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Wang A, Shulman M, Choo T, Pavlicova M, Langleben DD, Nunes EV, Rotrosen J. Baseline- and treatment-associated pain in the X:BOT comparative effectiveness study of extended-release naltrexone versus buprenorphine-naloxone for OUD. Addict Biol 2022; 27:e13112. [PMID: 34877769 DOI: 10.1111/adb.13112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 10/06/2021] [Accepted: 10/20/2021] [Indexed: 11/30/2022]
Abstract
Chronic pain is highly prevalent among patients with opioid use disorder (OUD). However, little is known about how pharmacological treatments for OUD, for example, extended-release naltrexone (XR-NTX) and buprenorphine-naloxone (BUP-NX), affect pain. To begin addressing this question, we performed a secondary analysis of pain data on a large prospective 24-week, open-label, randomized-controlled comparative effectiveness trial of XR-NTX versus BUP-NX (X:BOT trial). Participants' pain status was measured by the EuroQol (EQ-5D). Based on their responses to the pain question at baseline, participants were dichotomized into "Pain" versus "No Pain" categories. Participant's pain status was evaluated every 4 weeks. A mixed effects longitudinal logistic regression model was fitted to examine the differential effect of XR-NTX versus BUP-NX on pain, modelling pain at all available follow-up assessments, adjusted for age, sex, and baseline pain. A total of 474 individuals who were successfully inducted onto their assigned medications were included in this analysis. Among participants endorsing pain at baseline, substantial reductions in pain were observed over the course of the study in both treatment groups. Howecver reduction in pain was slightly greater in the group treated with XR-NTX than the one treated with BUP-NX (OR = 1.60 [95% CI: 1.07-2.40], P = 0.023). Future research using instruments and design specifically focused on pain could extend the present observations and evaluate their clinical significance.
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Affiliation(s)
- An‐Li Wang
- Addiction Institute of Mount Sinai, Department of Psychiatry Icahn School of Medicine at Mount Sinai New York New York USA
| | - Matisyahu Shulman
- Department of Psychiatry Columbia University Irving Medical Center and New York State Psychiatric Institute New York New York USA
| | - Tse‐Hwei Choo
- Department of Psychiatry Columbia University Irving Medical Center and New York State Psychiatric Institute New York New York USA
| | - Martina Pavlicova
- Department of Biostatistics Columbia University Mailman School of Public Health New York New York USA
| | - Daniel D. Langleben
- Department of Psychiatry University of Pennsylvania Perelman School of Medicine Philadelphia Pennsylvania USA
| | - Edward V. Nunes
- Department of Psychiatry Columbia University Irving Medical Center and New York State Psychiatric Institute New York New York USA
| | - John Rotrosen
- Department of Psychiatry NYU Grossman School of Medicine New York New York USA
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Llorca-Torralba M, Pilar-Cuéllar F, da Silva Borges G, Mico JA, Berrocoso E. Opioid receptors mRNAs expression and opioids agonist-dependent G-protein activation in the rat brain following neuropathy. Prog Neuropsychopharmacol Biol Psychiatry 2020; 99:109857. [PMID: 31904442 DOI: 10.1016/j.pnpbp.2019.109857] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 12/24/2019] [Accepted: 12/31/2019] [Indexed: 12/12/2022]
Abstract
Potent opioid-based therapies are often unsuccessful in promoting satisfactory analgesia in neuropathic pain. Moreover, the side effects associated with opioid therapy are still manifested in neuropathy-like diseases, including tolerance, abuse, addiction and hyperalgesia, although the mechanisms underlying these effects remain unclear. Studies in the spinal cord and periphery indicate that neuropathy alters the expression of mu-[MOP], delta-[DOP] or kappa-[KOP] opioid receptors, interfering with their activity. However, there is no consensus as to the supraspinal opioidergic modulation provoked by neuropathy, the structures where the sensory and affective-related pain components are processed. In this study we explored the effect of chronic constriction of the sciatic nerve (CCI) over 7 and 30 days (CCI-7d and CCI-30d, respectively) on MOP, DOP and KOP mRNAs expression, using in situ hybridization, and the efficacy of G-protein stimulation by DAMGO, DPDPE and U-69593 (MOP, DOP and KOP specific agonists, respectively), using [35S]GTPγS binding, within opioid-sensitive brain structures. After CCI-7d, CCI-30d or both, opioid receptor mRNAs expression was altered throughout the brain: MOP - in the paracentral/centrolateral thalamic nuclei, ventral posteromedial thalamic nuclei, superior olivary complex, parabrachial nucleus [PB] and posterodorsal tegmental nucleus; DOP - in the somatosensory cortex [SSC], ventral tegmental area, caudate putamen [CPu], nucleus accumbens [NAcc], raphe magnus [RMg] and PB; and KOP - in the locus coeruleus. Agonist-stimulated [35S]GTPγS binding was altered following CCI: MOP - CPu and RMg; DOP - prefrontal cortex [PFC], SSC, RMg and NAcc; and KOP - PFC and SSC. Thus, this study shows that several opioidergic circuits in the brain are recruited and modified following neuropathy.
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Affiliation(s)
- Meritxell Llorca-Torralba
- Neuropsychopharmacology and Psychobiology Research Group, Department of Neuroscience, University of Cádiz, Cádiz, Spain; Biomedical Research Networking Center for Mental Health Network (CIBERSAM), Institute of Health Carlos III, Madrid, Spain; Biomedical Research and Innovation Institute of Cádiz (INiBICA) Research Unit, Puerta del Mar University Hospital, University of Cádiz, Cádiz, Spain
| | - Fuencisla Pilar-Cuéllar
- Biomedical Research Networking Center for Mental Health Network (CIBERSAM), Institute of Health Carlos III, Madrid, Spain; Instituto de Biomedicina y Biotecnología de Cantabria, IBBTEC (Universidad de Cantabria, CSIC, SODERCAN), Department of Physiology and Pharmacology, University of Cantabria, Santander, Spain
| | | | - Juan A Mico
- Neuropsychopharmacology and Psychobiology Research Group, Department of Neuroscience, University of Cádiz, Cádiz, Spain; Biomedical Research Networking Center for Mental Health Network (CIBERSAM), Institute of Health Carlos III, Madrid, Spain; Biomedical Research and Innovation Institute of Cádiz (INiBICA) Research Unit, Puerta del Mar University Hospital, University of Cádiz, Cádiz, Spain
| | - Esther Berrocoso
- Biomedical Research Networking Center for Mental Health Network (CIBERSAM), Institute of Health Carlos III, Madrid, Spain; Biomedical Research and Innovation Institute of Cádiz (INiBICA) Research Unit, Puerta del Mar University Hospital, University of Cádiz, Cádiz, Spain; Neuropsychopharmacology and Psychobiology Research Group, Department of Psychology, University of Cádiz, Cádiz, Spain.
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3
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Younger J, Noor N, McCue R, Mackey S. Low-dose naltrexone for the treatment of fibromyalgia: findings of a small, randomized, double-blind, placebo-controlled, counterbalanced, crossover trial assessing daily pain levels. ACTA ACUST UNITED AC 2013; 65:529-38. [PMID: 23359310 DOI: 10.1002/art.37734] [Citation(s) in RCA: 119] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2012] [Accepted: 09/27/2012] [Indexed: 12/19/2022]
Abstract
OBJECTIVE To determine whether low dosages (4.5 mg/day) of naltrexone reduce fibromyalgia severity as compared with the nonspecific effects of placebo. In this replication and extension study of a previous clinical trial, we tested the impact of low-dose naltrexone on daily self-reported pain. Secondary outcomes included general satisfaction with life, positive mood, sleep quality, and fatigue. METHODS Thirty-one women with fibromyalgia participated in the randomized, double-blind, placebo-controlled, counterbalanced, crossover study. During the active drug phase, participants received 4.5 mg of oral naltrexone daily. An intensive longitudinal design was used to measure daily levels of pain. RESULTS When contrasting the condition end points, we observed a significantly greater reduction of baseline pain in those taking low-dose naltrexone than in those taking placebo (28.8% reduction versus 18.0% reduction; P = 0.016). Low-dose naltrexone was also associated with improved general satisfaction with life (P = 0.045) and with improved mood (P = 0.039), but not improved fatigue or sleep. Thirty-two percent of participants met the criteria for response (defined as a significant reduction in pain plus a significant reduction in either fatigue or sleep problems) during low-dose naltrexone therapy, as contrasted with an 11% response rate during placebo therapy (P = 0.05). Low-dose naltrexone was rated equally tolerable as placebo, and no serious side effects were reported. CONCLUSION The preliminary evidence continues to show that low-dose naltrexone has a specific and clinically beneficial impact on fibromyalgia pain. The medication is widely available, inexpensive, safe, and well-tolerated. Parallel-group randomized controlled trials are needed to fully determine the efficacy of the medication.
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Affiliation(s)
- Jarred Younger
- Stanford University School of Medicine, Palo Alto, California 94304-1573, USA.
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Chechneva OV, Mayrhofer F, Daugherty DJ, Pleasure DE, Hong JS, Deng W. Low dose dextromethorphan attenuates moderate experimental autoimmune encephalomyelitis by inhibiting NOX2 and reducing peripheral immune cells infiltration in the spinal cord. Neurobiol Dis 2011; 44:63-72. [PMID: 21704706 DOI: 10.1016/j.nbd.2011.06.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Revised: 05/28/2011] [Accepted: 06/10/2011] [Indexed: 11/24/2022] Open
Abstract
Dextromethorphan (DM) is a dextrorotary morphinan and a widely used component of cough medicine. Relatively high doses of DM in combination with quinidine are used for the treatment of mood disorders for patients with multiple sclerosis (MS). However, at lower doses, morphinans exert anti-inflammatory activities through the inhibition of NOX2-dependent superoxide production in activated microglia. Here we investigated the effects of high (10 mg/kg, i.p., "DM-10") and low (0.1 mg/kg, i.p., "DM-0.1") doses of DM on the development and progression of mouse experimental autoimmune encephalomyelitis (EAE), an animal model of MS. We found no protection by high dose DM treatment. Interestingly, a minor late attenuation by low dose DM treatment was seen in severe EAE that was characterized by a chronic disease course and a massive spinal cord infiltration of CD45(+) cells including T-lymphocytes, macrophages and neutrophils. Furthermore, in a less severe form of EAE, where lower levels of CD4(+) and CD8(+) T-cells, Iba1(+) microglia/macrophages and no significant infiltration of neutrophils were seen in the spinal cord, the treatment with DM-0.1 was remarkably more beneficial. The effect was the most significant at the peak of disease and was associated with an inhibition of NOX2 expression and a decrease in infiltration of monocytes and lymphocytes into the spinal cord. In addition, chronic treatment with low dose DM resulted in decreased demyelination and reduced axonal loss in the lumbar spinal cord. Our study is the first report to show that low dose DM is effective in treating EAE of moderate severity. Our findings reveal that low dose morphinan DM treatment may represent a new promising protective strategy for treating MS.
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Affiliation(s)
- Olga V Chechneva
- Department of Cell Biology and Human Anatomy, School of Medicine, University of California-Davis, 2425 Stockton Blvd, Sacramento, 95817 CA, USA
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Onoprishvili I, Simon EJ. Chronic morphine treatment up-regulates mu opioid receptor binding in cells lacking filamin A. Brain Res 2007; 1177:9-18. [PMID: 17897634 PMCID: PMC2175075 DOI: 10.1016/j.brainres.2007.08.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2007] [Revised: 05/31/2007] [Accepted: 08/09/2007] [Indexed: 11/19/2022]
Abstract
We investigated the effects of morphine and other agonists on the human mu opioid receptor (MOP) expressed in M2 melanoma cells, lacking the actin cytoskeleton protein filamin A and in A7, a subclone of the M2 melanoma cells, stably transfected with filamin A cDNA. The results of binding experiments showed that after chronic morphine treatment (24 h) of A7 cells, MOP-binding sites were down-regulated to 63% of control, whereas, unexpectedly, in M2 cells, MOP binding was up-regulated to 188% of control naive cells. Similar up-regulation was observed with the agonists methadone and levorphanol. The presence of antagonists (naloxone or CTAP) during chronic morphine treatment inhibited MOP down-regulation in A7 cells. In contrast, morphine-induced up-regulation of MOP in M2 cells was further increased by these antagonists. Chronic morphine desensitized MOP in A7 cells, i.e., it decreased DAMGO-induced stimulation of GTPgammaS binding. In M2 cells DAMGO stimulation of GTPgammaS binding was significantly greater than in A7 cells and was not desensitized by chronic morphine. Pertussis toxin treatment abolished morphine-induced receptor up-regulation in M2 cells, whereas it had no effect on morphine-induced down-regulation in A7 cells. These results indicate that, in the absence of filamin A, chronic treatment with morphine, methadone or levorphanol leads to up-regulation of MOP, to our knowledge, the first instance of opioid receptor up-regulation by agonists in cell culture.
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MESH Headings
- Blotting, Western
- Cell Line
- Cell Line, Tumor
- Contractile Proteins/deficiency
- Contractile Proteins/physiology
- Data Interpretation, Statistical
- Diprenorphine/pharmacology
- Enkephalin, Ala(2)-MePhe(4)-Gly(5)-/pharmacology
- Filamins
- Guanosine 5'-O-(3-Thiotriphosphate)/metabolism
- Humans
- Ligands
- Melanoma/genetics
- Melanoma/pathology
- Microfilament Proteins/deficiency
- Microfilament Proteins/physiology
- Morphine/pharmacology
- Narcotic Antagonists/metabolism
- Narcotic Antagonists/pharmacology
- Narcotics/pharmacology
- Pertussis Toxin/pharmacology
- Radioligand Assay
- Receptors, Opioid, mu/agonists
- Receptors, Opioid, mu/drug effects
- Receptors, Opioid, mu/metabolism
- Tubulin/pharmacology
- Up-Regulation/drug effects
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Affiliation(s)
- Irma Onoprishvili
- Department of Psychiatry, New York University School of Medicine, New York, NY
| | - Eric J. Simon
- Department of Psychiatry, New York University School of Medicine, New York, NY
- Department of Pharmacology, New York University School of Medicine, New York, NY
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Puppala BL, Bhalla S, Matwyshyn G, Gulati A. Role of endothelin (ETA) receptors in neonatal morphine withdrawal. Peptides 2006; 27:1514-9. [PMID: 16293342 DOI: 10.1016/j.peptides.2005.10.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2005] [Revised: 10/14/2005] [Accepted: 10/14/2005] [Indexed: 11/21/2022]
Abstract
We have previously demonstrated role of central endothelin (ET) receptors in neonatal morphine tolerance. The present study was conducted to investigate involvement of central ET receptors in neonatal rat morphine withdrawal. The aim was to determine activation of G-proteins coupled to opioid and ET receptors by morphine and ET ligands in neonatal rat brains during morphine withdrawal. Pregnant female rats were rendered tolerant to morphine by chronic exposure to morphine pellets over 7 days. Withdrawal was induced on day 8 by removal of pellets. Rat pups were delivered by cesarean section 24 h after pellet removal. G-protein stimulation induced by morphine; ET-1; ETA receptor antagonist, BMS182874; and ETB receptor agonist, IRL1620, was determined in the brain of neonatal rats undergoing morphine withdrawal by [35S]GTPgammaS binding assay. Morphine-induced maximal stimulation of G-protein in morphine withdrawal group (83.60%) was significantly higher compared to placebo control group (66.81%). EC50 value for ET-1-induced G-protein stimulation during morphine withdrawal (170.60 nM) was higher than control (62.5 nM). BMS182874, did not stimulate GTP binding in control but significantly increased maximal stimulation of G-proteins in morphine withdrawal (86.07%, EC50 = 31.25 nM). IRL1620-induced stimulation of G-proteins was similar in control and morphine withdrawal. The present findings indicate involvement of central ETA receptors in neonatal morphine withdrawal.
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Affiliation(s)
- Bhagya L Puppala
- Department of Pediatrics and Neonatology, Advocate Lutheran General Children's Hospital, Park Ridge, IL 60068, USA
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7
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Bhalla S, Matwyshyn G, Gulati A. Morphine tolerance does not develop in mice treated with endothelin-A receptor antagonists. Brain Res 2005; 1064:126-35. [PMID: 16289404 DOI: 10.1016/j.brainres.2005.09.054] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2005] [Revised: 09/05/2005] [Accepted: 09/24/2005] [Indexed: 10/25/2022]
Abstract
Long-term use of morphine leads to development of antinociceptive tolerance. We provide evidence that central endothelin (ET) mechanisms are involved in development of morphine tolerance. In the present study, we investigated the effect of ET(A) receptor antagonists, BQ123 and BMS182874, on morphine antinociception and tolerance in mice. Mechanism of interaction of ET(A) receptor antagonists with morphine was investigated. BQ123 (3 microg, i.c.v.) and BMS182874 (50 microg, i.c.v.) significantly enhanced antinociceptive effect of morphine (P < 0.05), through an opioid-mediated effect. Treatment with a single dose of BQ123 (3 microg, i.c.v.) reversed tolerance to morphine antinociception in morphine-tolerant mice. BQ123 or BMS182874 did not affect naloxone binding in the brain. Therefore, ET(A) receptor antagonists did not bind directly to opioid receptors. [35S]GTPgammaS binding was stimulated by morphine and ET-1 in non-tolerant mice. Morphine- and ET-1-induced GTP stimulation was significantly lower (P < 0.05) in morphine-tolerant group (33% and 42%, respectively) compared to control group. BQ123 and BMS182874 did not activate binding in non-tolerant mice. BQ123 and BMS182874 significantly increased G protein activation in morphine-tolerant mice (96% and 86%, respectively; P < 0.05). These results provide evidence that uncoupling of G protein occurs in morphine-tolerant mice, and ET(A) antagonists promote coupling of G protein to its receptors, thereby restoring antinociceptive effect. These findings indicate that ET(A) receptor antagonists potentiate morphine antinociception and reverse antinociceptive tolerance in mice, through their ability to couple G proteins to opioid receptors.
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Affiliation(s)
- Shaifali Bhalla
- Department of Biopharmaceutical Sciences (M/C 865), University of Illinois at Chicago, 833 South Wood Street, Chicago, IL 60612, USA
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8
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Puppala BL, Matwyshyn G, Bhalla S, Gulati A. Evidence that morphine tolerance may be regulated by endothelin in the neonatal rat. Neonatology 2004; 86:138-44. [PMID: 15218283 DOI: 10.1159/000079272] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2004] [Accepted: 04/20/2004] [Indexed: 11/19/2022]
Abstract
BACKGROUND Opioids are widely used in the neonatal intensive care units for analgesia and sedation. Management of tolerance and withdrawal symptoms in neonates remains a major challenge. OBJECTIVES The present study investigates the involvement of a central endothelin (ET) mechanism in the development of tolerance to morphine in neonatal rats. METHODS Pregnant female rats were rendered tolerant to morphine and rat pups were delivered at term by cesarean section. The affinity (Kd) and density (Bmax) of ET receptors was determined by [125I]ET-1 binding in the brains of neonatal rats. Changes in G-protein stimulation were determined in placebo and morphine-tolerant neonatal rats by [35S]-guanosine-5'-o-(3-thio)triphosphate ([35S]GTPgammaS)-binding assay. RESULTS Morphine tolerance did not affect the characteristics (affinity and density) of the ET receptors in the neonatal rat brains. Morphine as well as ET-1 produced significantly lower (p < 0.05) maximal stimulation of [35S]GTPgammaS binding in morphine-tolerant neonatal rats compared to the placebo group. The ETA receptor antagonist, BMS182874, produced significantly higher stimulation of G proteins in the morphine-tolerant compared to the placebo group. The ETB receptor agonist, IRL1620, produced a similar effect in both placebo and morphine-tolerant rats. CONCLUSIONS This is the first report indicating the involvement of the G-protein-coupled ETA receptor in neonatal morphine tolerance.
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Affiliation(s)
- Bhagya L Puppala
- Department of Pediatrics and Neonatology, Advocate Lutheran General Children's Hospital, Park Ridge, IL, USA
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9
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Abstract
Although far from conclusive, evidence implicating the endogenous opioid system in the development and maintenance of alcoholism is growing. Currently available data suggest that ethanol increases opioid neurotransmission and that this activation is part of the mechanism responsible for its reinforcing effects. Findings from preclinical research indicate that ethanol consumption and ethanol-induced dopamine (DA) release are both reduced by opioid antagonists. Individual differences in endogenous opioid activity have been linked to inherited risks for alcoholism in studies comparing ethanol-preferring and nonpreferring rats, as well as in studies using targeted gene mutation (knockout) strategies. To a large extent, findings from human studies have paralleled those from the preclinical work. Persons who differ in family history of alcoholism have been shown to also differ in basal beta-endorphin activity, beta-endorphin response to alcohol, and subjective and HPA axis hormonal response to opioid antagonists. Findings from clinical trials indicate that opioid antagonists may reduce ethanol consumption in alcoholics, particularly in persons who have resumed drinking. Nevertheless, many questions remain unanswered about the use of opioid antagonists in alcoholism treatment and about the exact role of the opioid system in ethanol preference and reward. The progression of knowledge in this field suggests that many of these questions are imminently answerable, as our ability to characterize relationships between opioid activity and human behavior continues to develop. This paper summarizes both the progress that has been made and the gaps that remain in our understanding of the interactions between the endogenous opioid system and risk for alcoholism.
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Affiliation(s)
- L M Oswald
- Departments of Medicine and Psychiatry, The Johns Hopkins University, School of Medicine, Ross Research Building, Room 863, 720 Rutland Avenue, Baltimore, MD 21205, USA
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Narita M, Suzuki M, Mizoguchi H, Narita M, Yajima Y, Sakurada S, Tseng LF, Suzuki T. Up-regulation of mu-opioid receptor-mediated G-protein activation in protein kinase Cgamma knockout mice following repeated naloxone treatment. Neurosci Lett 2003; 338:103-6. [PMID: 12566163 DOI: 10.1016/s0304-3940(02)01354-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The aim of the present study was to investigate whether repeated treatment with the mu-opioid receptor antagonist naloxone could affect G-protein activation induced by a selective mu-opioid receptor agonist [D-Ala(2),N-MePhe(4),Gly-ol(5)]enkephalin (DAMGO) in mice lacking the protein kinase Cgamma isoform monitoring guanosine-5'-o-(3-[(35)S]thio)triphosphate ([(35)S]GTPgammaS) binding. Repeated s.c. administration of naloxone for 7 days resulted in a significant enhancement of the increased [(35)S]GTPgammaS binding by DAMGO to membranes of the spinal cord obtained from mice lacking the protein kinase Cgamma isoform. Furthermore, immunoreactivities of membrane-located protein kinase Cgamma and phosphorylated-protein kinase C in the spinal cord of ICR mice were not altered by repeated naloxone treatment. The present data provide direct evidence that protein kinase Cgamma is not involved in the development of the up-regulation of mu-opioid receptor functions to activate G-proteins in the mouse spinal cord by repeated naloxone treatment.
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Affiliation(s)
- Minoru Narita
- Department of Toxicology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, 2-4-41 Ebara, Shinagawa-ku, 142-8501, Tokyo, Japan
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Abstract
This paper is the twenty-fourth installment of the annual review of research concerning the opiate system. It summarizes papers published during 2001 that studied the behavioral effects of the opiate peptides and antagonists. The particular topics covered this year include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology(Section 9); mental illness and mood (Section 10); seizures and neurologic disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, CUNY, 65-30 Kissena Blvd., Flushing, NY 11367, USA.
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