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Anversa RG, Barron ML, Walker LC, Lawrence AJ. Emerging GPCR targets for AUD: Insights from preclinical studies. Curr Opin Neurobiol 2024; 87:102896. [PMID: 38971113 DOI: 10.1016/j.conb.2024.102896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2024] [Revised: 06/13/2024] [Accepted: 06/13/2024] [Indexed: 07/08/2024]
Abstract
G protein-coupled receptors (GPCRs) are the largest group of membrane receptors in the central nervous system and one of the key proteins for signal transduction between cells. Currently, many drugs available on the market act via GPCRs and these receptors remain attractive targets for the treatment of brain disorders, including alcohol use disorder (AUD). Here, we describe the most recent literature, with a primary focus on the past 5 years, on GPCR targets with the potential for reducing behaviours associated with excessive alcohol intake. Specifically, we focus on preclinical evidence of compounds with attractive pharmacological profiles and potential for future clinical investigation for the treatment of AUD.
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Affiliation(s)
- Roberta Goncalves Anversa
- Florey Institute of Neuroscience and Mental Health, Melbourne 3052, Australia; Florey Department of Neuroscience and Mental Health, University of Melbourne, Melbourne 3052, Australia
| | - Maiya L Barron
- Florey Institute of Neuroscience and Mental Health, Melbourne 3052, Australia; School of Biomedical Sciences, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Leigh C Walker
- Florey Institute of Neuroscience and Mental Health, Melbourne 3052, Australia; Florey Department of Neuroscience and Mental Health, University of Melbourne, Melbourne 3052, Australia
| | - Andrew J Lawrence
- Florey Institute of Neuroscience and Mental Health, Melbourne 3052, Australia; Florey Department of Neuroscience and Mental Health, University of Melbourne, Melbourne 3052, Australia.
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2
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Colombo G. Positive allosteric modulators of the GABAB receptor: a new class of ligands with therapeutic potential for alcohol use disorder. Alcohol Alcohol 2024; 59:agae018. [PMID: 38566580 DOI: 10.1093/alcalc/agae018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 02/22/2024] [Accepted: 03/08/2024] [Indexed: 04/04/2024] Open
Abstract
BACKGROUND Positive allosteric modulators (PAMs) of the GABAB receptor constitute a new class of GABAB-receptor ligands. GABAB PAMs reproduce several pharmacological effects of the orthosteric GABAB receptor agonist, baclofen, although displaying a better safety profile. AIMS This paper reviews the reducing or, frequently, even suppressing effects of all GABAB PAMs tested to date on multiple alcohol-related behaviours in laboratory rodents exposed to validated experimental models of human alcohol use disorder. RESULTS Acute or repeated treatment with CGP7930, GS39783, BHF177, rac-BHFF, ADX71441, CMPPE, COR659, ASP8062, KK-92A, and ORM-27669 reduced excessive alcohol drinking, relapse- and binge-like drinking, operant alcohol self-administration, reinstatement of alcohol seeking, and alcohol-induced conditioned place preference in rats and mice. CONCLUSIONS These effects closely mirrored those of baclofen; notably, they were associated to remarkably lower levels of tolerance and toxicity. The recent transition of ASP8062 to clinical testing will soon prove whether these highly consistent preclinical data translate to AUD patients.
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Affiliation(s)
- Giancarlo Colombo
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, I-09042, Monserrato (CA), Italy
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Maccioni P, Kaczanowska K, Lobina C, Regonini Somenzi L, Bassareo V, Gessa GL, Lawrence HR, McDonald P, Colombo G. Delving into the reducing effects of the GABA B positive allosteric modulator, KK-92A, on alcohol-related behaviors in rats. Alcohol 2023; 112:61-70. [PMID: 37495087 DOI: 10.1016/j.alcohol.2023.07.004] [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: 04/24/2023] [Revised: 06/26/2023] [Accepted: 07/20/2023] [Indexed: 07/28/2023]
Abstract
Recent studies have demonstrated the ability of the positive allosteric modulator (PAM) of the GABAB receptor (GABAB PAM), KK-92A, to suppress operant alcohol self-administration and reinstatement of alcohol seeking in selectively bred Sardinian alcohol-preferring (sP) rats. The present study was designed to scrutinize the suppressing effects of KK-92A on alcohol-related behaviors; to this end, four separate experiments were conducted to address just as many new research questions, some of which bear translational value. Experiment 1 found that 7-day treatment with KK-92A (0, 5, 10, and 20 mg/kg, intraperitoneally [i.p.]) effectively reduced alcohol intake in male sP rats exposed to the home-cage 2-bottle "alcohol (10% v/v) vs. water" choice regimen with 1 hour/day limited access, extending to excessive alcohol drinking the ability of KK-92A to suppress operant alcohol self-administration. Experiment 2 demonstrated that the ability of KK-92A to reduce lever-responding for alcohol was maintained also after acute, intragastric treatment (0, 20, and 40 mg/kg) in female sP rats trained to lever-respond for 15% (v/v) alcohol under the fixed ratio 5 schedule of reinforcement. In Experiment 3, acutely administered KK-92A (0, 5, 10, and 20 mg/kg, i.p.) dampened alcohol-seeking behavior in female sP rats exposed to a single session under the extinction responding schedule. Experiment 4 used a taste reactivity test to demonstrate that acute treatment with KK-92A (0 and 20 mg/kg, i.p.) did not alter either hedonic or aversive reactions to a 15% (v/v) alcohol solution in male sP rats, ruling out that KK-92A-induced reduction of alcohol drinking and self-administration could be due to alterations in alcohol palatability. Together, these results enhance the behavioral pharmacological profile of KK-92A and further strengthen the notion that GABAB PAMs may represent a novel class of ligands with therapeutic potential for treating alcohol use disorder.
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Affiliation(s)
- Paola Maccioni
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato (CA), Italy
| | | | - Carla Lobina
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato (CA), Italy
| | - Laura Regonini Somenzi
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato (CA), Italy
| | - Valentina Bassareo
- Department of Biomedical Sciences, University of Cagliari, Monserrato (CA), Italy
| | - Gian Luigi Gessa
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato (CA), Italy
| | | | - Patricia McDonald
- Department of Cancer Physiology, Moffitt Cancer Center, Tampa, Florida, United States
| | - Giancarlo Colombo
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato (CA), Italy.
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Dharavath RN, Pina-Leblanc C, Tang VM, Sloan ME, Nikolova YS, Pangarov P, Ruocco AC, Shield K, Voineskos D, Blumberger DM, Boileau I, Bozinoff N, Gerretsen P, Vieira E, Melamed OC, Sibille E, Quilty LC, Prevot TD. GABAergic signaling in alcohol use disorder and withdrawal: pathological involvement and therapeutic potential. Front Neural Circuits 2023; 17:1218737. [PMID: 37929054 PMCID: PMC10623140 DOI: 10.3389/fncir.2023.1218737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 09/04/2023] [Indexed: 11/07/2023] Open
Abstract
Alcohol is one of the most widely used substances. Alcohol use accounts for 5.1% of the global disease burden, contributes substantially to societal and economic costs, and leads to approximately 3 million global deaths yearly. Alcohol use disorder (AUD) includes various drinking behavior patterns that lead to short-term or long-lasting effects on health. Ethanol, the main psychoactive molecule acting in alcoholic beverages, directly impacts the GABAergic system, contributing to GABAergic dysregulations that vary depending on the intensity and duration of alcohol consumption. A small number of interventions have been developed that target the GABAergic system, but there are promising future therapeutic avenues to explore. This review provides an overview of the impact of alcohol on the GABAergic system, the current interventions available for AUD that target the GABAergic system, and the novel interventions being explored that in the future could be included among first-line therapies for the treatment of AUD.
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Affiliation(s)
| | - Celeste Pina-Leblanc
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
| | - Victor M. Tang
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Addiction Division, CAMH, Toronto, ON, Canada
- Division of Neurosciences and Clinical Translation, Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
- Institute of Mental Health Policy Research, CAMH, Toronto, ON, Canada
| | - Matthew E. Sloan
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
- Addiction Division, CAMH, Toronto, ON, Canada
- Division of Neurosciences and Clinical Translation, Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Department of Psychological Clinical Science, University of Toronto Scarborough, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
- Institute of Mental Health Policy Research, CAMH, Toronto, ON, Canada
| | - Yuliya S. Nikolova
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Peter Pangarov
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
| | - Anthony C. Ruocco
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Temerty Centre for Therapeutic Brain Intervention, CAMH, Toronto, ON, Canada
- Department of Psychology, University of Toronto Scarborough, Toronto, ON, Canada
| | - Kevin Shield
- Institute of Mental Health Policy Research, CAMH, Toronto, ON, Canada
| | - Daphne Voineskos
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Temerty Centre for Therapeutic Brain Intervention, CAMH, Toronto, ON, Canada
| | - Daniel M. Blumberger
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Temerty Centre for Therapeutic Brain Intervention, CAMH, Toronto, ON, Canada
| | - Isabelle Boileau
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Brain Health Imaging Centre, CAMH, Toronto, ON, Canada
| | - Nikki Bozinoff
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Family and Community Medicine, University of Toronto, Toronto, ON, Canada
| | - Philip Gerretsen
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
- Institute of Medical Science, University of Toronto, Toronto, ON, Canada
- Brain Health Imaging Centre, CAMH, Toronto, ON, Canada
| | - Erica Vieira
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Osnat C. Melamed
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Family and Community Medicine, University of Toronto, Toronto, ON, Canada
| | - Etienne Sibille
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Lena C. Quilty
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Thomas D. Prevot
- Campbell Family Mental Health Research Institute of CAMH, Toronto, ON, Canada
- Department of Psychiatry, University of Toronto, Toronto, ON, Canada
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Ito M, Walzer M, Blauwet MB, Spence A, Heo N, Kelsh D, Blahunka P, Erdman J, Alsharif MN, Marek GJ. A phase 1 randomized, placebo-controlled study to investigate potential interactions between ASP8062, a positive allosteric modulator of the GABA B receptor, and morphine in recreational opioid users. J Psychopharmacol 2023; 37:449-461. [PMID: 37125424 DOI: 10.1177/02698811231167852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
BACKGROUND Recent increases in opioid use and subsequent opioid use disorder are a major public health crisis in the United States. AIMS This phase 1 randomized, placebo-controlled study investigated the safety, tolerability, and pharmacokinetics (PKs) of ASP8062, a γ-aminobutyric acid B receptor-positive allosteric modulator, with and without administration of morphine in participants who used opioids recreationally. METHODS Participants were randomly assigned (2:1) to daily dosing with ASP8062 25 mg or placebo on days 1-10. On day 10, all participants received morphine as a single oral dose of 45 mg; assessments were performed on days 11-16. The primary end point was safety, evaluated as the nature, frequency, and severity of adverse events, and end-tidal CO2 levels. PK end points were a secondary outcome measure. RESULTS A total of 24 participants (aged 21-54 years) received ASP8062 (n = 16) or placebo (n = 8). There were no deaths or serious adverse events leading to treatment discontinuation during the study. Most adverse events were mild, with numerically lower absolute number of adverse events reported with ASP8062 plus morphine versus placebo plus morphine. ASP8062 plus morphine did not increase respiratory depression, potential drug abuse- or withdrawal-related adverse events. There were no significant PK interactions. CONCLUSIONS In this phase 1 study, we did not observe any unexpected safety signals or notable PK interactions with concomitant morphine administration. These data suggest a potentially low risk for an increase in drug abuse- or withdrawal-related adverse events or respiratory distress in participants exposed to ASP8062 and morphine.
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Affiliation(s)
- Mototsugu Ito
- Development Project Management, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Mark Walzer
- Clinical Pharmacology & Exploratory Development, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Mary Beth Blauwet
- Biostatistics Department, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Anna Spence
- Biostatistics Department, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Nakyo Heo
- Clinical Pharmacology & Exploratory Development, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Debra Kelsh
- Altasciences, Clinical Kansas, Inc., Overland Park, KS, USA
| | - Paul Blahunka
- Employee of Astellas, Northbrook, IL, USA, at the time of the study
| | - Jay Erdman
- Development Project Management, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Mohamad Nour Alsharif
- Development Project Management, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Gerard J Marek
- Employee of Astellas, Northbrook, IL, USA, at the time of the study
- Gilgamesh Pharmaceuticals Inc., New York, NY, USA
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Ito M, Walzer M, Beth Blauwet M, Spence A, Heo N, Kelsh D, Blahunka P, Erdman J, Nour Alsharif M, Marek GJ. A phase 1b study to investigate the potential interactions between ASP8062 and buprenorphine/naloxone in patients with opioid use disorder. J Psychopharmacol 2023; 37:144-154. [PMID: 36738100 DOI: 10.1177/02698811221149657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND There is an unmet need for therapeutics with greater efficacy and tolerability for the treatment of opioid use disorder (OUD). ASP8062 is a novel compound with positive allosteric modulator activity on the γ-aminobutyric acid type B receptor under development for use with standard-of-care treatment for patients with OUD. AIMS To investigate the safety, tolerability, interaction potential, and pharmacokinetics (PK) of ASP8062 in combination with buprenorphine/naloxone (B/N; Suboxone®). METHODS In this phase 1, randomized, double-masked, placebo-controlled study, patients with OUD began B/N (titrated to 16/4 mg/day) treatment upon enrollment (induction, Days 1-4; maintenance, Days 5-18; downward titration, Days 19-26; and discharge, Day 27). On Day 12, patients received a single dose of ASP8062 60 mg or placebo with B/N and underwent safety and PK assessments. Primary endpoints included frequency and severity of treatment-emergent adverse events (TEAEs), clinical laboratory tests, respiratory depression, and suicidal ideation. Secondary endpoints investigated the impact of ASP8062 on B/N PK. RESULTS Eighteen patients were randomized and completed the study (ASP8062, n = 12; placebo, n = 6). With this sample size typical for phase 1 drug-drug interaction studies, ASP8062 was well tolerated; most TEAEs were mild in severity, and none led to treatment withdrawal. ASP8062 did not enhance substance use-related TEAEs, respiratory depression, or suicidal ideation and did not have a clinically significant impact on the PK of B/N. CONCLUSIONS In this phase 1 study, ASP8062 was safe, well tolerated, and did not enhance respiratory suppression induced by buprenorphine. TRIAL REGISTRATION Clinicaltrials.gov identifier: NCT04447287.
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Affiliation(s)
- Mototsugu Ito
- Development Project Management, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Mark Walzer
- Clinical Pharmacology and Exploratory Development, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Mary Beth Blauwet
- Biostatistics Department, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Anna Spence
- Biostatistics Department, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Nakyo Heo
- Clinical Pharmacology and Exploratory Development, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | - Debra Kelsh
- Altasciences Clinical Kansas, Inc., Overland Park, KS, USA
| | | | - Jay Erdman
- Medical Specialties, Astellas Pharma Global Development, Inc., Northbrook, IL, USA
| | | | - Gerard J Marek
- Employee of Astellas at the time of the study.,Gilgamesh Pharmaceuticals, Inc., New York, NY, USA
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Lorrai I, Shankula C, Marquez Gaytan J, Maccioni R, Lobina C, Maccioni P, Brizzi A, Mugnaini C, Gessa GL, Sanna PP, Corelli F, Colombo G. Development of tolerance upon repeated administration with the GABA B receptor positive allosteric modulator, COR659, on alcohol drinking in rodents. THE AMERICAN JOURNAL OF DRUG AND ALCOHOL ABUSE 2022; 48:662-672. [PMID: 36095322 DOI: 10.1080/00952990.2022.2116713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 08/16/2022] [Accepted: 08/21/2022] [Indexed: 01/31/2023]
Abstract
Background: Recent work has demonstrated that acute administration of the novel positive allosteric modulator of the GABAB receptor, COR659, reduces several alcohol-related behaviors in rodents.Objective: To assess whether COR659 continues to lessen alcohol intake after repeated administration, a fundamental feature of drugs with therapeutic potential.Methods: Male C57BL/6J mice (n = 40) were exposed to daily 2-hour drinking sessions (20% (v/v) alcohol) under the 1-bottle "drinking in the dark" protocol and male Sardinian alcohol-preferring rats (n = 40) were exposed to daily 1-hour drinking sessions under the 2-bottle "alcohol (10%, v/v) vs water" choice regimen. COR659 (0, 10, 20, and 40 mg/kg in the mouse experiment; 0, 5, 10, and 20 mg/kg in the rat experiment) was administered intraperitoneally before 7 consecutive drinking sessions.Results: Alcohol intake in vehicle-treated mice and rats averaged 2.5-3.0 and 1.5-1.6 g/kg/session, respectively, indicative of high basal levels. In both experiments, treatment with COR659 resulted in an initial, dose-related suppression of alcohol intake (up to 70-80% compared to vehicle treatment; P < .0005 and P < .0001 in mouse and rat experiments, respectively). The magnitude of the reducing effect of COR659 on alcohol drinking diminished progressively, until vanishing over the subsequent 2-4 drinking sessions.Conclusion: COR659 effectively reduced alcohol intake in two different rodent models of excessive alcohol drinking. However, tolerance to the anti-alcohol effects of COR659 developed rapidly. If theoretically transposed to humans, these data would represent a possible limitation to the clinical use of COR659.
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Affiliation(s)
- Irene Lorrai
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA
| | - Chase Shankula
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA
| | - Jorge Marquez Gaytan
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA
| | - Riccardo Maccioni
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA
| | - Carla Lobina
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato, Italy
| | - Paola Maccioni
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato, Italy
| | - Antonella Brizzi
- Department of Biotechnology, Chemistry, and Pharmacy, University of Siena, Siena, Italy
| | - Claudia Mugnaini
- Department of Biotechnology, Chemistry, and Pharmacy, University of Siena, Siena, Italy
| | - Gian Luigi Gessa
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato, Italy
| | - Pietro Paolo Sanna
- Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA, USA
| | - Federico Corelli
- Department of Biotechnology, Chemistry, and Pharmacy, University of Siena, Siena, Italy
| | - Giancarlo Colombo
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, Monserrato, Italy
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Maccioni P, Kaczanowska K, McDonald P, Colombo G. Development of Partial Tolerance to the Suppressing Effect of the Positive Allosteric Modulator of the GABAB Receptor, KK-92A, on Alcohol Self-Administration in Rats. Alcohol Alcohol 2022; 57:706-711. [PMID: 35589119 DOI: 10.1093/alcalc/agac026] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 03/17/2022] [Accepted: 04/27/2022] [Indexed: 11/12/2022] Open
Abstract
AIMS A recent study reported how acute treatment with KK-92A, a newly synthesized positive allosteric modulator (PAMs) of the GABAB receptor (GABAB PAMs), suppressed a series of alcohol-related behaviors, including operant oral alcohol self-administration, in selectively bred Sardinian alcohol-preferring (sP) rats. These findings lead to the addition of KK-92A to the long list of GABAB PAMs capable of reducing, after acute treatment, alcohol self-administration in rats. As a further step toward a more complete characterization of the anti-addictive properties of KK-92A, the present study was designed to assess the effect of repeated treatment with the compound on alcohol self-administration. METHODS sP rats were trained to lever-respond for oral alcohol (15%, v/v) under the fixed ratio 5 (FR5) schedule of reinforcement. Once lever-responding behavior had stabilized, KK-92A (0, 5, 10 and 20 mg/kg, i.p.) was administered 30 min prior to 10 consecutive daily self-administration sessions (likewise occurring under the FR5 schedule). RESULTS The first injection of KK-92A produced a dose-related suppression in number of lever-responses for alcohol and amount of self-administered alcohol. Magnitude of the suppressing effect of KK-92A decreased over the following two self-administration sessions and then tended to stabilize on continuation of treatment. Statistical significance at post hoc analysis was maintained only by the highest dose tested (20 mg/kg). CONCLUSIONS These data suggest the development of partial tolerance to the reducing effect of repeatedly administered KK-92A on alcohol self-administration. The agonistic component of the ago-allosteric profile of KK-92A is discussed as the likely key element underlying the observed tolerance.
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Affiliation(s)
- Paola Maccioni
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, I-09042 Monserrato, Italy
| | | | - Patricia McDonald
- Department of Cancer Physiology, Moffitt Cancer Center, Tampa, FL 33612, USA
| | - Giancarlo Colombo
- Neuroscience Institute, Section of Cagliari, National Research Council of Italy, I-09042 Monserrato, Italy
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