RCA: 140] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Revised: 04/27/2012] [Accepted: 05/17/2012] [Indexed: 11/17/2022]
Abstract
Addictions to cocaine or heroin/prescription opioids [short-acting μ-opioid receptor (MOPr) agonists] involve relapsing cycles, with experimentation/escalating use, withdrawal/abstinence, and relapse/re-escalation. κ-Opioid receptors (KOPr; encoded by OPRK1), and their endogenous agonists, the dynorphins (encoded by PDYN), have counter-modulatory effects on reward caused by cocaine or MOPr agonist exposure, and exhibit plasticity in addictive-like states. KOPr/dynorphin activation is implicated in depression/anxiety, often comorbid with addictions. In this opinion article we propose that particular stages of the addiction cycle are differentially affected by KOPr/dynorphin systems. Vulnerability and resilience can be due to pre-existing (e.g., genetic) factors, or epigenetic modifications of the OPRK1 or PDYN genes during the addiction cycle. Pharmacotherapeutic approaches limiting changes in KOPr/dynorphin tone, especially with KOPr partial agonists, may hold potential for the treatment of specific drug addictions and psychiatric comorbidity.
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MESH Headings
- Adaptation, Biological/genetics
- Adaptation, Biological/physiology
- Animals
- Behavior, Addictive/drug therapy
- Behavior, Addictive/genetics
- Behavior, Addictive/physiopathology
- Disease Models, Animal
- Drug Discovery/methods
- Dynorphins/physiology
- Enkephalins/genetics
- Genetic Predisposition to Disease/genetics
- Humans
- Illicit Drugs/pharmacology
- Narcotic Antagonists/pharmacology
- Narcotic Antagonists/therapeutic use
- Polymorphism, Genetic
- Protein Precursors/genetics
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/antagonists & inhibitors
- Receptors, Opioid, kappa/physiology
- Recurrence
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Affiliation(s)
- Eduardo R Butelman
- Laboratory of the Biology of Addictive Diseases, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA
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14
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McMullen AB, Baidwan GS, McCarthy KD. Morphological and behavioral changes in the pathogenesis of a novel mouse model of communicating hydrocephalus. PLoS One 2012; 7:e30159. [PMID: 22291910 PMCID: PMC3265463 DOI: 10.1371/journal.pone.0030159] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Accepted: 12/14/2011] [Indexed: 11/18/2022] Open
Abstract
The Ro1 model of hydrocephalus represents an excellent model for studying the pathogenesis of hydrocephalus due to its complete penetrance and inducibility, enabling the investigation of the earliest cellular and histological changes in hydrocephalus prior to overt pathology. Hematoxylin and eosin staining, immunofluorescence and electron microscopy were used to characterize the histopathological events of hydrocephalus in this model. Additionally, a broad battery of behavioral tests was used to investigate behavioral changes in the Ro1 model of hydrocephalus. The earliest histological changes observed in this model were ventriculomegaly and disorganization of the ependymal lining of the aqueduct of Sylvius, which occurred concomitantly. Ventriculomegaly led to thinning of the ependyma, which was associated with periventricular edema and areas of the ventricular wall void of cilia and microvilli. Ependymal denudation was subsequent to severe ventriculomegaly, suggesting that it is an effect, rather than a cause, of hydrocephalus in the Ro1 model. Additionally, there was no closure of the aqueduct of Sylvius or any blockages within the ventricular system, even with severe ventriculomegaly, suggesting that the Ro1 model represents a model of communicating hydrocephalus. Interestingly, even with severe ventriculomegaly, there were no behavioral changes, suggesting that the brain is able to compensate for the structural changes that occur in the pathogenesis of hydrocephalus if the disorder progresses at a sufficiently slow rate.
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MESH Headings
- Animals
- Behavior, Animal/physiology
- Brain/pathology
- Brain/physiopathology
- Brain/ultrastructure
- Cardiomegaly/pathology
- Cerebral Aqueduct/pathology
- Cerebral Aqueduct/ultrastructure
- Cerebral Ventricles/pathology
- Cerebral Ventricles/ultrastructure
- Disease Models, Animal
- Hydrocephalus/complications
- Hydrocephalus/genetics
- Hydrocephalus/pathology
- Hydrocephalus/physiopathology
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Microscopy, Electron
- Receptors, Opioid, kappa/genetics
- Receptors, Opioid, kappa/metabolism
- Receptors, Opioid, kappa/physiology
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Affiliation(s)
- Allison B. McMullen
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Gurlal S. Baidwan
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Ken D. McCarthy
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- * E-mail:
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15
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Kinsey-Jones JS, Grachev P, Li XF, Lin YS, Milligan SR, Lightman SL, O'Byrne KT. The inhibitory effects of neurokinin B on GnRH pulse generator frequency in the female rat. Endocrinology 2012; 153:307-15. [PMID: 22109887 DOI: 10.1210/en.2011-1641] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Neurokinin B (NKB) and its receptor (neurokinin-3 receptor) are coexpressed with kisspeptin and dynorphin A (Dyn) within neurons of the hypothalamic arcuate nucleus, the suggested site of the GnRH pulse generator. It is thought that these neuropeptides interact to regulate gonadotropin secretion. Using the ovariectomized (OVX) and OVX 17β-estradiol-replaced rat models, we have carried out a series of in vivo neuropharmacological and electrophysiological experiments to elucidate the hierarchy between the kisspeptin, NKB, and Dyn signaling systems. Rats were implanted with intracerebroventricular cannulae and cardiac catheters for frequent (every 5 min) automated serial blood sampling. Freely moving rats were bled for 6 h, with intracerebroventricular injections taking place after a 2-h control bleeding period. A further group of OVX rats was implanted with intra-arcuate electrodes for the recording of multiunit activity volleys, which coincide invariably with LH pulses. Intracerebroventricular administration of the selective neurokinin-3 receptor agonist, senktide (100-600 pmol), caused a dose-dependent suppression of LH pulses and multiunit activity volleys. The effects of senktide did not differ between OVX and 17β-estradiol-replaced OVX animals. Pretreatment with a selective Dyn receptor (κ opioid receptor) antagonist, norbinaltorphimine (6.8 nmol), blocked the senktide-induced inhibition of pulsatile LH secretion. Intracerebroventricular injection of senktide did not affect the rise in LH concentrations after administration of kisspeptin (1 nmol), and neither did kisspeptin preclude the senktide-induced suppression of LH pulses. These data show that NKB suppresses the frequency of the GnRH pulse generator in a Dyn/κ opioid receptor-dependent fashion.
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MESH Headings
- Animals
- Arcuate Nucleus of Hypothalamus/drug effects
- Arcuate Nucleus of Hypothalamus/metabolism
- Arcuate Nucleus of Hypothalamus/physiology
- Dynorphins/physiology
- Female
- Gonadotropin-Releasing Hormone/metabolism
- Kisspeptins/pharmacology
- Kisspeptins/physiology
- Luteinizing Hormone/metabolism
- Narcotic Antagonists
- Neurokinin B/pharmacology
- Neurokinin B/physiology
- Ovariectomy
- Peptide Fragments/pharmacology
- Rats
- Rats, Sprague-Dawley
- Receptors, G-Protein-Coupled/agonists
- Receptors, G-Protein-Coupled/physiology
- Receptors, Kisspeptin-1
- Receptors, Neurokinin-3/agonists
- Receptors, Neurokinin-3/physiology
- Receptors, Opioid/physiology
- Receptors, Opioid, kappa/antagonists & inhibitors
- Receptors, Opioid, kappa/physiology
- Signal Transduction
- Substance P/analogs & derivatives
- Substance P/pharmacology
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Affiliation(s)
- James S Kinsey-Jones
- Division of Women's Health, School of Medicine, King's College London, Guy's Campus, London SE1 1UL, United Kingdom
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16
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Lockie SH, Czyzyk TA, Chaudhary N, Perez-Tilve D, Woods SC, Oldfield BJ, Statnick MA, Tschöp MH. CNS opioid signaling separates cannabinoid receptor 1-mediated effects on body weight and mood-related behavior in mice. Endocrinology 2011; 152:3661-7. [PMID: 21810947 DOI: 10.1210/en.2011-1220] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Existing monotherapies for the treatment of obesity provide only modest weight loss and/or have adverse side effects, and this is also the case with the cannabinoid receptor 1 (CB1) inverse agonist, rimonabant. We aimed to investigate the possibility of improving efficacy and reducing side effects of rimonabant by cotreatment with opioid system antagonists. Using both genetic and pharmacological removal of opioid signaling in mice, we investigated changes in body weight, food intake, and fat mass as well as behavioral outcomes of interactions between opioid ligands and the CB1 using the inverse agonist, rimonabant. The ability of rimonabant to reduce weight is enhanced by removal of with μ-opioid receptor signaling, while not being greatly affected by κ-opioid receptor blockade. Additionally, lack of opioid signaling, especially κ-opioid receptor, attenuated the ability of rimonabant to decrease immobility time in the Porsolt forced-swim test, a preclinical model of depression. These results indicate that the endogenous opioid system is involved in modulating both the metabolic and mood effects of rimonabant.
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Affiliation(s)
- Sarah Haas Lockie
- Metabolic Diseases Institute, University of Cincinnati, Cincinnati, Ohio 45237, USA
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17
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Affiliation(s)
- Stuart Maudsley
- Intramural Research Program/National Institute on Aging/National Institutes of Health, Baltimore, Maryland 21224, USA
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18
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Abstract
There is a vast amount of pharmacological evidence favouring the existence of multiple subtypes of opioid receptors. In addition to the primary classification of µ (mu: MOP), δ (delta: DOP), κ (kappa: KOP) receptors, and the nociceptin/orphanin FQ peptide receptor (NOP), various groups have further classified the pharmacological µ into µ(1-3), the δ into δ(1-2)/δ(complexed/non-complexed), and the κ into κ(1-3). From an anaesthetic perspective, the suggestions that µ(1) produced analgesia and µ(2) produced respiratory depression are particularly important. However, subsequent to the formal identification of the primary opioid receptors (MOP/DOP/KOP/NOP) by cloning and the use of this information to produce knockout animals, evidence for these additional subtypes is lacking. Indeed, knockout of a single gene (and hence receptor) results in a loss of all function associated with that receptor. In the case of MOP knockout, analgesia and respiratory depression is lost. This suggests that further sub-classification of the primary types is unwise. So how can the wealth of pharmacological data be reconciled with new molecular information? In addition to some simple misclassification (κ(3) is probably NOP), there are several possibilities which include: (i) alternate splicing of a common gene product, (ii) receptor dimerization, (iii) interaction of a common gene product with other receptors/signalling molecules, or (iv) a combination of (i)-(iii). Assigning variations in ligand activity (pharmacological subtypes) to one or more of these molecular suggestions represents an interesting challenge for future opioid research.
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MESH Headings
- Artifacts
- Humans
- Receptors, Opioid/classification
- Receptors, Opioid/genetics
- Receptors, Opioid/physiology
- Receptors, Opioid, delta/genetics
- Receptors, Opioid, delta/physiology
- Receptors, Opioid, kappa/genetics
- Receptors, Opioid, kappa/physiology
- Receptors, Opioid, mu/genetics
- Receptors, Opioid, mu/physiology
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Affiliation(s)
- N Dietis
- Department of Cardiovascular Sciences (Pharmacology and Therapeutics Group), Division of Anaesthesia, Critical Care and Pain Management, University of Leicester, Leicester Royal Infirmary, Leicester LE1 5WW, UK
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19
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Fukuda K. [Mechanism of general anesthesia and antinociception]. Masui 2011; 60:590-6. [PMID: 21626863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Nitrous oxide exhibits antinociceptive effects by inhibition of transmission of nociceptive information from the primary afferent neuron to the spinal cord neuron through the activation of the descending inhibitory pathway. Furthermore, nitrous oxide might directly modulate the nociceptive transmission at the dorsal horn of the spinal cord. Analysis of knockout mice and pharmacological analysis suggest that the K -opioid receptor and the nociceptin receptor are involved in the antinociceptive effects of nitrous oxide. To elucidate the molecular mechanism in pharmacological effects of nitrous oxide, further investigation is necessary.
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Affiliation(s)
- Kazuhiko Fukuda
- Department of Anesthesia, Kyoto University Hospital, Kyoto 606-8507
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20
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Walker BM, Zorrilla EP, Koob GF. Systemic κ-opioid receptor antagonism by nor-binaltorphimine reduces dependence-induced excessive alcohol self-administration in rats. Addict Biol 2011; 16:116-9. [PMID: 20579007 DOI: 10.1111/j.1369-1600.2010.00226.x] [Citation(s) in RCA: 158] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Altered dynorphin opioid peptide systems contribute to increased ethanol self-administration during withdrawal following chronic alcohol exposure. We previously identified that the κ-opioid receptor antagonist nor-binaltorphimine (nor-BNI) selectively reduced ethanol self-administration in dependent animals. The purpose of this study was twofold: (1) determine whether peripherally administered nor-BNI could reduce dependence-induced ethanol self-administration and (2) confirm the selective κ-opioid effects of nor-BNI by administering it 24 hours prior to ethanol self-administration sessions occurring during acute withdrawal. Nor-BNI decreased ethanol self-administration in ethanol-dependent animals, with no effect in nondependent animals. Thus, the κ-opioid/dynorphin system is a viable pharmacotherapeutic target for the treatment of alcoholism.
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21
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Abstract
BACKGROUND AND RATIONALE The dynorphin/kappa opioid receptor (KOR) system has been implicated as a critical component of the stress response. Stress-induced activation of dynorphin-KOR is well known to produce analgesia, and more recently, it has been implicated as a mediator of stress-induced responses including anxiety, depression, and reinstatement of drug seeking. OBJECTIVE Drugs selectively targeting specific KOR signaling pathways may prove potentially useful as therapeutic treatments for mood and addiction disorders. RESULTS KOR is a member of the seven transmembrane spanning (7TM) G-protein coupled receptor (GPCR) superfamily. KOR activation of pertussis toxin-sensitive G proteins leads to Galphai/o inhibition of adenylyl cyclase production of cAMP and releases Gbetagamma, which modulates the conductances of Ca(+2) and K(+) channels. In addition, KOR agonists activate kinase cascades including G-protein coupled Receptor Kinases (GRK) and members of the mitogen-activated protein kinase (MAPK) family: ERK1/2, p38 and JNK. Recent pharmacological data suggests that GPCRs exist as dynamic, multi-conformational protein complexes that can be directed by specific ligands towards distinct signaling pathways. Ligand-induced conformations of KOR that evoke beta-arrestin-dependent p38 MAPK activation result in aversion; whereas ligand-induced conformations that activate JNK without activating arrestin produce long-lasting inactivation of KOR signaling. CONCLUSIONS In this review, we discuss the current status of KOR signal transduction research and the data that support two novel hypotheses: (1) KOR selective partial agonists that do not efficiently activate p38 MAPK may be useful analgesics without producing the dysphoric or hallucinogenic effects of selective, highly efficacious KOR agonists and (2) KOR antagonists that do not activate JNK may be effective short-acting drugs that may promote stress-resilience.
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Affiliation(s)
- Michael R Bruchas
- Department of Pharmacology, University of Washington, Seattle, WA 98195, USA
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22
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Abstract
BACKGROUND AND RATIONALE Pain is a complex sensory experience, involving cognitive factors, environment (setting, society, and culture), experience, and gender and is modulated significantly by the central nervous system (CNS). The mechanisms by which opioid analgesics work are understood, but this class of drugs is not ideal as either an analgesic or anti-hyperalgesic. Accordingly, considerable effort continues to be directed at improved understanding of nociceptor function and development of selective analgesics that do not have the unwanted effects associated with opioid analgesics. OBJECTIVE The purpose of this paper is to provide a review of the role of KOP receptors in the modulation of pain and highlight several chemotypes currently being explored as peripherally restricted KOP ligands. RESULTS A growing body of literature has shown that KOP receptors are implicated in a variety of behavioral pain models. Several different classes of peripherally restricted peptidic and nonpeptidic KOP agonists have been identified and show utility in treating painful conditions. CONCLUSION The pharmacological profile of KOP agonists in visceral pain models suggest that peripherally restricted KOP agonists are potentially useful for a variety of peripheral pain states. Further, clinical investigation of peripherally restricted KOP agonists will help to clarify the painful conditions where KOP agonists will be most effective.
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MESH Headings
- Analgesics, Opioid/pharmacology
- Analgesics, Opioid/therapeutic use
- Animals
- Disease Models, Animal
- Humans
- Mechanoreceptors/physiology
- Nociceptors/physiology
- Pain/drug therapy
- Pain/metabolism
- Pain/physiopathology
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/antagonists & inhibitors
- Receptors, Opioid, kappa/physiology
- Receptors, Opioid, mu/agonists
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Affiliation(s)
- Bronwyn Kivell
- School of Biological Sciences, Victoria University of Wellington, P.O. Box 600, Wellington, New Zealand
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23
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Abstract
Moderate dehydration impairs concentration and co-ordination, whereas severe dehydration can cause seizures, brain damage or death. To slow the progression of dehydration until body fluids can be replenished by drinking, the increased body fluid osmolality associated with dehydration increases vasopressin (antidiuretic hormone) secretion from the posterior pituitary gland. Increased vasopressin secretion reduces water loss in the urine by promoting water reabsorption in the collecting ducts of the kidney. Vasopressin secretion is largely determined by action potential discharge in vasopressin neurones, and depends on both the rate and pattern of discharge. Vasopressin neurone activity depends on intrinsic and extrinsic mechanisms. We review recent advances in our understanding of the physiological regulation of vasopressin neurone activity patterning and the mechanisms by which this is altered to cope with the increased secretory demands of dehydration.
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Affiliation(s)
- V Scott
- Centre for Neuroendocrinology and Department of Physiology, Otago School of Medical Sciences, University of Otago, Dunedin 9054, New Zealand
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24
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Chevillard L, Mégarbane B, Baud FJ, Risède P, Declèves X, Mager D, Milan N, Ricordel I. Mechanisms of respiratory insufficiency induced by methadone overdose in rats. Addict Biol 2010; 15:62-80. [PMID: 20002023 DOI: 10.1111/j.1369-1600.2009.00184.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Methadone may cause respiratory depression. We aimed to understand methadone-related effects on ventilation as well as each opioid-receptor (OR) role. We studied the respiratory effects of intraperitoneal methadone at 1.5, 5, and 15 mg/kg (corresponding to 80% of the lethal dose-50%) in rats using arterial blood gases and plethysmography. OR antagonists, including intravenous 10 mg/kg-naloxonazine at 5 minutes (mu-OR antagonist), subcutaneous 30 mg/kg-naloxonazine at 24 hours (micro1-OR antagonist), 3 mg/kg-naltrindole at 45 minutes (delta-OR antagonist) and 5 mg/kg-Nor-binaltorphimine at 6 hours (kappa-OR antagonist) were pre-administered. Plasma concentrations of methadone enantiomers were measured using high-performance liquid chromatography coupled to mass-spectrometry. Methadone dose-dependent inspiratory time (T(I)) increase tended to be linear. Respiratory depression was observed only at 15 mg/kg and characterized by an increase in expiratory time (T(E)) resulting in hypoxemia and respiratory acidosis. Intravenous naloxonazine completely reversed all methadone-related effects on ventilation, while subcutaneous naloxonazine reduced its effects on pH (P < 0.05), PaCO(2) (P < 0.01) and T(E) (P < 0.001) but only partially on T(I) (P < 0.001). Naltrindole reduced methadone-related effects on T(E) (P < 0.001). Nor-binaltorphimine increased methadone-related effects on pH and PaO(2) (P < 0.05) Respiratory effects as a function of plasma R-methadone concentrations showed a decrease in PaO(2) (EC(50): 1.14 microg/ml) at lower concentrations than those necessary for PaCO(2) increase (EC(50): 3.35 microg/ml). Similarly, increased T(I) (EC(50): 0.501 microg/ml) was obtained at lower concentrations than those for T(E) (EC(50): 4.83 microg/ml). Methadone-induced hypoxemia is caused by mu-ORs and modulated by kappa-ORs. Additionally, methadone-induced increase in T(E) is caused by mu1- and delta-opioid receptors while increase in T(I) is caused by mu-ORs.
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MESH Headings
- Acidosis, Respiratory/chemically induced
- Acidosis, Respiratory/physiopathology
- Animals
- Dose-Response Relationship, Drug
- Drug Overdose/physiopathology
- Exhalation/drug effects
- Exhalation/physiology
- Hypoxia/chemically induced
- Hypoxia/physiopathology
- Injections, Intraperitoneal
- Injections, Intravenous
- Injections, Subcutaneous
- Male
- Methadone/pharmacokinetics
- Methadone/toxicity
- Narcotic Antagonists/pharmacology
- Narcotics/pharmacokinetics
- Narcotics/toxicity
- Oxygen/blood
- Rats
- Rats, Sprague-Dawley
- Receptors, Opioid/drug effects
- Receptors, Opioid/physiology
- Receptors, Opioid, delta/drug effects
- Receptors, Opioid, delta/physiology
- Receptors, Opioid, kappa/drug effects
- Receptors, Opioid, kappa/physiology
- Receptors, Opioid, mu/drug effects
- Receptors, Opioid, mu/physiology
- Respiratory Insufficiency/physiopathology
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Affiliation(s)
- Lucie Chevillard
- Université Paris-Descartes, Faculté de Pharmacie, Neuropsychopharmacologie des addictions, CNRS, UMR 7157, Paris, France
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Clayton CC, Xu M, Chavkin C. Tyrosine phosphorylation of Kir3 following kappa-opioid receptor activation of p38 MAPK causes heterologous desensitization. J Biol Chem 2009; 284:31872-81. [PMID: 19773548 PMCID: PMC2797258 DOI: 10.1074/jbc.m109.053793] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Revised: 09/16/2009] [Indexed: 01/05/2023] Open
Abstract
Prior studies showed that tyrosine 12 phosphorylation in the N-terminal, cytoplasmic domain of the G-protein-gated inwardly rectifying potassium channel, K(ir)3.1 facilitates channel deactivation by increasing intrinsic GTPase activity of the channel. Using a phosphoselective antibody directed against this residue (pY12), we now report that partial sciatic nerve ligation increased pY12-K(ir)3.1-immunoreactivity (ir) in the ipsilateral dorsal horn of wild-type mice, but not in mice lacking the kappa-opioid receptor (KOR) or lacking the G-protein receptor kinase 3 (GRK3) genes. Treatment of AtT-20 cells stably expressing KOR-GFP with the selective KOR agonist U50,488 increased both phospho-p38-ir and pY12-K(ir)3.1-ir. The U50,488-induced increase in pY12-K(ir)3.1-ir was blocked by the p38 inhibitor SB203580. Cells expressing KOR(S369A)-GFP did not increase either phospho-p38-ir or pY12-K(ir)3.1-ir following U50,488 treatment. Whole cell voltage clamp of AtT-20 cells expressing KOR-GFP demonstrated that p38 activation by U50,488 reduced somatostatin-evoked K(ir)3 currents. This heterologous desensitization was blocked by SB203580 and was not evident in cells expressing KOR(S369A)-GFP. Tyrosine phosphorylation of K(ir)3.1 was likely mediated by p38 MAPK activation of Src kinase. U50,488 also increased (pY418)Src-ir; this increase was blocked by SB203580 and not evident in KOR(S369A)-GFP expressing AtT20 cells; the Src inhibitor PP2 blocked the U50,488-induced increase in pY12-K(ir)3.1-ir; and the heterologous desensitization of K(ir)3 currents was blocked by PP2. These results suggest that KOR causes phosphorylation of Y12-K(ir)3.1 and channel inhibition through a GRK3-, p38 MAPK- and Src-dependent mechanism. Reduced inward potassium current following nerve ligation would increase dorsal horn neuronal excitability and may contribute to the neuropathic pain response.
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Affiliation(s)
- Cecilea C. Clayton
- From the Department of Pharmacology, University of Washington, Seattle, Washington 98195
| | - Mei Xu
- From the Department of Pharmacology, University of Washington, Seattle, Washington 98195
| | - Charles Chavkin
- From the Department of Pharmacology, University of Washington, Seattle, Washington 98195
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26
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Logrip ML, Janak PH, Ron D. Blockade of ethanol reward by the kappa opioid receptor agonist U50,488H. Alcohol 2009; 43:359-65. [PMID: 19671462 DOI: 10.1016/j.alcohol.2009.05.001] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2008] [Revised: 05/11/2009] [Accepted: 05/15/2009] [Indexed: 11/17/2022]
Abstract
Alcoholism is a pervasive social problem, and thus understanding factors that regulate alcohol (ethanol) reward is important for designing effective therapies. One putative regulatory system includes the kappa opioid receptor (KOR) and its endogenous ligand, dynorphin. Previously, we demonstrated that acute ethanol increased preprodynorphin expression via brain-derived neurotrophic factor (BDNF) in striatal neurons, and that blockade of the KOR attenuated decreases in ethanol intake observed following increased expression of BDNF. As high doses of KOR agonists can generate an aversive state, we hypothesized that endogenous dynorphin may regulate ethanol intake by interfering with the rewarding properties of ethanol. We found that low, nonaversive doses of the KOR agonist U50,488H blocked the rewarding properties of ethanol during conditioning, thus impairing the acquisition of conditioned place preference. Importantly, we demonstrate that U50,488H also inhibited the conditioned increase in locomotor activation normally observed in the ethanol-paired chamber on test day. Taken together, these data indicate that the KOR/dynorphin system may acutely regulate ethanol intake via inhibition of the rewarding properties of ethanol.
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Affiliation(s)
- Marian L Logrip
- The Ernest Gallo Research Center, Suite 200, Emeryville, CA 94608, USA
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27
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Luz PA, Saraiva R, Almeida T, Fregoneze JB, De Castro e Silva E. Blockade of central kappa-opioid receptors inhibits the antidipsogenic effect of interleukin-1beta. Neuropeptides 2009; 43:93-103. [PMID: 19217659 DOI: 10.1016/j.npep.2008.12.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Revised: 11/27/2008] [Accepted: 12/31/2008] [Indexed: 10/21/2022]
Abstract
The objective of the present study was to investigate the role of brain kappa-opioid receptors (KOR) in the antidipsogenic effect promoted by third ventricle injections of interleukin-1beta (IL-1beta). Wistar male rats were submitted to three different, thirst-inducing, physiological conditions: dehydration induced by water deprivation, hyperosmolarity induced by salt-load and hypovolemia induced by polyethylene glycol subcutaneous injection. Third ventricle injections of IL-1beta significantly inhibited the increase in water intake observed in those situations. The pharmacological blockade of central KOR by the selective KOR antagonist nor-binaltorphimine (BNI) at different doses significantly inhibited the antidipsogenic effect induced by the central administration of IL-1beta in all conditions tested: dehydration, hypovolemia and hyperosmolarity. The central administration of IL-1beta failed to induce any locomotor deficit, as verified in an open field test. Stimulation of the central interleukinergic component did not result in any general suppression of ingestive behavior since no change in saccharin intake was recorded during a dessert test in animals receiving central injections of IL-1beta. Furthermore, the inhibitory effects of IL-1beta on water intake cannot be attributed to sickness-like effects induced by these compounds, since an aversion test excluded this possibility. In summary, the data shown in the present study clearly show that the antidipsogenic effect observed in rats following third ventricle injections of IL-1beta depend on the functional integrity of a brain kappa-opioid-dependent component.
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Affiliation(s)
- P A Luz
- Department of Biological Sciences, State University of Southwest Bahia, 45200-000 Jequié, Bahia, Brazil
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28
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Lasukova TV, Maslov LN, Gorbunov AC, Tsibul'nuikov SI. [Intracellular mechanisms of opioidergic regulation of the myocardial function during normoxia and postischemic reperfusion]. Ross Fiziol Zh Im I M Sechenova 2009; 95:376-386. [PMID: 19505040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Cardioprotective and inotropic effects of selective agonists of delta1- and k1-opioid receptors (OR): DPDPE (0.1 microM/L) and U-50.488 (0.1 microM/L) were studied during 45 min global ischemia and 30 min reperfusion of the rat isolated perfused heart. Activation of both OR types promoted a 2-fold reduction in reperfusion leakage of creatine kinase. Cardioprotective effect of U-50.488 was accompanied by a 2-fold decrease in cAMP levels in myocardium. The selective delta1-agonist DPDPE had no effect on the cAMP content. Cardioprotective effect of DPDPE was not demonstrated after inhibition of Ca2+-ATPase in sarcoplasmic reticulum (SR) by cyclopiazonic acid. Stimulation of myocardial delta1- and K1-OR decreased the heart rate and force of contraction both before ischemia and during reperfusion. In summary, cardioprotective effect of U-50.488 depends on the reduction in myocardial cAMP levels whereas cytoprotective effect of DPDPE is mediated via opioidergic alteration in Ca2+-transport at SR level. Decrease in pump function of heart in response to OR activation does not depend upon alteration in cAMP levels in the myocardium.
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MESH Headings
- 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer/pharmacology
- 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer/therapeutic use
- Animals
- Cardiotonic Agents/pharmacology
- Cardiotonic Agents/therapeutic use
- Creatine Kinase/blood
- Cyclic AMP/metabolism
- Enkephalin, D-Penicillamine (2,5)-/pharmacology
- Enkephalin, D-Penicillamine (2,5)-/therapeutic use
- Heart Rate/drug effects
- Heart Rate/physiology
- Male
- Myocardial Contraction/drug effects
- Myocardial Contraction/physiology
- Myocardial Reperfusion Injury/drug therapy
- Myocardial Reperfusion Injury/metabolism
- Myocardial Reperfusion Injury/physiopathology
- Rats
- Rats, Wistar
- Receptors, Opioid, delta/antagonists & inhibitors
- Receptors, Opioid, delta/physiology
- Receptors, Opioid, kappa/antagonists & inhibitors
- Receptors, Opioid, kappa/physiology
- Sarcoplasmic Reticulum/physiology
- Sarcoplasmic Reticulum Calcium-Transporting ATPases/metabolism
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Sakurada S, Sawai T, Mizoguchi H, Watanabe H, Watanabe C, Yonezawa A, Morimoto M, Sato T, Komatsu T, Sakurada T. Possible involvement of dynorphin A release via mu1-opioid receptor on supraspinal antinociception of endomorphin-2. Peptides 2008; 29:1554-60. [PMID: 18571771 DOI: 10.1016/j.peptides.2008.04.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2008] [Revised: 04/17/2008] [Accepted: 04/18/2008] [Indexed: 11/26/2022]
Abstract
It has been demonstrated that the antinociception induced by i.t. or i.c.v. administration of endomorphins is mediated through mu-opioid receptors. Moreover, though endomorphins do not have appreciable affinity for kappa-opioid receptors, pretreatment with the kappa-opioid receptor antagonist nor-binaltorphimine markedly blocks the antinociception induced by i.c.v.- or i.t.-injected endomorphin-2, but not endomorphin-1. These evidences propose the hypothesis that endomorphin-2 may initially stimulate the mu-opioid receptors, which subsequently induces the release of dynorphins acting on kappa-opioid receptors to produce antinociception. The present study was performed to determine whether the release of dynorphins by i.c.v.-administered endomorphin-2 is mediated through mu-opioid receptors for producing antinociception. Intracerebroventricular pretreatment with an antiserum against dynorphin A, but not dynorphin B or alpha-neo-endorphin, and s.c. pretreatment with kappa-opioid receptor antagonist nor-binaltorphimine dose-dependently attenuated the antinociception induced by i.c.v.-administered endomorphin-2, but not endomorphin-1 and DAMGO. The attenuation of endomorphin-2-induced antinociception by pretreatment with antiserum against dynorphin A or nor-binaltorphimine was dose-dependently eliminated by additional s.c. pretreatment with a selective mu-opioid receptor antagonist beta-funaltrexamine or a selective mu1-opioid receptor antagonist naloxonazine at ultra low doses, which are inactive against micro-opioid receptor agonists in antinociception, suggesting that endomorphin-2 stimulates distinct subclass of micro1-opioid receptor that induces the release of dynorphin A acting on kappa-opioid receptors in the brain. It concludes that the antinociception induced by supraspinally administered endomorphin-2 is in part mediated through the release of endogenous kappa-opioid peptide dynorphin A, which is caused by the stimulation of distinct subclass of micro1-opioid receptor.
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Affiliation(s)
- Shinobu Sakurada
- Department of Physiology and Anatomy, Tohoku Pharmaceutical University, 4-4-1 Komatsushima, Sendai 981-8558, Japan.
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30
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Schepers R, Mahoney JL, Gehrke BJ, Shippenberg TS. Endogenous kappa-opioid receptor systems inhibit hyperalgesia associated with localized peripheral inflammation. Pain 2008; 138:423-439. [PMID: 18355964 PMCID: PMC2553515 DOI: 10.1016/j.pain.2008.01.023] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2007] [Revised: 12/20/2007] [Accepted: 01/22/2008] [Indexed: 11/20/2022]
Abstract
Peripheral inflammation evokes functional and biochemical changes in the periphery and spinal cord which result in central sensitization and hypersensitivity. Inhibitory control systems from the rostral ventromedial medulla (RVM) are also activated. The present study investigates whether endogenous kappa-opioid receptor (KOPr) systems contribute to these neuroadaptations. Inflammation was induced by intraplantar injection of complete Freund's adjuvant (CFA) into one hindpaw. Mechanical and thermal thresholds were determined using the Von Frey and radiant heat tests, respectively. KOPr gene deletion in mice or systemic administration of the long-acting KOPr antagonist, norbinaltorphimine (norBNI) significantly exacerbated mechanical and thermal hypersensitivity of the ipsilateral, inflamed paw. Thermal and mechanical thresholds of the non-inflamed, contralateral hindpaw were unaffected by CFA treatment. However, gene deletion as well as norBNI treatment resulted in mechanical, but not thermal hypersensitivity of the non-inflamed paw. Similar results were obtained when norBNI was administered intrathecally or into the RVM in rats. These data demonstrate a previously unrecognized role of endogenous KOPr systems in inhibiting hyperalgesia during inflammation. Furthermore, they demonstrate that decreased KOPr activity in either the spinal cord or RVM not only enhances mechanical and thermal hyperalgesia of the inflamed limb but also leads to an unmasking of mechanical hyperalgesia at a site remote from inflammation. The differential effects of KOPr antagonism on mechanical versus thermal thresholds for the non-inflamed paw support the notion that distinct neuroanatomical or neurochemical mechanisms modulate the processing of thermal versus mechanical stimuli.
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Affiliation(s)
- R.J. Schepers
- University of Maryland School of Medicine, 660 West Redwood Street, Baltimore, MD 21201, USA
- Integrative Neuroscience Section, Behavioral Neuroscience Branch, National Institutes of Health/National Institute on Drug Abuse Intramural Research Program, 333 Cassell Drive, Baltimore, MD 21224, USA
| | - Janet Lynn Mahoney
- Integrative Neuroscience Section, Behavioral Neuroscience Branch, National Institutes of Health/National Institute on Drug Abuse Intramural Research Program, 333 Cassell Drive, Baltimore, MD 21224, USA
| | - Brenda Jean Gehrke
- Integrative Neuroscience Section, Behavioral Neuroscience Branch, National Institutes of Health/National Institute on Drug Abuse Intramural Research Program, 333 Cassell Drive, Baltimore, MD 21224, USA
| | - Toni Shaun Shippenberg
- Integrative Neuroscience Section, Behavioral Neuroscience Branch, National Institutes of Health/National Institute on Drug Abuse Intramural Research Program, 333 Cassell Drive, Baltimore, MD 21224, USA
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31
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Menéndez L, Hidalgo A, Meana A, Poras H, Fournié-Zaluski MC, Roques BP, Baamonde A. Inhibition of osteosarcoma-induced thermal hyperalgesia in mice by the orally active dual enkephalinase inhibitor PL37. Potentiation by gabapentin. Eur J Pharmacol 2008; 596:50-5. [PMID: 18692494 DOI: 10.1016/j.ejphar.2008.07.043] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2008] [Revised: 07/11/2008] [Accepted: 07/23/2008] [Indexed: 11/18/2022]
Abstract
We have previously shown that stimulation of peripheral opioid receptors by exogenous opiates counteracts the thermal hyperalgesia elicited by a tibial osteosarcoma due to intraosteal inoculation of NCTC 2472 cells to mice. Aiming to study whether pheripheral endogenous enkephalins could also counteract this painful symptom, we assayed in this model the effects of PL37, an orally active dual inhibitor of enkephalin inactivating enzymes. Oral administration of PL37 (25 mg/kg) completely supressed osteosarcoma-induced thermal hyperalgesia through the activation of micro-opioid receptors, since the administration of cyprodime (1 mg/kg) inhibited its antihyperalgesic effect. Neither naltrindole (0.1 mg/kg) nor nor-binaltorphimine (10 mg/kg) modified this PL37-induced antihyperalgesic effect. Moreover, the inhibition of the antihyperalgesic effect induced by PL37 after the administration of naloxone-methiodide (2 mg/kg), a non selective opioid antagonist that does not cross the blood-brain barrier, demonstrates the involvement of peripheral opioid receptors. In contrast, centrally mediated effects may be detected when assaying a higher dose of PL37 (50 mg/kg). Besides, the administration of gabapentin (6.25-25 mg/kg, i.p.) dose-dependently inhibited osteosarcoma-induced thermal hyperalgesia. Interestingly, the combined administration of subeffective doses of PL37 and gabapentin completely prevented this type of thermal hyperalgesia. An isobolographic analysis of this interaction demonstrated a synergistic interaction between both drugs.
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MESH Headings
- Administration, Oral
- Amines/therapeutic use
- Analgesics/therapeutic use
- Animals
- Bone Neoplasms/complications
- Bone Neoplasms/physiopathology
- Cyclohexanecarboxylic Acids/therapeutic use
- Disulfides/therapeutic use
- Drug Synergism
- Gabapentin
- Hot Temperature
- Hyperalgesia/drug therapy
- Hyperalgesia/etiology
- Hyperalgesia/physiopathology
- Mice
- Naloxone/analogs & derivatives
- Naloxone/pharmacology
- Neprilysin/antagonists & inhibitors
- Osteosarcoma/complications
- Osteosarcoma/physiopathology
- Propylamines/therapeutic use
- Quaternary Ammonium Compounds/pharmacology
- Receptors, Opioid, delta/antagonists & inhibitors
- Receptors, Opioid, delta/physiology
- Receptors, Opioid, kappa/antagonists & inhibitors
- Receptors, Opioid, kappa/physiology
- Receptors, Opioid, mu/antagonists & inhibitors
- Receptors, Opioid, mu/physiology
- gamma-Aminobutyric Acid/therapeutic use
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Affiliation(s)
- Luis Menéndez
- Laboratorio de Farmacología, Facultad de Medicina, Instituto Universitario de Oncología del Principado de Asturias (IUOPA), Universidad de Oviedo, c/ Julián Clavería 6, Oviedo, Asturias, Spain
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32
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Cheĭdo MA, Idova GV. [Impact of serotonin 1A receptors in the kappa-opioid immunosuppression]. Ross Fiziol Zh Im I M Sechenova 2008; 94:807-813. [PMID: 18767393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The data obtained indicate that rimorphin (0.1 mg/kg), a specific kappa-agonist, evoked a significant inhibition of the immune response in CBA mice. Pretreatment of the animals with 8-OH-DPAT (0.1 mg/kg), a selective serotonin (5-HT) agonist, activating presynaptic 5-HT(1A) receptors, or WAY-100635 (1.0 mg/kg), a selective 5-HT(1A) receptors blocker of postsynaptic 5-HTIA receptors, prevents kappa-opioid effect. The present data indicate that kappa-opioid-induced immunosuppression is due to the involvement of the 5-HT-ergic mechanisms that are modulated via pre- and postsynaptic 5-HT(1A) receptors.
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Abstract
Eleven single-nucleotide polymorphisms (SNPs) spanning OPRD1 were examined in 1063 European Americans (EAs) (620 cases with substance dependence (SD), including 557 with alcohol dependence (AD), 225 with cocaine dependence (CD) and 111 with opioid dependence (OD), and 443 controls). Nominally significant associations (P<0.05) of five SNPs with SD were observed; only the association of the non-synonymous variant G80T with OD remained significant after correction for multiple testing using SNPSpD. Haplotype analyses with six tag SNPs indicated that a specific haplotype GCAACT, which harbors G80T G-allele and C921T C-allele, was significantly associated with AD (chi(2)=14.82, degrees of freedom (d.f.)=1, P<0.001), CD (chi(2)=9.19, d.f.=1, P=0.002) and OD (chi(2)=20.68, d.f.=1, P<0.001). Logistic regression analyses, with sex and age being considered, demonstrated that this haplotype had a risk effect on AD (P=0.03, beta=1.86, odds ratio (OR)=6.43) and especially on OD (P<0.001, beta=3.92, OR=50.57). Moreover, seven SNPs covering OPRK1 were examined in the majority of the above subjects (390 cases, including 327 AD, 177 CD and 97 OD subjects, and 358 controls). Although no significant differences in allele, genotype or haplotype frequency distributions were seen between cases and controls, a specific OPRK1 haplotype, GGCTTCT, was significantly associated with AD (chi(2)=8.12, d.f.=1, P=0.004). Logistic regression analyses also revealed its risk effect on AD (P=0.009, beta=1.06, OR=2.90). Population stratification artifact was not observed in the sample. Taken together, our findings supported a positive association between OPRD1 variants and SD, and a positive haplotypic association between OPRK1 and AD in EAs.
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Affiliation(s)
- H Zhang
- VA Connecticut Healthcare System, West Haven Campus, West Haven, CT, USA
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - HR Kranzler
- Department of Psychiatry, University of Connecticut School of Medicine, Farmington, CT, USA
| | - B-Z Yang
- VA Connecticut Healthcare System, West Haven Campus, West Haven, CT, USA
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - X Luo
- VA Connecticut Healthcare System, West Haven Campus, West Haven, CT, USA
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - J Gelernter
- VA Connecticut Healthcare System, West Haven Campus, West Haven, CT, USA
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
- Department of Neurobiology, Yale University School of Medicine, New Haven, CT, USA
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Abstract
In the present study, we investigated the effects of psychostimulant exposure on kappa-opioid peptide (KOP) receptor signaling in the rat mesolimbic system. A single subcutaneous (s.c.) injection of amphetamine (2.5 mg/kg) reduced the KOP receptor-mediated inhibition of glutamate release in the nucleus accumbens shell, as a consequence of KOP receptor desensitization. This effect was blocked by dopamine (DA) receptor antagonists or the nonselective opioid antagonist, naltrexone (1 mg/kg, s.c.), and mimicked by the KOP receptor agonists U69593 (0.32 mg/kg, s.c.) and dynorphin (1 microM), indicating that an amphetamine-induced release of dynorphin is producing a long-lasting desensitization of the KOP receptor. Despite the fact that amphetamine also increases dynorphin release in the ventral tegmental area (VTA), KOP receptor function in this region was not affected by amphetamine; there was no difference in the KOP receptor-mediated change in firing rate or resting membrane potential measured in VTA neurons from saline- or amphetamine-treated animals. This study demonstrates that amphetamine can produce regionally selective adaptations in KOP receptor signaling, which may, in turn, alter the effects of subsequent drug exposure.
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Affiliation(s)
- Yan-fang Xia
- Ernest Gallo Clinic and Research Center, University of California, San Francisco, CA, USA
| | - Li He
- Ernest Gallo Clinic and Research Center, University of California, San Francisco, CA, USA
| | - Jennifer L Whistler
- Ernest Gallo Clinic and Research Center, University of California, San Francisco, CA, USA
- Department of Neurology and Wheeler Center for the Neurobiology of Addiction, University of California, San Francisco, CA, USA
| | - Gregory O Hjelmstad
- Ernest Gallo Clinic and Research Center, University of California, San Francisco, CA, USA
- Department of Neurology and Wheeler Center for the Neurobiology of Addiction, University of California, San Francisco, CA, USA
- *Correspondence: Dr GO Hjelmstad, Ernest Gallo Clinic and Research Center, 5858 Horton Street, Suite 200, Emeryville, CA 94608, USA, Tel: + 1 510 985 3927, Fax: + 1 510 985 3101, E-mail:
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Trescot AM, Datta S, Lee M, Hansen H. Opioid pharmacology. Pain Physician 2008; 11:S133-S153. [PMID: 18443637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
BACKGROUND Mu agonists have been an important component of pain treatment for thousands of years. The usual pharmacokinetic parameters (half-life, clearance, volume of distribution) of opioids have been known for some time. However, the metabolism has, until recently, been poorly understood, and there has been recent interest in the role of metabolites in modifying the pharmacodynamic response in patients, in both analgesia and adverse effects. A number of opioids are available for clinical use, including morphine, hydromorphone, levorphanol, oxycodone, and fentanyl. Advantages and disadvantages of various opioids in the management of chronic pain are discussed. OBJECTIVE This review looks at the structure, chemistry, and metabolism of opioids in an effort to better understand the side effects, drug interactions, and the individual responses of patients receiving opioids for the treatment of intractable pain. CONCLUSION Mu receptor agonists and agonist-antagonists have been used throughout recent medical history for the control of pain and for the treatment of opiate induced side effects and even opiate withdrawal syndromes.
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MESH Headings
- Analgesics, Opioid/chemistry
- Analgesics, Opioid/pharmacokinetics
- Analgesics, Opioid/pharmacology
- Analgesics, Opioid/therapeutic use
- Drug Interactions
- Humans
- Models, Molecular
- Narcotic Antagonists/pharmacology
- Receptors, Opioid, delta/drug effects
- Receptors, Opioid, delta/physiology
- Receptors, Opioid, kappa/drug effects
- Receptors, Opioid, kappa/physiology
- Receptors, Opioid, mu/drug effects
- Receptors, Opioid, mu/physiology
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Arita H, Hayashida M, Shu H, Xu H, Sekiyama H, Hanaoka K. [Application of herb medicine in pain clinic--focusing on the basic research of Aconiti tuber]. Masui 2007; 56 Suppl:S199-S211. [PMID: 18051466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
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Guo HT, Zhang RH, Huang LY, Li J, Liu YL, Bi H, Zhang QY, Wang YM, Sun X, Ma XL, Cheng L, Liu JC, Yu SQ, Yi DH, Pei JM. Mechanisms Involved in the Hypotensive Effect of a κ-Opioid Receptor Agonist in Hypertensive Rats. Arch Med Res 2007; 38:723-9. [PMID: 17845890 DOI: 10.1016/j.arcmed.2007.04.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2007] [Accepted: 04/02/2007] [Indexed: 10/22/2022]
Abstract
BACKGROUND It remains unclear whether the activation of kappa-opioid receptors has strong hypotensive effects under hypertensive condition, and the underlying mechanisms have not yet been investigated. Therefore, the present study is designed to use spontaneously hypertensive rats (SHR) to investigate the effects of a kappa-opioid receptor agonist on the regulation of urinary formation in hypertensive conditions and to identify its underlying mechanism. METHODS The hemodynamics, urine flow rate, vasodilatation of isolated renal artery, and plasma hormones were determined by physiological in vivo experimental technique, isolated artery perfusion technique and radioimmunoassay. RESULTS Intravenous administration of U50, 448H significantly decreased mean arterial blood pressure in both Wistar-Kyoto (WKY) rats and SHR. However, the blood pressure vasodepressor effect of U50, 448H was much more profound in SHR than in WKY rats. Administration of U50, 448H in SHR not only caused significantly greater effects in increasing urine volume and decreasing plasma anti-diuretic hormone than in WKY rats, but also caused significant reduction in plasma angiotensin. Moreover, vasodilatory effect of U50, 488H was significantly exhibited in the renal artery segments isolated from SHR. All effects described above were abolished by nor-binaltorphimine. CONCLUSIONS These data indicate that the depressor effect of U50, 488H in SHR is significantly stronger than that in WKY rats, and the effect is mediated or modulated by a kappa-opioid receptor sensitive mechanism. The sensitized hypotensive effect of U50, 488H in SHR may be attributed, in part, to its vasodilatory effect, enhanced beneficial effect on plasma humoral factors, and stronger diuretic effect in these hypertensive animals.
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MESH Headings
- 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer/administration & dosage
- 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer/pharmacology
- Angiotensins/blood
- Animals
- Antihypertensive Agents/administration & dosage
- Antihypertensive Agents/pharmacology
- Blood Pressure/drug effects
- Diuresis/drug effects
- Hypertension/drug therapy
- Hypertension/etiology
- Hypertension/physiopathology
- In Vitro Techniques
- Male
- Rats
- Rats, Inbred SHR
- Rats, Inbred WKY
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/physiology
- Renal Artery/drug effects
- Urodynamics/drug effects
- Vasodilation/drug effects
- Vasopressins/blood
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Affiliation(s)
- Hai-Tao Guo
- Department of Physiology, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, PR China
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38
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Abstract
OBJECTIVE To compare the density and binding characteristics of opioid receptor subtypes in horse, rat, and guinea pig cerebral cortex and cerebellum. STUDY DESIGN Prospective receptor binding study. ANIMALS Whole brains were obtained from four neurologically normal adult horses during necropsy. Rat and guinea pig brains were obtained commercially. METHODS The cerebellum and cerebral cortex were dissected from each brain, and tissue homogenates prepared. A radioligand binding technique with the highly selective ligands [(3)H]-DAMGO, [(3)H]-U69593, and [(3)H]-DPDPE was used to identify the mu- (mu), kappa- (kappa) and delta- (delta) opioid receptors, respectively. Competitive binding assays were performed with these ligands and varying concentrations of one of multiple unlabeled ligands. RESULTS While there were marked species differences in relative densities of opioid receptors, all radioligands interacted with their binding sites with high, nanomolar affinity in both the cerebral cortex and cerebellum. In the horse cerebral cortex, the percentages of total opioid binding sites for the mu-, kappa- and delta-receptors were 71%, 14% and 15%, respectively. In the rat and guinea pig cerebral cortex, the corresponding values were 56% mu-, 4% kappa- and 40% delta-receptors, and 25% mu-, 37% kappa- and 38% delta-receptors, respectively. In horse and guinea pig cerebellum, the binding was 37% mu-, 59% kappa- and 4% delta-receptors, and 15% mu-, 76% kappa- and 10% delta-receptors, respectively. For competitive analysis, all competitors of the mu-, kappa- and delta-receptors completely displaced [(3)H]-DAMGO, [(3)H]-U69593, and [(3)H]-DPDPE and had inhibitory constants in the nanomolar range. CONCLUSION AND CLINICAL RELEVANCE Horses used in this study had a greater density of mu-receptors in the cerebral cortex compared with rats and guinea pigs but without further characterization of the functional role of these receptors it is impossible to determine the clinical significance of these data.
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Affiliation(s)
- Sara M Thomasy
- K.L. Maddy Equine Analytical Chemistry Laboratory, California Animal Health and Food Safety Laboratory, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
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Schindler CW, Graczyk Z, Gilman JP, Negus SS, Bergman J, Mello NK, Goldberg SR. Effects of kappa opioid agonists alone and in combination with cocaine on heart rate and blood pressure in conscious squirrel monkeys. Eur J Pharmacol 2007; 576:107-13. [PMID: 17707792 PMCID: PMC2080578 DOI: 10.1016/j.ejphar.2007.07.053] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2007] [Revised: 07/25/2007] [Accepted: 07/26/2007] [Indexed: 11/28/2022]
Abstract
As kappa agonists have been proposed as treatments for cocaine abuse, the cardiovascular effects of the kappa opioid receptor agonists ethylketocyclazocine (EKC) and enadoline were investigated in conscious squirrel monkeys. Both EKC and enadoline increased heart rate with little effect on blood pressure. This effect appeared to be specific for kappa receptors as the mu opioid agonist morphine did not mimic the effects of the kappa agonists. The opioid antagonist naltrexone, at a dose of 1.0 mg/kg, blocked the effect of EKC. An action at both central and peripheral receptors may be responsible for the heart rate increase following kappa agonist treatment. The ganglionic blocker chlorisondamine partially antagonized the effect of EKC on heart rate, suggesting central involvement, while the peripherally-acting agonist ICI 204,448 ((+/-)-1-[2,3- (Dihydro-7-methyl-1H-inden-4-yl)oxy]-3-[(1-methylethyl)amino]-2-butanol hydrochloride) also increased heart rate, supporting a peripheral site of action. When given in combination with cocaine, EKC produced effects that were sub-additive, suggesting that the kappa agonists may be used safely as cocaine abuse treatments.
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Affiliation(s)
- Charles W Schindler
- Preclinical Pharmacology Section, Behavioral Neuroscience Branch, DHHS/NIH/NIDA Intramural Research Program, Baltimore MD (CWS, ZG, JPG, SRG), United States.
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40
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Abstract
The present study tested the hypothesis that κ-opioids modulate the arterial baroreflex control of heart rate in conscious young sheep. Various parameters governing the arterial baroreflex control of heart rate were assessed before and after activation of κ-opiate receptors (KOR) by i.v. administration of the specific KOR agonist U-50488H (experiment 1) or vehicle (experiment 2) to conscious, chronically instrumented lambs aged 42 ± 2 days (n = 6). The 2 experiments were administered in random order at minimum intervals of 48 h. Thirty min after U-50488H treatment, there was an increase in diastolic and mean arterial pressure and in heart rate, returning to control levels by 90 min. A significant increase in the arterial pressure at the midpoint of the baroreflex range and in the minimum heart rate as well as a significant decrease in the heart rate range over which the arterial baroreflex operates were also seen at 30 min after U-50488H, gradually returning to control levels over 120 min. Vehicle had no effect on any of the parameters governing the arterial baroreflex control of heart rate. These data provide the first direct evidence that under physiological conditions in young lambs, the arterial baroreflex control of heart rate is altered after administration of the specific KOR agonist U-50488H, revealing a previously unidentified role for this opioid receptor.
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Affiliation(s)
- Wei Qi
- Department of Physiology and Biophysics, Faculty of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, AB T2N 4N1, Canada
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41
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Caram-Salas NL, Reyes-García G, Bartoszyk GD, Araiza-Saldaña CI, Ambriz-Tututi M, Rocha-González HI, Arreola-Espino R, Cruz SL, Granados-Soto V. Subcutaneous, intrathecal and periaqueductal grey administration of asimadoline and ICI-204448 reduces tactile allodynia in the rat. Eur J Pharmacol 2007; 573:75-83. [PMID: 17643411 DOI: 10.1016/j.ejphar.2007.06.034] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2007] [Revised: 06/11/2007] [Accepted: 06/12/2007] [Indexed: 11/20/2022]
Abstract
The purpose of this study was to assess the possible antiallodynic effect of asimadoline ([N-methyl-N-[1S)-1-phenyl)-2-(13S))-3-hydroxypyrrolidine-1-yl)-ethyl]-2,2-diphenylacetamide HCl]) and ICI-20448 ([2-[3-(1-(3,4-Dichlorophenyl-N-methylacetamido)-2-pyrrolidinoethyl)-phenoxy]acetic acid HCl]), two peripheral selective kappa opioid receptor agonists, after subcutaneous, spinal and periaqueductal grey administration to neuropathic rats. Twelve days after spinal nerve ligation tactile allodynia was observed, along with an increase in kappa opioid receptor mRNA expression in dorsal root ganglion and dorsal horn spinal cord. A non-significant increase in periaqueductal grey was also seen. Subcutaneous (s.c.) administration of asimadoline and ICI-204448 (1-30 mg/kg) dose-dependently reduced tactile allodynia. This effect was partially blocked by s.c., but not intrathecal, naloxone. Moreover, intrathecal administration of asimadoline or ICI-204448 (1-30 mug) reduced tactile allodynia in a dose-dependent manner and this effect was completely blocked by intrathecal naloxone. Microinjection of both kappa opioid receptor agonists (3-30 mug) into periaqueductal grey also produced a naloxone-sensitive antiallodynic effect in rats. Our results indicate that systemic, intrathecal and periaqueductal grey administration of asimadoline and ICI-204448 reduces tactile allodynia. This effect may be a consequence of an increase in kappa opioid receptor mRNA expression in dorsal root ganglion, dorsal horn spinal cord and, to some extent, in periaqueductal grey. Finally, our data suggest that these drugs could be useful to treat neuropathic pain in human beings.
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MESH Headings
- Acetamides/administration & dosage
- Acetamides/pharmacology
- Animals
- Dose-Response Relationship, Drug
- Female
- Injections, Spinal
- Injections, Subcutaneous
- Ligation/adverse effects
- Ligation/methods
- Lumbosacral Plexus/injuries
- Male
- Naloxone/administration & dosage
- Naloxone/pharmacology
- Pain Threshold/drug effects
- Periaqueductal Gray/drug effects
- Periaqueductal Gray/metabolism
- Periaqueductal Gray/physiopathology
- Peripheral Nervous System Diseases/genetics
- Peripheral Nervous System Diseases/physiopathology
- Peripheral Nervous System Diseases/prevention & control
- Pyrrolidines/administration & dosage
- Pyrrolidines/pharmacology
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Wistar
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/genetics
- Receptors, Opioid, kappa/physiology
- Reverse Transcriptase Polymerase Chain Reaction
- Somatosensory Disorders/etiology
- Somatosensory Disorders/physiopathology
- Somatosensory Disorders/prevention & control
- Time Factors
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Affiliation(s)
- Nadia L Caram-Salas
- Departamento de Farmacobiología, Centro de Investigación y de Estudios Avanzados, Sede Sur, México, D.F., Mexico
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42
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Bortolato M, Solbrig MV. The price of seizure control: dynorphins in interictal and postictal psychosis. Psychiatry Res 2007; 151:139-43. [PMID: 17395273 DOI: 10.1016/j.psychres.2006.11.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2006] [Revised: 09/12/2006] [Accepted: 11/02/2006] [Indexed: 11/19/2022]
Abstract
Postictal and interictal psychoses are relatively common complicating factors in the clinical course of epilepsy, yet their neurobiological substrates are poorly understood. Recent evidence shows that kappa opioid receptor (KOR) activation elicits anticonvulsant and psychotomimetic effects. In view of this background, here we introduce the hypothesis that epilepsy-related psychoses may partially result from excessive hippocampal dynorphin release and kappa opioid receptor overstimulation aimed at seizure control.
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Affiliation(s)
- Marco Bortolato
- Department of Pharmacology, University of California, Irvine, Irvine, CA 92697-4292, USA.
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43
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Liu NJ, von Gizycki H, Gintzler AR. Sexually Dimorphic Recruitment of Spinal Opioid Analgesic Pathways by the Spinal Application of Morphine. J Pharmacol Exp Ther 2007; 322:654-60. [PMID: 17488879 DOI: 10.1124/jpet.107.123620] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Current evidence for sex-based nociception and antinociception, largely confined to behavioral measures of pain sensitivity, chronic pain syndromes, and analgesic efficacy, provides little mechanistic insights into biological substrates causally associated with sexual dimorphic pain experience. Spinal cord has been shown to be a central nervous system region in which regulation of opioid antinociceptive substrates manifest sexual dimorphism. This site was therefore chosen to explore whether or not differential mechanisms underlie comparable spinal opioid antinociception in male and female rodents. Intrathecal (i.t.) application of morphine to male and female rats produces a thermal antinociception equivalent in magnitude and temporal profile. Nevertheless, it results from the sex-based differential recruitment of spinal analgesic components. As expected, the spinal micro-opioid receptor is critical for i.t. morphine antinociception in both sexes. However, in females, but not males, activation by i.t. morphine of spinal kappa-opioid receptors is a prerequisite for spinal morphine antinociception. Furthermore, in females, but not males, i.t. application of antidynorphin antibodies substantially attenuates the antinociception produced by i.t. morphine. This indicates that the antinociception that results from the i.t. application of morphine in females requires the functional recruitment of spinal dynorphin. Female-specific recruitment by i.t. morphine of a spinal dynorphin/kappa-opioid receptor pathway results from organizational consequences of ovarian sex steroids and not the absence of testicular hormones. These observations suggest that sexual dimorphic pain and analgesic mechanisms might be far more pervasive than commonly thought and underscore the imperative for including female as well as male subjects in all studies of pain and antinociception.
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MESH Headings
- Animals
- Animals, Newborn
- Antibodies/immunology
- Antibodies/pharmacology
- Dose-Response Relationship, Drug
- Dynorphins/immunology
- Female
- Injections, Spinal
- Male
- Morphine/administration & dosage
- Morphine/pharmacology
- Naltrexone/analogs & derivatives
- Naltrexone/pharmacology
- Narcotic Antagonists/pharmacology
- Neural Pathways/drug effects
- Neural Pathways/physiology
- Orchiectomy
- Ovariectomy
- Pain Threshold/drug effects
- Rats
- Rats, Sprague-Dawley
- Receptors, Opioid, kappa/antagonists & inhibitors
- Receptors, Opioid, kappa/physiology
- Receptors, Opioid, mu/antagonists & inhibitors
- Receptors, Opioid, mu/physiology
- Sex Factors
- Spinal Cord/drug effects
- Spinal Cord/physiology
- Sufentanil/pharmacology
- Virilism/chemically induced
- Virilism/physiopathology
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Affiliation(s)
- Nai-Jiang Liu
- Department of Biochemistry, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, USA
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44
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Woolley JD, Lee BS, Kim B, Fields HL. Opposing effects of intra-nucleus accumbens mu and kappa opioid agonists on sensory specific satiety. Neuroscience 2007; 146:1445-52. [PMID: 17445988 DOI: 10.1016/j.neuroscience.2007.03.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2007] [Revised: 03/02/2007] [Accepted: 03/07/2007] [Indexed: 11/20/2022]
Abstract
Mu opioid (MOP) agonists acting in the nucleus accumbens (NAcc) robustly enhance consumption of palatable foods. In addition, the effect on consumption of palatable foods produced by MOP agonists acting in the NAcc depends on both recent flavor exposure and the availability of a choice between different-flavored foods. In contrast, kappa opioid (KOP) agonists have variable effects on feeding and KOP agonists have MOP opposing behavioral actions when microinjected at several brain sites. We previously demonstrated that NAcc MOP agonists reverse the devaluation (satiety) effect of pre-feeding for a given flavor; in fact, NAcc MOP agonists selectively increase consumption of a recently sampled food. In contrast, in the present study, we found that the selective KOP agonist U50488 injected into the NAcc of rats reduced consumption of a recently sampled flavor while increasing consumption of the flavor that was not pre-fed. Intra-NAcc U50488 did not affect overall consumption or flavor preference in the absence of pre-feeding. The present data, in conjunction with our previous findings, highlight the robust and opposing role of NAcc MOP and KOP opioid receptors in palatability-based food choice and consumption and raise the possibility that an endogenous KOP agonist acting in the NAcc contributes to the phenomenon of sensory specific satiety.
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MESH Headings
- Analgesics/pharmacology
- Analysis of Variance
- Animals
- Behavior, Animal
- Food Preferences/drug effects
- Male
- Nucleus Accumbens/drug effects
- Rats
- Rats, Long-Evans
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/physiology
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/physiology
- Satiety Response/drug effects
- Taste
- Time Factors
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Affiliation(s)
- J D Woolley
- The Ernest Gallo Clinic and Research Center and the Wheeler Center for the Neurobiology of Addiction, Department of Neurology, University of California, San Francisco, San Francisco, CA 94143, USA.
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45
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Xu M, Bruchas MR, Ippolito DL, Gendron L, Chavkin C. Sciatic nerve ligation-induced proliferation of spinal cord astrocytes is mediated by kappa opioid activation of p38 mitogen-activated protein kinase. J Neurosci 2007; 27:2570-81. [PMID: 17344394 PMCID: PMC2104780 DOI: 10.1523/jneurosci.3728-06.2007] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Partial sciatic nerve ligation (pSNL) markedly increased glial fibrillary acidic protein immunoreactivity (GFAP-IR) 1 week after lesion in the L4-L5 spinal dorsal horn of wild-type, but not in dynorphin knock-out, mice lacking kappa opioid receptors (KOR-/-) or in wild-type mice pretreated with the KOR antagonist nor-binaltorphimine (norBNI). A direct effect of KOR on glial cell proliferation was suggested by the findings that primary cultures of type II GFAP-immunoreactive astrocytes isolated from mouse spinal cord express KOR. Sustained treatment with the kappa agonist U50,488 (trans-3,4-dichloro-N-methyl-N-[2-(1-pyrolytinil)-cyclohexyl]-benzeneacetamide methane sulfonate) significantly increased the proliferation rate of GFAP-immunoreactive astrocytes isolated from wild-type mice, and this effect was blocked by norBNI pretreatment. Proliferation of cultured type II astrocytes may have been stimulated by mitogen-activated protein kinase (MAPK) activation by KOR because (1) U50,488 treatment increased phospho-p38 MAPK-immunoreactivity 247 +/- 44% over untreated cells, (2) the increase in phospho-p38 induced by U50,488 was blocked by norBNI and not evident in KOR-/- cultures, and (3) GFAP-immunoreactive astrocyte proliferation induced by U50,488 was blocked by the p38 MAPK inhibitor SB 203580 [4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)-1H-imidazole]. Similar mechanisms of astrocyte activation may also be responsible in vivo because intrathecal injection of SB 203580 blocked the increased GFAP-IR in lumbar spinal cord induced by pSNL. Although the relationship between kappa-stimulated astrocyte proliferation and neuropathic pain mechanisms was not directly established in these studies, the results support the hypothesis that KOR activation induces spinal astrocyte proliferation, which may contribute to cellular reorganization after sciatic nerve damage.
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MESH Headings
- 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer/pharmacology
- Animals
- Astrocytes/classification
- Astrocytes/cytology
- Astrocytes/metabolism
- Cell Proliferation/drug effects
- Cells, Cultured
- Enzyme Activation/physiology
- Enzyme Inhibitors/pharmacology
- Glial Fibrillary Acidic Protein/metabolism
- Hyperalgesia/etiology
- Hyperalgesia/physiopathology
- Hyperesthesia/etiology
- Hyperesthesia/physiopathology
- Imidazoles/pharmacology
- In Vitro Techniques
- Ligation
- Lumbar Vertebrae
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Naltrexone/analogs & derivatives
- Naltrexone/pharmacology
- Narcotic Antagonists/pharmacology
- Phosphorylation
- Pyridines/pharmacology
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/antagonists & inhibitors
- Receptors, Opioid, kappa/deficiency
- Receptors, Opioid, kappa/physiology
- Sciatic Nerve/surgery
- Spinal Cord/cytology
- Spinal Cord/metabolism
- p38 Mitogen-Activated Protein Kinases/metabolism
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Affiliation(s)
- Mei Xu
- Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington 98195
| | - Michael R. Bruchas
- Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington 98195
| | - Danielle L. Ippolito
- Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington 98195
| | - Louis Gendron
- Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington 98195
| | - Charles Chavkin
- Department of Pharmacology, University of Washington School of Medicine, Seattle, Washington 98195
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46
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Goletiani NV, Mendelson JH, Sholar MB, Siegel AJ, Skupny A, Mello NK. Effects of nalbuphine on anterior pituitary and adrenal hormones and subjective responses in male cocaine abusers. Pharmacol Biochem Behav 2007; 86:667-77. [PMID: 17391744 PMCID: PMC2020834 DOI: 10.1016/j.pbb.2007.02.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2006] [Revised: 02/08/2007] [Accepted: 02/09/2007] [Indexed: 10/23/2022]
Abstract
Nalbuphine (Nubain) is a mixed action mu-kappa agonist used clinically for the management of pain. Nalbuphine and other mu-kappa agonists decreased cocaine self-administration in preclinical models. Cocaine stimulates the hypothalamic-pituitary-adrenal (HPA) axis, but the effects of nalbuphine on the HPA axis are unknown. Analgesic doses (5 and 10 mg/70 kg) of IV nalbuphine were administered to healthy male cocaine abusers, and plasma levels of PRL, ACTH and cortisol were measured before and at 10, 17, 19, 23, 27, 31, 35, 40, 45, 60, 75, 105, and 135 min after nalbuphine administration. Subjective effects were measured on a Visual Analog Scale (VAS). Prolactin (PRL) increased significantly within 17 min (P=.04) and reached peak levels of 22.1+/-7.1 ng/ml and 54.1+/-11.3 at 60 min after low and high dose nalbuphine administration, respectively. VAS reports of "Sick," "Bad" and "Dizzy" were significantly higher after 10 mg/70 kg than after 5 mg/70 kg nalbuphine (P=.05-.0001), and were significantly correlated with increases in PRL (P=.05-.0003). However, sedation and emesis were observed only after a 10 mg/70 kg dose of nalbuphine. Interestingly, ACTH and cortisol levels did not change significantly after administration of either dose of nalbuphine. Taken together, these data suggest that nalbuphine had both mu- and kappa-like effects on PRL (PRL increase) but did not increase ACTH and cortisol.
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MESH Headings
- Adrenal Cortex Hormones/blood
- Adrenocorticotropic Hormone/blood
- Adult
- Cocaine-Related Disorders/drug therapy
- Cocaine-Related Disorders/physiopathology
- Humans
- Hydrocortisone/blood
- Hypothalamo-Hypophyseal System/drug effects
- Hypothalamo-Hypophyseal System/physiopathology
- Male
- Nalbuphine/administration & dosage
- Nalbuphine/adverse effects
- Nalbuphine/blood
- Nalbuphine/pharmacology
- Narcotic Antagonists/administration & dosage
- Narcotic Antagonists/adverse effects
- Narcotic Antagonists/blood
- Narcotic Antagonists/pharmacology
- Pituitary Gland, Anterior/drug effects
- Pituitary Gland, Anterior/physiopathology
- Pituitary-Adrenal System/drug effects
- Pituitary-Adrenal System/physiopathology
- Prolactin/blood
- Receptors, Opioid, kappa/drug effects
- Receptors, Opioid, kappa/physiology
- Receptors, Opioid, mu/drug effects
- Receptors, Opioid, mu/physiology
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Affiliation(s)
- Nathalie V Goletiani
- Alcohol and Drug Abuse Research Center, Harvard Medical School, McLean Hospital, Belmont, MA 02478, USA.
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47
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Pruhs RJ, Peña RT, Quock RM. Antagonism of phosphoramidon-induced antinociception in mice by μ- but not κ-opioid receptor blockers. Life Sci 2007; 80:1816-20. [PMID: 17379253 DOI: 10.1016/j.lfs.2007.02.019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2006] [Revised: 01/27/2007] [Accepted: 02/15/2007] [Indexed: 11/19/2022]
Abstract
Intracerebroventricular (i.c.v.) administration of the neutral endopeptidase 24.11-inhibitor phosphoramidon evoked a dose-dependent antinociceptive effect in the mouse acetic acid abdominal constriction test. The present study was conducted to identify the opioid receptor subtype(s) that mediate phosphoramidon antinociception in this paradigm. Mice were pretreated with different opioid antagonists prior to being challenged with phosphoramidon, i.c.v., the mu-opioid agonist sufentanil, s.c., or the kappa-opioid agonist U-50,488H, s.c. Naltrexone significantly attenuated phosphoramidon-induced antinociception at an i.c.v. dose that also blocked both sufentanil and U-50,488H. The mu-opioid antagonist beta-funaltrexamine (beta-FNA) blocked phosphoramidon and sufentanil at an i.c.v. dose that did not block U-50,488H. The kappa-opioid antagonist nor-binaltorphimine (nor-BNI) produced dose-related effects. A low dose (10 microg) of nor-BNI had no effect on either phosphoramidon or sufentanil but did reduce U-50,488H antinociception. A higher dose (30 microg) of nor-BNI blocked phosphoramidon, sufentanil, and U-50,488H, suggesting a loss of kappa-opioid receptor selectivity at this dose. These findings suggest that mu- but not kappa-opioid receptors mediate phosphoramidon-induced antinociception in the abdominal constriction test.
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MESH Headings
- 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer/pharmacology
- Analgesia
- Animals
- Glycopeptides/antagonists & inhibitors
- Glycopeptides/pharmacology
- Male
- Mice
- Mice, Inbred ICR
- Naltrexone/analogs & derivatives
- Naltrexone/pharmacology
- Narcotic Antagonists/pharmacology
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/antagonists & inhibitors
- Receptors, Opioid, kappa/physiology
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/antagonists & inhibitors
- Receptors, Opioid, mu/physiology
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Affiliation(s)
- Ronald J Pruhs
- Department of Pediatric Dentistry, Marquette University School of Dentistry, Milwaukee, WI 53201-1881, United States
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48
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Loacker S, Sayyah M, Wittmann W, Herzog H, Schwarzer C. Endogenous dynorphin in epileptogenesis and epilepsy: anticonvulsant net effect via kappa opioid receptors. ACTA ACUST UNITED AC 2007; 130:1017-28. [PMID: 17347252 DOI: 10.1093/brain/awl384] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Neuropsychiatric disorders are one of the main challenges of human medicine with epilepsy being one of the most common serious disorders of the brain. Increasing evidence suggest neuropeptides, particularly the opioids, play an important role in epilepsy. However, little is known about the mechanisms of the endogenous opioid system in epileptogenesis and epilepsy. Therefore, we investigated the role of endogenous prodynorphin-derived peptides in epileptogenesis, acute seizure behaviour and epilepsy in prodynorphin-deficient mice. Compared with wild-type littermates, prodynorphin knockout mice displayed a significantly reduced seizure threshold as assessed by tail-vein infusion of the GABA(A) antagonist pentylenetetrazole. This phenotype could be entirely rescued by the kappa receptor-specific agonist U-50488, but not by the mu receptor-specific agonist DAMGO. The delta-specific agonist SNC80 decreased seizure threshold in both genotypes, wild-type and knockout. Pre-treatment with the kappa selective antagonist GNTI completely blocked the rescue effect of U-50488. Consistent with the reduced seizure threshold, prodynorphin knockout mice showed faster seizure onset and a prolonged time of seizure activity after intracisternal injection of kainic acid. Three weeks after local injection of kainic acid into the stratum radiatum CA1 of the dorsal hippocampus, prodynorphin knockout mice displayed an increased extent of granule cell layer dispersion and neuronal loss along the rostrocaudal axis of the ipsi- and partially also of the contralateral hippocampus. In the classical pentylenetetrazole kindling model, dynorphin-deficient mice showed significantly faster kindling progression with six out of eight animals displaying clonic seizures, while none of the nine wild-types exceeded rating 3 (forelimb clonus). Taken together, our data strongly support a critical role for dynorphin in the regulation of hippocampal excitability, indicating an anticonvulsant role of kappa opioid receptors, thereby providing a potential target for antiepileptic drugs.
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MESH Headings
- 3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-Isomer/pharmacology
- Analgesics/pharmacology
- Animals
- Benzamides/pharmacology
- Cell Count
- Enkephalin, Ala(2)-MePhe(4)-Gly(5)-/pharmacology
- Enkephalins/genetics
- Enkephalins/metabolism
- Enkephalins/physiology
- Epilepsy, Temporal Lobe/metabolism
- Epilepsy, Temporal Lobe/physiopathology
- Guanidines
- Hippocampus/metabolism
- Kindling, Neurologic/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Morphinans
- Naltrexone/analogs & derivatives
- Naltrexone/pharmacology
- Nerve Degeneration/metabolism
- Piperazines/pharmacology
- Protein Precursors/genetics
- Protein Precursors/metabolism
- Protein Precursors/physiology
- Receptors, Opioid, kappa/agonists
- Receptors, Opioid, kappa/antagonists & inhibitors
- Receptors, Opioid, kappa/physiology
- Synaptic Transmission/physiology
- Time Factors
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Affiliation(s)
- Stephan Loacker
- Department of Pharmacology, Innsbruck Medical University, Innsbruck, Austria
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49
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Sandrini M, Vitale G, Ruggieri V, Pini LA. Effect of acute and repeated administration of paracetamol on opioidergic and serotonergic systems in rats. Inflamm Res 2007; 56:139-42. [PMID: 17522810 DOI: 10.1007/s00011-006-6113-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVE AND DESIGN We investigated the antinociceptive effect of paracetamol or morphine after repeated administration and the changes in the characteristics of central mu-, kappa- and 5-HT2 receptors. TREATMENT Male rats were injected twice a day for seven days with paracetamol (400 mg/kg, i. p.) or morphine (5 mg/kg, s. c.). METHODS The antinociceptive effect was evaluated 30 min after single and multiple doses of paracetamol and morphine through the hot-plate test. Binding techniques were used to evaluate the receptor characteristics in the frontal cortex. RESULTS Both paracetamol and morphine induced an antinociceptive effect on day 1 but only paracetamol maintained this effect for seven days while morphine did not. The number of mu-opioid receptors decreased on days 1, 3, and 7 by a similar percentage after paracetamol administration (by 29, 31 and 34 %, respectively), while morphine produced a progressive decrease in comparison with controls (by 37, 49 and 60 %, respectively) and kappa-opioid receptors were unaffected. Both drugs similarly decreased the 5-HT2 receptor number on all days of treatment (by about 30 %). CONCLUSIONS The opioidergic and serotonergic systems are involved in different ways in the induction and maintenance of antinociception after paracetamol or morphine treatment.
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MESH Headings
- Acetaminophen/pharmacology
- Analgesics, Non-Narcotic/pharmacology
- Animals
- Dose-Response Relationship, Drug
- Frontal Lobe/drug effects
- Frontal Lobe/physiology
- Male
- Morphine/pharmacology
- Narcotics/pharmacology
- Neurons/drug effects
- Neurons/physiology
- Random Allocation
- Rats
- Rats, Wistar
- Receptors, Opioid/drug effects
- Receptors, Opioid/physiology
- Receptors, Opioid, kappa/drug effects
- Receptors, Opioid, kappa/physiology
- Receptors, Opioid, mu/drug effects
- Receptors, Opioid, mu/physiology
- Receptors, Serotonin/drug effects
- Receptors, Serotonin/physiology
- Receptors, Serotonin, 5-HT2/drug effects
- Receptors, Serotonin, 5-HT2/physiology
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Affiliation(s)
- M Sandrini
- Department of Biomedical Sciences, Sec. of Pharmacology, University of Modena and Reggio Emilia, Via G. Campi, 287-41100, Modena, Italia.
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50
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Stoller DC, Sim-Selley LJ, Smith FL. Role of kappa and delta opioid receptors in mediating morphine-induced antinociception in morphine-tolerant infant rats. Brain Res 2007; 1142:28-36. [PMID: 17300766 PMCID: PMC3159155 DOI: 10.1016/j.brainres.2007.01.028] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2006] [Revised: 12/21/2006] [Accepted: 01/09/2007] [Indexed: 11/21/2022]
Abstract
We have previously noted that the antinociceptive efficacy of morphine was significantly decreased in rat pups chronically infused with morphine from implanted osmotic minipumps. In this study, morphine was fully efficacious (i.e., 100% maximum possible effect, %MPE) in the 52 degrees C tail-immersion test after a 72-h infusion from implanted saline-filled osmotic minipumps. However, administration of up to 1000 mg/kg, s.c. morphine failed to elicit greater than a 27% MPE in rats infused with morphine at 2 mg/kg/h. Morphine was more efficacious when the water bath temperature was decreased to 49 degrees C. Experiments were conducted to determine the mechanisms whereby chronic morphine administration leads to a decrease in antinociceptive efficacy. The kappa-opioid antagonist nor-binalorphimine completely blocked the antinociceptive effects of morphine in morphine-infused rat pups. The kappa agonist U50,488 elicited antinociception; however, the requirement to use higher doses in morphine- than saline-infused rats indicates that kappa cross-tolerance was present. Thus, in tolerant rats the antinociceptive effects of high doses of morphine appear to be mediated through kappa-opioid receptors. The delta-opioid antagonist naltrindole was inactive in both treatment groups. DAMGO-stimulated [(35)S]GTPgammaS and [(3)H]naloxone binding reveals that the anatomical distribution of the mu-opioid receptor was consistent with that of the adult rat brain. In adult rats, the mu-opioid receptor is desensitized during morphine tolerance. However, desensitization was not evident in P17 rats based on the lack of significant decreases in [(35)S]GTPgammaS binding. Furthermore, [(3)H]naloxone binding indicated a lack of mu receptor downregulation in morphine-tolerant rat pups.
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Affiliation(s)
- Dawn C Stoller
- Department of Pharmacology and Toxicology, Virginia Commonwealth University Medical Center, PO Box 980613, Richmond, VA 23298-0613, USA
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