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Seaman RW, Lamon K, Whitton N, Latimer B, Sulima A, Rice KC, Murnane KS, Collins GT. Impacts of Self-Administered 3,4-Methylenedioxypyrovalerone (MDPV) Alone, and in Combination with Caffeine, on Recognition Memory and Striatal Monoamine Neurochemistry in Male Sprague Dawley Rats: Comparisons with Methamphetamine and Cocaine. Brain Sci 2024; 14:258. [PMID: 38539646 PMCID: PMC10969043 DOI: 10.3390/brainsci14030258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 02/29/2024] [Accepted: 02/29/2024] [Indexed: 04/04/2024] Open
Abstract
Recent data suggest that 3,4-methylenedioxypyrovalerone (MDPV) has neurotoxic effects; however, the cognitive and neurochemical consequences of MDPV self-administration remain largely unexplored. Furthermore, despite the fact that drug preparations that contain MDPV often also contain caffeine, little is known regarding the toxic effects produced by the co-use of these two stimulants. The current study investigated the degree to which self-administered MDPV or a mixture of MDPV+caffeine can produce deficits in recognition memory and alter neurochemistry relative to prototypical stimulants. Male Sprague Dawley rats were provided 90 min or 12 h access to MDPV, MDPV+caffeine, methamphetamine, cocaine, or saline for 6 weeks. Novel object recognition (NOR) memory was evaluated prior to any drug self-administration history and 3 weeks after the final self-administration session. Rats that had 12 h access to methamphetamine and those that had 90 min or 12 h access to MDPV+caffeine exhibited significant deficits in NOR, whereas no significant deficits were observed in rats that self-administered cocaine or MDPV. Striatal monoamine levels were not systematically affected. These data demonstrate synergism between MDPV and caffeine with regard to producing recognition memory deficits, highlighting the importance of recapitulating the manner in which drugs are used (e.g., in mixtures containing multiple stimulants, binge-like patterns of intake).
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Affiliation(s)
- Robert W. Seaman
- Department of Pharmacology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Kariann Lamon
- Department of Pharmacology, Toxicology and Neuroscience, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
- Louisiana Addiction Research Center, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
- Department of Psychiatry and Behavioral Medicine, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
| | - Nicholas Whitton
- Department of Pharmacology, Toxicology and Neuroscience, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
- Louisiana Addiction Research Center, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
- Department of Psychiatry and Behavioral Medicine, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
| | - Brian Latimer
- Department of Pharmacology, Toxicology and Neuroscience, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
- Louisiana Addiction Research Center, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
- Department of Psychiatry and Behavioral Medicine, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
| | - Agnieszka Sulima
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kenner C. Rice
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kevin S. Murnane
- Department of Pharmacology, Toxicology and Neuroscience, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
- Louisiana Addiction Research Center, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
- Department of Psychiatry and Behavioral Medicine, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA 71103, USA
| | - Gregory T. Collins
- Department of Pharmacology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
- South Texas Veterans Health Care System, San Antonio, TX 78229, USA
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Seaman RW, Galindo DG, Stinson BT, Sulima A, Rice KC, Javors MA, Ginsburg BC, Collins GT. Cardiovascular and Locomotor Effects of Binary Mixtures of Common "Bath Salts" Constituents: Studies with Methylone, MDPV, and Caffeine in Rats. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.31.578069. [PMID: 38352520 PMCID: PMC10862873 DOI: 10.1101/2024.01.31.578069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
Background and Purpose The use of "Bath Salts" drug preparations has been associated with high rates of toxicity and death. Preparations often contain mixtures of drugs including multiple synthetic cathinones or synthetic cathinones and caffeine; however, little is known about whether interactions among "Bath Salts" constituents contribute to the adverse effects often reported in users. Experimental Approach This study used adult male Sprague-Dawley rats to characterize the cardiovascular effects, locomotor effects, and pharmacokinetics of methylone, MDPV, and caffeine, administered alone and as binary mixtures. Dose-addition analyses were used to determine the effect levels predicted for a strictly additive interaction for each dose pair. Key Results Methylone, MDPV, and caffeine increased heart rate and locomotion, with methylone producing the largest increase in heart rate, MDPV producing the largest increase in locomotor activity, and caffeine being the least effective in stimulating heart rate and locomotor activity. MDPV and caffeine increased mean arterial pressure, with caffeine being more effective than MDPV. The nature of the interactions between methylone and MDPV tended toward sub-additivity for all endpoints, whereas interactions between MDPV or methylone and caffeine tended to be additive or sub-additive for cardiovascular endpoints, and additive or supra-additive for increases in locomotion. No pharmacokinetic interactions were observed between individual constituents, but methylone displayed non-linear pharmacokinetics at the largest dose evaluated. Conclusion and Implications These findings demonstrate that the composition of "Bath Salts" preparations can impact both cardiovascular and locomotor effects and suggest that such interactions among constituent drugs could contribute to the "Bath Salts" toxidrome reported by human users.
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Affiliation(s)
- Robert W Seaman
- Department of Pharmacology, The University of Texas Health Science Center at San Antonio
| | - David G Galindo
- Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at San Antonio
| | - Benjamin T Stinson
- Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at San Antonio
| | - Agnieszka Sulima
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, NIDA and NIAAA, Bethesda, MD, USA
| | - Kenner C Rice
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, NIDA and NIAAA, Bethesda, MD, USA
| | - Martin A Javors
- Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at San Antonio
| | - Brett C Ginsburg
- Department of Psychiatry and Behavioral Sciences, The University of Texas Health Science Center at San Antonio
| | - Gregory T Collins
- Department of Pharmacology, The University of Texas Health Science Center at San Antonio
- South Texas Veterans Health Care System, San Antonio, TX, USA
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3
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Seaman RW, Lamon K, Whitton N, Latimer B, Sulima A, Rice KC, Murnane KS, Collins GT. Impacts of Self-Administered 3,4-Methylenedioxypyrovalerone (MDPV) Alone, and in Combination with Caffeine, on Recognition Memory and Striatal Monoamine Neurochemistry in Male Sprague-Dawley Rats: Comparisons with Methamphetamine and Cocaine. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.31.578247. [PMID: 38352595 PMCID: PMC10862826 DOI: 10.1101/2024.01.31.578247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
Recent data suggest that 3,4-methylenedioxypyrovalerone (MDPV) has neurotoxic effects; however, the cognitive and neurochemical consequences of MDPV self-administration remain largely unexplored. Furthermore, despite the fact that drug preparations that contain MDPV often also contain caffeine, little is known regarding the toxic effects produced by the co-use of these two stimulants. The current study investigated the degree to which self-administered MDPV, or a mixture of MDPV+caffeine can produce deficits in recognition memory and alter neurochemistry relative to prototypical stimulants. Male Sprague-Dawley rats were provided 90-min or 12-h access to MDPV, MDPV+caffeine, methamphetamine, cocaine, or saline for 6 weeks. Novel object recognition (NOR) memory was evaluated prior to any drug self-administration history and 3 weeks after the final self-administration session. Rats that had 12-h access to methamphetamine and those that had 90-min or 12-h access to MDPV+caffeine exhibited significant deficits in NOR, whereas no significant deficits were observed in rats that self-administered cocaine or MDPV. Striatal mono-amine levels were not systematically affected. These data demonstrate synergism between MDPV and caffeine with regard to producing recognition memory deficits and lethality, highlighting the importance of recapitulating the manner in which drugs are used (e.g., in mixtures containing multiple stimulants, binge-like patterns of intake).
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Affiliation(s)
- Robert W Seaman
- Department of Pharmacology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
| | - Kariann Lamon
- Department of Pharmacology, Toxicology and Neuroscience, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA, United States
- Louisiana Addiction Research Center, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA, United States
- Department of Psychiatry and Behavioral Medicine, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA, United States
| | - Nicholas Whitton
- Department of Pharmacology, Toxicology and Neuroscience, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA, United States
- Louisiana Addiction Research Center, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA, United States
- Department of Psychiatry and Behavioral Medicine, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA, United States
| | - Brian Latimer
- Department of Pharmacology, Toxicology and Neuroscience, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA, United States
- Louisiana Addiction Research Center, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA, United States
- Department of Psychiatry and Behavioral Medicine, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA, United States
| | - Agnieszka Sulima
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, United States
| | - Kenner C Rice
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, Intramural Research Program, National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health, Bethesda, Maryland, United States
| | - Kevin S Murnane
- Department of Pharmacology, Toxicology and Neuroscience, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA, United States
- Louisiana Addiction Research Center, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA, United States
- Department of Psychiatry and Behavioral Medicine, Louisiana State University Health Sciences Center at Shreveport, Shreveport, LA, United States
| | - Gregory T Collins
- Department of Pharmacology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, United States
- South Texas Veterans Health Care System, San Antonio, TX, United States
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Dragan AM, Feier BG, Tertiș M, Bodoki E, Truta F, Ștefan MG, Kiss B, Van Durme F, De Wael K, Oprean R, Cristea C. Forensic Analysis of Synthetic Cathinones on Nanomaterials-Based Platforms: Chemometric-Assisted Voltametric and UPLC-MS/MS Investigation. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:2393. [PMID: 37686901 PMCID: PMC10489959 DOI: 10.3390/nano13172393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Revised: 08/15/2023] [Accepted: 08/18/2023] [Indexed: 09/10/2023]
Abstract
Synthetic cathinones (SCs) are a group of new psychoactive substances often referred to as "legal highs" or "bath salts", being characterized by a dynamic change, new compounds continuously emerging on the market. This creates a lack of fast screening tests, making SCs a constant concern for law enforcement agencies. Herein, we present a fast and simple method for the detection of four SCs (alpha-pyrrolidinovalerophenone, N-ethylhexedrone, 4-chloroethcathinone, and 3-chloromethcathinone) based on their electrochemical profiles in a decentralized manner. In this regard, the voltametric characterization of the SCs was performed by cyclic and square wave voltammetry. The elucidation of the SCs redox pathways was successfully achieved using liquid chromatography coupled to (tandem) mass spectrometry. For the rational identification of the ideal experimental conditions, chemometric data processing was employed, considering two critical qualitative and quantitative variables: the type of the electrochemical platform and the pH of the electrolyte. The analytical figures of merit were determined on standard working solutions using the optimized method, which exhibited wide linear ranges and LODs suitable for confiscated sample screening. Finally, the performance of the method was evaluated on real confiscated samples, the resulting validation parameters being similar to those obtained with another portable device (i.e., Raman spectrometer).
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Affiliation(s)
- Ana-Maria Dragan
- Department of Analytical Chemistry, Faculty of Pharmacy, 'Iuliu Hațieganu' University of Medicine and Pharmacy, Pasteur 6, 400349 Cluj-Napoca, Romania
- A-Sense Lab, University of Antwerp, Groenenborgerlaan 171, 2010 Antwerp, Belgium
| | - Bogdan George Feier
- Department of Analytical Chemistry, Faculty of Pharmacy, 'Iuliu Hațieganu' University of Medicine and Pharmacy, Pasteur 6, 400349 Cluj-Napoca, Romania
| | - Mihaela Tertiș
- Department of Analytical Chemistry, Faculty of Pharmacy, 'Iuliu Hațieganu' University of Medicine and Pharmacy, Pasteur 6, 400349 Cluj-Napoca, Romania
| | - Ede Bodoki
- Department of Analytical Chemistry, Faculty of Pharmacy, 'Iuliu Hațieganu' University of Medicine and Pharmacy, Pasteur 6, 400349 Cluj-Napoca, Romania
| | - Florina Truta
- Department of Analytical Chemistry, Faculty of Pharmacy, 'Iuliu Hațieganu' University of Medicine and Pharmacy, Pasteur 6, 400349 Cluj-Napoca, Romania
| | - Maria-Georgia Ștefan
- Department of Toxicology, Faculty of Pharmacy, 'Iuliu Hațieganu' University of Medicine and Pharmacy, Pasteur 6, 400349 Cluj-Napoca, Romania
| | - Béla Kiss
- Department of Toxicology, Faculty of Pharmacy, 'Iuliu Hațieganu' University of Medicine and Pharmacy, Pasteur 6, 400349 Cluj-Napoca, Romania
| | - Filip Van Durme
- Drugs and Toxicology Department, National Institute for Criminalistics and Criminology (NICC), Vilvoordsesteenweg 100, 1120 Brussels, Belgium
| | - Karolien De Wael
- A-Sense Lab, University of Antwerp, Groenenborgerlaan 171, 2010 Antwerp, Belgium
- NANOlab Center of Excellence, University of Antwerp, Groenenborgerlaan 171, 2010 Antwerp, Belgium
| | - Radu Oprean
- Department of Analytical Chemistry, Faculty of Pharmacy, 'Iuliu Hațieganu' University of Medicine and Pharmacy, Pasteur 6, 400349 Cluj-Napoca, Romania
| | - Cecilia Cristea
- Department of Analytical Chemistry, Faculty of Pharmacy, 'Iuliu Hațieganu' University of Medicine and Pharmacy, Pasteur 6, 400349 Cluj-Napoca, Romania
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Relative reinforcing effects of dibutylone, ethylone, and N-ethylpentylone: self-administration and behavioral economics analysis in rats. Psychopharmacology (Berl) 2022; 239:2875-2884. [PMID: 35716192 DOI: 10.1007/s00213-022-06173-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 06/06/2022] [Indexed: 01/23/2023]
Abstract
RATIONALE Following the emergence of methylone as one of the most popular synthetic cathinones, this group of novel psychoactive substance with names ending in "-lone," such as dibutylone, ethylone, and N-ethylpentylone, appeared on the recreational drug market. The pharmacological mechanisms of dibutylone, ethylone, and N-ethylpentylone are well understood; however, to date, the reinforcing effects of dibutylone, ethylone, and N-ethylpentylone are still unclear. OBJECTIVES This study aimed to examine the self-administration of dibutylone, ethylone, and N-ethylpentylone relative to methamphetamine (METH) and to quantify their relative reinforcing effectiveness using behavioral economic analysis. METHODS Male Sprague-Dawley rats were trained to self-administer METH (0.05 mg/kg) under a fixed-ratio 1 (FR1) schedule. Following the training, dose substitution was used to generate full dose-response curves for METH and the three synthetic cathinones. According to the first doses on the descending limb of the dose-response curves, rats were trained to self-administer METH (0.05 mg/kg), dibutylone (0.1 mg·kg-1·infusion-1), ethylone (0.4 mg·kg-1·infusion-1), or N-ethylpentylone (0.1 mg·kg-1·infusion-1) under an FR1 schedule, and a behavioral economic evaluation of their reinforcing effectiveness was then performed. RESULTS Dibutylone, ethylone, and N-ethylpentylone functioned as reinforcers, and the inverted U-shaped dose-response curves were obtained. The rank order of reinforcing potency in this procedure was METH > N-ethylpentylone ≈ dibutylone > ethylone. In the economic analysis, the comparisons of the essential value (EV) transformed from demand elasticity (α) indicated that the rank order of efficacy as reinforcers was METH (EV = 7.93) ≈ dibutylone (EV = 7.81) > N-ethylpentylone (EV = 5.21) ≈ ethylone (EV = 4.19). CONCLUSIONS These findings demonstrated that dibutylone, ethylone, and N-ethylpentylone function as reinforcers and have addictive potential, suggesting that the modification of α-alkyl and N-alkyl side chains may affect their reinforcing efficacy.
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Contribution of Illicit Drug Use to Pharmaceutical Load in the Environment: A Focus on Sub-Saharan Africa. JOURNAL OF ENVIRONMENTAL AND PUBLIC HEALTH 2022; 2022:9056476. [PMID: 35719855 PMCID: PMC9200571 DOI: 10.1155/2022/9056476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 10/25/2021] [Accepted: 05/10/2022] [Indexed: 11/17/2022]
Abstract
Illicit drug abuse and addiction are universal issues requiring international cooperation and interdisciplinary and multisectoral solutions. These addictive substances are utilized for recreational purposes worldwide, including in sub-Saharan Africa. On the other hand, conventional wastewater treatment facilities such as waste stabilization ponds lack the design to remove the most recent classes of pollutants such as illicit drug abuse. As a result, effluents from these treatment schemes contaminate the entire ecosystem. Public health officials are concerned about detecting these pollutants at alarming levels in some countries, with potential undesirable effects on aquatic species and increased health hazards through exposure to contaminated waters or recycling treated or untreated effluents in agriculture. Contaminants including illicit substances enter the environment by human excreta following illegal intake, spills, or through direct dumping, such as from clandestine laboratories, when their manufacturer does not follow accepted production processes. These substances, like other pharmaceuticals, have biological activity and range from pseudopersistent to highly persistent compounds; hence, they persist in the environment while causing harm to the ecosystem. The presence of powerful pharmacological agents such as cocaine, morphine, and amphetamine in water as complex combinations can impair aquatic organisms and human health. These compounds can harm human beings and ecosystem health apart from their low environmental levels. Therefore, this article examines the presence and levels of illicit substances in ecological compartments such as wastewater, surface and ground waters in sub-Saharan Africa, and their latent impact on the ecosystem. The information on the occurrences of illicit drugs and their metabolic products in the sub-Saharan Africa environment and their contribution to pharmaceutical load is missing. In this case, it is important to research further the presence, levels, distribution, and environmental risks of exposure to human beings and the entire ecosystem.
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Doyle MR, Gannon BM, Mesmin MP, Collins GT. Application of dose-addition analyses to characterize the abuse-related effects of drug mixtures. J Exp Anal Behav 2022; 117:442-456. [PMID: 35142382 PMCID: PMC9327442 DOI: 10.1002/jeab.741] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 01/07/2022] [Accepted: 01/11/2022] [Indexed: 11/12/2022]
Abstract
Polysubstance use makes up a majority of drug use, yet relatively few studies investigate the abuse-related effects of drug mixtures. Dose-addition analyses provide a rigorous and quantitative method to determine the nature of the interaction (i.e., supraadditive, additive, or subadditive) between two or more drugs. As briefly reviewed here, studies in rhesus monkeys have applied dose-addition analyses to group level data to characterize the nature of the interaction between the reinforcing effects of stimulants and opioids (e.g., mixtures of cocaine + heroin). Building upon these foundational studies, more recent work has applied dose-addition analyses to better understand the nature of the interaction between caffeine and illicit stimulants such as MDPV and methamphetamine in rats. In addition to utilizing a variety of operant procedures, including drug discrimination, drug self-administration, and drug-primed reinstatement, these studies have incorporated potency and effectiveness ratios as a method for both statistical analysis and visualization of departures from additivity at both the group and individual subject level. As such, dose-addition analyses represent a powerful and underutilized approach to quantify the nature of drug-drug interactions that can be applied to a variety of abuse-related endpoints in order to better understand the behavioral pharmacology of polysubstance use.
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Affiliation(s)
- Michelle R Doyle
- Department of Pharmacology, University of Texas Health Science Center at San Antonio.,South Texas Veterans Health Care System, San Antonio
| | - Brenda M Gannon
- Department of Pharmacology, University of Texas Health Science Center at San Antonio
| | - Melson P Mesmin
- Department of Pharmacology, University of Texas Health Science Center at San Antonio
| | - Gregory T Collins
- Department of Pharmacology, University of Texas Health Science Center at San Antonio.,South Texas Veterans Health Care System, San Antonio
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8
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Flynn SM, France CP. Characterization of the discriminative stimulus effects of binary mixtures of mu opioid receptor agonists in rats discriminating fentanyl. J Pharmacol Exp Ther 2021; 380:171-179. [PMID: 34903563 DOI: 10.1124/jpet.121.000912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 12/09/2021] [Indexed: 11/22/2022] Open
Abstract
Drug overdose deaths involving synthetic opioids, primarily fentanyl, have risen dramatically over the past decade and are currently the driving force of the opioid epidemic in the United States. Fentanyl analogs with greater potency than fentanyl (e.g., carfentanil) pose serious risk to public health. While fentanyl analogs are primarily encountered by humans as constituents of a mixture of drugs, research has primarily evaluated the effects of these drugs alone. The present study characterized interactions between mu opioid receptor agonists in seven male Sprague-Dawley rats trained to discriminate 10 µg/kg fentanyl from saline while responding under a fixed-ratio 10 schedule of food presentation. Dose-effect curves were determined for each drug alone and in binary mixtures (fentanyl:heroin, fentanyl:carfentanil, and heroin:carfentanil) at fixed-dose ratios of 3:1, 1:1, and 1:3 relative to the ED50 for each drug when given alone. Dose addition analyses were used to determine the nature of the drug-drug interaction for each mixture. Additive interactions were observed for all binary mixtures at each fixed dose ratio, except the 1:3 fentanyl:carfentanil mixture which exhibited supra-additive effects at the 80% effect level. These results suggest a lack of a significant interaction between the discriminative stimulus effects of these mu opioid receptor agonists at the doses tested in this study. Future studies expanding these findings to the respiratory depressant effects of these drugs are of significant importance to rule out possible interactions directly relevant to opioid overdose that occur at doses much larger than those tested in this study. Significance Statement In the United States, drug overdose deaths involving synthetic opioids, primarily fentanyls including superpotent fentanyl analogs (e.g., carfentanil), have increased 12-fold over the past decade. While previous studies have evaluated the effects of carfentanil alone, fentanyl analogs are encountered by humans as a mixture with other drugs; this study determined the effects of mixtures of carfentanil and other opioids (fentanyl and heroin) to characterize interactions between these drugs that might contribute to their apparent increased lethality in humans.
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Affiliation(s)
- Shawn M Flynn
- University of Texas Health Science Center, United States
| | - Charles P France
- Department of Pharmacology, University of Texas Health Science Center, United States
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9
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Centazzo N, Chojnacki MR, Elmore JS, Rodriguez R, Acosta T, Suzuki M, Rice KC, Baumann MH, Concheiro M. Brain Concentrations of Methylone and Its Metabolites after Systemic Methylone Administration: Relationship to Pharmacodynamic Effects. J Pharmacol Exp Ther 2021; 377:398-406. [PMID: 33785525 PMCID: PMC11058058 DOI: 10.1124/jpet.121.000531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 03/24/2021] [Indexed: 01/01/2023] Open
Abstract
3,4-Methylenedioxy-N-methylcathinone (methylone) is a new psychoactive substance with stimulant properties and potential for abuse. Despite its popularity, limited studies have examined relationships between brain concentrations of methylone, its metabolites, and pharmacodynamic effects. The goal of the present study was 2-fold: 1) to determine pharmacokinetics of methylone and its major metabolites-4-hydroxy-3-methoxy-N-methylcathinone (HMMC), 3,4-dihydroxy-N-methylcathinone (HHMC), and 3,4-methylenedioxycathinone (MDC)-in rat brain and plasma and 2) to relate brain pharmacokinetic parameters to pharmacodynamic effects including locomotor behavior and postmortem neurochemistry. Male Sprague-Dawley rats received subcutaneous methylone (6, 12, or 24 mg/kg) or saline vehicle (n = 16/dose), and subgroups were decapitated after 40 or 120 minutes. Plasma and prefrontal cortex were analyzed for concentrations of methylone and its metabolites by liquid chromatography-tandem mass spectrometry. Frontal cortex and dorsal striatum were analyzed for dopamine, 5-HT, and their metabolites by high-performance liquid chromatography-electrochemical detection. Brain and plasma concentrations of methylone and its metabolites rose with increasing methylone dose, but brain methylone and MDC concentrations were greater than dose-proportional. Brain-to-plasma ratios for methylone and MDC were ≥ 3 (range 3-12), whereas those for HHMC and HMMC were ≤ 0.2 (range 0.01-0.2). Locomotor activity score was positively correlated with brain methylone and MDC, whereas cortical 5-HT was negatively correlated with these analytes at 120 minutes. Our findings show that brain concentrations of methylone and MDC display nonlinear accumulation. Behavioral and neurochemical effects of systemically administered methylone are related to brain concentrations of methylone and MDC but not its hydroxylated metabolites, which do not effectively penetrate into the brain. SIGNIFICANCE STATEMENT: Behavioral and neurochemical effects of methylone are related to brain concentrations of methylone and its metabolite MDC but not its hydroxylated metabolites, 4-hydroxy-3-methoxy-N-methylcathinone and 3,4-dihydroxy-N-methylcathinone, which do not effectively penetrate into the brain. Methylone and MDC display nonlinear accumulation in the brain, which could cause untoward effects on serotonin neurons in vulnerable brain regions, including the frontal cortex.
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Affiliation(s)
- Nicole Centazzo
- Department of Sciences, John Jay College of Criminal Justice, City University of New York, New York, New York (N.C., R.R., T.A., M.C.); Designer Drug Research Unit, Intramural Research Program (IRP), National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH), Baltimore, Maryland (M.R.C., J.S.E., M.H.B.); and Drug Design and Synthesis Section, IRP, NIDA, NIH, Rockville, Maryland (M.S., K.C.R.)
| | - Michael R Chojnacki
- Department of Sciences, John Jay College of Criminal Justice, City University of New York, New York, New York (N.C., R.R., T.A., M.C.); Designer Drug Research Unit, Intramural Research Program (IRP), National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH), Baltimore, Maryland (M.R.C., J.S.E., M.H.B.); and Drug Design and Synthesis Section, IRP, NIDA, NIH, Rockville, Maryland (M.S., K.C.R.)
| | - Joshua S Elmore
- Department of Sciences, John Jay College of Criminal Justice, City University of New York, New York, New York (N.C., R.R., T.A., M.C.); Designer Drug Research Unit, Intramural Research Program (IRP), National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH), Baltimore, Maryland (M.R.C., J.S.E., M.H.B.); and Drug Design and Synthesis Section, IRP, NIDA, NIH, Rockville, Maryland (M.S., K.C.R.)
| | - Raider Rodriguez
- Department of Sciences, John Jay College of Criminal Justice, City University of New York, New York, New York (N.C., R.R., T.A., M.C.); Designer Drug Research Unit, Intramural Research Program (IRP), National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH), Baltimore, Maryland (M.R.C., J.S.E., M.H.B.); and Drug Design and Synthesis Section, IRP, NIDA, NIH, Rockville, Maryland (M.S., K.C.R.)
| | - Teeshavi Acosta
- Department of Sciences, John Jay College of Criminal Justice, City University of New York, New York, New York (N.C., R.R., T.A., M.C.); Designer Drug Research Unit, Intramural Research Program (IRP), National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH), Baltimore, Maryland (M.R.C., J.S.E., M.H.B.); and Drug Design and Synthesis Section, IRP, NIDA, NIH, Rockville, Maryland (M.S., K.C.R.)
| | - Masaki Suzuki
- Department of Sciences, John Jay College of Criminal Justice, City University of New York, New York, New York (N.C., R.R., T.A., M.C.); Designer Drug Research Unit, Intramural Research Program (IRP), National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH), Baltimore, Maryland (M.R.C., J.S.E., M.H.B.); and Drug Design and Synthesis Section, IRP, NIDA, NIH, Rockville, Maryland (M.S., K.C.R.)
| | - Kenner C Rice
- Department of Sciences, John Jay College of Criminal Justice, City University of New York, New York, New York (N.C., R.R., T.A., M.C.); Designer Drug Research Unit, Intramural Research Program (IRP), National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH), Baltimore, Maryland (M.R.C., J.S.E., M.H.B.); and Drug Design and Synthesis Section, IRP, NIDA, NIH, Rockville, Maryland (M.S., K.C.R.)
| | - Michael H Baumann
- Department of Sciences, John Jay College of Criminal Justice, City University of New York, New York, New York (N.C., R.R., T.A., M.C.); Designer Drug Research Unit, Intramural Research Program (IRP), National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH), Baltimore, Maryland (M.R.C., J.S.E., M.H.B.); and Drug Design and Synthesis Section, IRP, NIDA, NIH, Rockville, Maryland (M.S., K.C.R.)
| | - Marta Concheiro
- Department of Sciences, John Jay College of Criminal Justice, City University of New York, New York, New York (N.C., R.R., T.A., M.C.); Designer Drug Research Unit, Intramural Research Program (IRP), National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH), Baltimore, Maryland (M.R.C., J.S.E., M.H.B.); and Drug Design and Synthesis Section, IRP, NIDA, NIH, Rockville, Maryland (M.S., K.C.R.)
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10
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Seaman RW, Collins GT. Impact of Morphine Dependence and Withdrawal on the Reinforcing Effectiveness of Fentanyl, Cocaine, and Methamphetamine in Rats. Front Pharmacol 2021; 12:691700. [PMID: 34093214 PMCID: PMC8175987 DOI: 10.3389/fphar.2021.691700] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 05/10/2021] [Indexed: 11/23/2022] Open
Abstract
Recent estimates suggest increased popularity of the concurrent use of opioids and stimulants, with over 50% of treatment-seeking opioid users reporting regular stimulant use. The goal of the current study was to determine how opioid dependence and withdrawal affect the reinforcing effects of fentanyl, cocaine, and methamphetamine. Male Sprague-Dawley rats were allowed to self-administer fentanyl under a progressive ratio (PR) schedule of reinforcement. Baseline evaluations of reinforcing effectiveness of fentanyl, cocaine, and methamphetamine were determined. Opioid dependence was then established by administering escalating doses of morphine (10–40 mg/kg) twice-daily for four days and subsequently maintained by once-daily injections of 40 mg/kg morphine. To evaluate the impact of opioid dependence and withdrawal on the self-administration of fentanyl, cocaine, and methamphetamine, sessions occurred either 12 or 20 h after the morphine, respectively. During opioid withdrawal, the fentanyl dose-response curve was shifted rightward with an increase in maximal effectiveness, whereas it was shifted rightward with a reduction in maximal effectiveness when evaluated in rats currently dependent on opioids, relative to baseline. The reinforcing effects of cocaine and methamphetamine were unchanged by either condition. The current studies provide direct evidence that the reinforcing effects of fentanyl are increased in opioid-withdrawn rats and reduced in opioid-dependent rats, relative to rats that are not physically dependent on opioids. These findings suggest that motivations to use opioids are dependent on the state of the individual whereas stimulants retain their reinforcing effects regardless of whether the individual is in an opioid-dependent or withdrawn state.
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Affiliation(s)
- Robert W Seaman
- Department of Pharmacology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, United States.,South Texas Veterans Health Care System, San Antonio, TX, United States
| | - Gregory T Collins
- Department of Pharmacology, The University of Texas Health Science Center at San Antonio, San Antonio, TX, United States.,South Texas Veterans Health Care System, San Antonio, TX, United States
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11
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Li Y, Luo Z, Li G, Belwal T, Li L, Xu Y, Su B, Lin X. Interference-free Detection of Caffeine in Complex Matrices Using a Nanochannel Electrode Modified with Binary Hydrophilic-Hydrophobic PDMS. ACS Sens 2021; 6:1604-1612. [PMID: 33752324 DOI: 10.1021/acssensors.1c00004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In the present study, a novel electrochemical sensor for the direct detection of caffeine in the crude sample has been prepared by plasma-triggered polydimethylsiloxane (PDMS) deposition on the indium tin oxide electrodes supported with silica nanochannels. The deposited PDMS contains both the original hydrophobic and oxidized hydrophilic PDMS oligomers. Nanochannels modified with these two kinds of PDMS with opposite wettability only allow the passage of small amphiphilic molecules such as caffeine, while other molecules including hydrophilic, hydrophobic, and large ones were all rejected. With the excellent shielding properties, the modified nanochannel electrode exhibits excellent anti-interference and antifouling capability, which could be directly used for the detection of caffeine in real crude food such as tea, milk, coffee, and coke without sample pretreatments. Moreover, the modified electrode has good repeatability and stability. In contrast, severe interference was observed when conventional electrodes were used directly in these unprocessed samples. The linear ranges of caffeine were determined to be between 50 nmol/L and 700 μmol/L, with a limit of detection of 20 nmol/L. The developed sensor provides a very simple, rapid, and cost-effective way for the interference-free and fouling-free analysis of specific amphiphilic compounds and can be extended to a wide range of applications.
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Affiliation(s)
- Yintao Li
- College of Biosystems Engineering and Food Science, Key Laboratory of Agro-Products Postharvest Handling of Ministry of Agriculture and Rural Affairs, Zhejiang Key Laboratory for Agri-Food Processing, Zhejiang University, Hangzhou 310058, China
| | - Zisheng Luo
- College of Biosystems Engineering and Food Science, Key Laboratory of Agro-Products Postharvest Handling of Ministry of Agriculture and Rural Affairs, Zhejiang Key Laboratory for Agri-Food Processing, Zhejiang University, Hangzhou 310058, China
- China National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang R&D Center for Food Technology and Equipment, Hangzhou 310058, China
- Ningbo Research Institute, Zhejiang University, Ningbo 315100, China
| | - Gangfeng Li
- College of Biosystems Engineering and Food Science, Key Laboratory of Agro-Products Postharvest Handling of Ministry of Agriculture and Rural Affairs, Zhejiang Key Laboratory for Agri-Food Processing, Zhejiang University, Hangzhou 310058, China
| | - Tarun Belwal
- College of Biosystems Engineering and Food Science, Key Laboratory of Agro-Products Postharvest Handling of Ministry of Agriculture and Rural Affairs, Zhejiang Key Laboratory for Agri-Food Processing, Zhejiang University, Hangzhou 310058, China
| | - Li Li
- College of Biosystems Engineering and Food Science, Key Laboratory of Agro-Products Postharvest Handling of Ministry of Agriculture and Rural Affairs, Zhejiang Key Laboratory for Agri-Food Processing, Zhejiang University, Hangzhou 310058, China
- China National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang R&D Center for Food Technology and Equipment, Hangzhou 310058, China
| | - Yanqun Xu
- College of Biosystems Engineering and Food Science, Key Laboratory of Agro-Products Postharvest Handling of Ministry of Agriculture and Rural Affairs, Zhejiang Key Laboratory for Agri-Food Processing, Zhejiang University, Hangzhou 310058, China
- Ningbo Research Institute, Zhejiang University, Ningbo 315100, China
| | - Bin Su
- Institute of Analytical Chemistry, Department of Chemistry, Zhejiang University, Hangzhou 310058, China
| | - Xingyu Lin
- College of Biosystems Engineering and Food Science, Key Laboratory of Agro-Products Postharvest Handling of Ministry of Agriculture and Rural Affairs, Zhejiang Key Laboratory for Agri-Food Processing, Zhejiang University, Hangzhou 310058, China
- China National-Local Joint Engineering Laboratory of Intelligent Food Technology and Equipment, Zhejiang R&D Center for Food Technology and Equipment, Hangzhou 310058, China
- Ningbo Research Institute, Zhejiang University, Ningbo 315100, China
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12
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MDPV "high-responder" rats also self-administer more oxycodone than their "low-responder" counterparts under a fixed ratio schedule of reinforcement. Psychopharmacology (Berl) 2021; 238:1183-1192. [PMID: 33484299 DOI: 10.1007/s00213-021-05764-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 01/12/2021] [Indexed: 02/06/2023]
Abstract
RATIONALE Oxycodone is one of the most commonly prescribed and most frequently abused opioid analgesics, yet little is known regarding individual vulnerabilities to oxycodone abuse. The synthetic cathinone 3,4-methylenedioxypyrovalerone (MDPV) has been shown to produce a "high-responder" phenotype characterized by increased drug intake and responding during periods of signaled drug unavailability (e.g., during post-infusion timeouts) in ~ 40% of male Sprague-Dawley rats. This phenotype also transfers to other psychostimulants (e.g., cocaine and methamphetamine), but it is unknown whether this phenotype transfers to other (non-stimulant) drugs of abuse. OBJECTIVES The present study aimed to (1) reestablish the "high-responder" phenotype in male Sprague-Dawley rats (n = 11) that acquired self-administration of MDPV (0.032 mg/kg/inf) on a fixed ratio 1 (FR1) schedule of reinforcement and (2) compare full dose-response curves for MDPV and oxycodone self-administration under an FR5 schedule of reinforcement. RESULTS MDPV was ~ 3-fold more potent at maintaining peak levels of behavior and resulted in greater overall drug intake than oxycodone. High levels of timeout responding were noted in a subset of rats that acquired MDPV self-administration ("high-responders", n = 5), and the FR5 dose-response curve for MDPV was shifted upward for these rats relative to their "low-responder" (n = 6) counterparts. "High-responders" also self-administered more infusions of oxycodone under an FR5 schedule of reinforcement than "low-responders"; however, this was not coupled with increased levels of timeout responding. CONCLUSIONS The present data suggest that a subset of individuals with a history of using synthetic cathinones may be particularly vulnerable to the abuse of oxycodone.
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13
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Jîtcă G, Ősz BE, Tero-Vescan A, Vari CE. Psychoactive Drugs-From Chemical Structure to Oxidative Stress Related to Dopaminergic Neurotransmission. A Review. Antioxidants (Basel) 2021; 10:381. [PMID: 33806320 PMCID: PMC8000782 DOI: 10.3390/antiox10030381] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2021] [Revised: 02/24/2021] [Accepted: 03/01/2021] [Indexed: 12/26/2022] Open
Abstract
Nowadays, more and more young people want to experience illegal, psychoactive substances, without knowing the risks of exposure. Besides affecting social life, psychoactive substances also have an important effect on consumer health. We summarized and analyzed the published literature data with reference to the mechanism of free radical generation and the link between chemical structure and oxidative stress related to dopaminergic neurotransmission. This review presents data on the physicochemical properties, on the ability to cross the blood brain barrier, the chemical structure activity relationship (SAR), and possible mechanisms by which neuronal injuries occur due to oxidative stress as a result of drug abuse such as "bath salts", amphetamines, or cocaine. The mechanisms of action of ingested compounds or their metabolites involve intermediate steps in which free radicals are generated. The brain is strongly affected by the consumption of such substances, facilitating the induction of neurodegenerative diseases. It can be concluded that neurotoxicity is associated with drug abuse. Dependence and oxidative stress are linked to inhibition of neurogenesis and the onset of neuronal death. Understanding the pathological mechanisms following oxidative attack can be a starting point in the development of new therapeutic targets.
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Affiliation(s)
- George Jîtcă
- Department of Pharmacology and Clinical Pharmacy, Faculty of Pharmacy, George Emil Palade University of Medicine, Pharmacy, Science and Technology of Târgu Mureș, 540142 Târgu Mureș, Romania; (G.J.); (C.E.V.)
| | - Bianca E. Ősz
- Department of Pharmacology and Clinical Pharmacy, Faculty of Pharmacy, George Emil Palade University of Medicine, Pharmacy, Science and Technology of Târgu Mureș, 540142 Târgu Mureș, Romania; (G.J.); (C.E.V.)
| | - Amelia Tero-Vescan
- Department of Biochemistry, Faculty of Pharmacy, George Emil Palade University of Medicine, Pharmacy, Science and Technology of Târgu Mureș, 540142 Târgu Mureș, Romania;
| | - Camil E. Vari
- Department of Pharmacology and Clinical Pharmacy, Faculty of Pharmacy, George Emil Palade University of Medicine, Pharmacy, Science and Technology of Târgu Mureș, 540142 Târgu Mureș, Romania; (G.J.); (C.E.V.)
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14
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Holstein SE, Barkell GA, Young MR. Caffeine increases alcohol self-administration, an effect that is independent of dopamine D 2 receptor function. Alcohol 2021; 91:61-73. [PMID: 33429015 DOI: 10.1016/j.alcohol.2020.12.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 12/14/2020] [Accepted: 12/21/2020] [Indexed: 01/09/2023]
Abstract
The rising popularity of alcohol mixed with energy drinks (AmEDs) has become a significant public health concern, with AmED users reporting higher levels of alcohol intake than non-AmED users. One mechanism proposed to explain this heightened level of alcohol intake in AmED users is that the high levels of caffeine found in energy drinks may increase the positive reinforcing properties of alcohol, an effect that may be dependent on interactions between adenosine receptor signaling pathways and the dopamine D2 receptor. Therefore, the purpose of the current study was to confirm whether caffeine does increase the positive reinforcing effects of alcohol using both fixed ratio (FR) and progressive ratio (PR) designs, and to investigate a potential role of the dopamine D2 receptor to caffeine-induced increases in alcohol self-administration. Male Long-Evans rats were trained to self-administer a sweetened alcohol solution (10% v/v alcohol + 2% w/v sucrose) on an FR2 schedule of reinforcement, and the effects of caffeine (0, 5, 10, and 20 mg/kg, i. p. [intraperitoneally]) on the maintenance of alcohol self-administration and alcohol break point were examined. Parallel experiments in rats trained to self-administer sucrose (0.8% w/v) were conducted to determine whether caffeine's reinforcement-enhancing effects extended to a non-drug reinforcer. Caffeine pretreatment (5-10 mg/kg) significantly increased sweetened alcohol self-administration and motivation for a sweetened alcohol reinforcer. However, similar increases in self-administration of a non-drug reinforcer were not observed. Contrary to our hypothesis, the D2 receptor antagonist eticlopride did not block a caffeine-induced increase in sweetened alcohol self-administration, nor did it alter caffeine-induced increases in motivation for a sweetened alcohol reinforcer. Taken together, these results support the hypothesis that caffeine increases the positive reinforcing effects of alcohol, which may explain caffeine-induced increases in alcohol intake. However, the reinforcement-enhancing effects of caffeine appear to be independent of D2 receptor function.
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Affiliation(s)
- Sarah E Holstein
- Department of Psychology, Lycoming College, One College Place, Williamsport, PA, 17701, United States.
| | - Gillian A Barkell
- Department of Psychology, Lycoming College, One College Place, Williamsport, PA, 17701, United States
| | - Megan R Young
- Department of Psychology, Lycoming College, One College Place, Williamsport, PA, 17701, United States
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15
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Doyle MR, Sulima A, Rice KC, Collins GT. Interactions between reinforcement history and drug-primed reinstatement: Studies with MDPV and mixtures of MDPV and caffeine. Addict Biol 2021; 26:e12904. [PMID: 32237282 DOI: 10.1111/adb.12904] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 03/11/2020] [Accepted: 03/19/2020] [Indexed: 11/30/2022]
Abstract
Many drugs of abuse are mixed with other psychoactive substances (e.g., caffeine) prior to their sale or use. Synthetic cathinones (e.g., 3,4-methylenedioxypyrovalerone [MDPV]) are commonly mixed with caffeine or other cathinones (e.g., 3,4-methylenedioxy-N-methylcathinone [methylone]), and these "bath salts" mixtures (e.g., MDPV + caffeine) can exhibit supra-additive interactions with regard to their reinforcing and discriminative stimulus properties. However, little is known about relapse-related effects of drug mixtures. In these studies, male Sprague-Dawley rats self-administered 0.032 mg/kg/inf MDPV or a mixture of MDPV + caffeine (0.029 + 0.66 mg/kg/inf, respectively) and then underwent multiple rounds of extinction and reinstatement testing to evaluate the influence of reinforcement history and drug-associated stimuli on the effectiveness of saline (drug-paired stimuli alone), MDPV (0.032-1.0 mg/kg), caffeine (1.0-32 mg/kg), and mixtures of MDPV:caffeine (in 3:1, 1:1, and 1:3 ratios, relative to each drug's ED50 ) to reinstate responding. Dose-addition analyses were used to determine the nature of the drug-drug interaction for each mixture. MDPV and caffeine dose-dependently reinstated responding and were equally effective, regardless of reinforcement history. Most fixed ratio mixtures of MDPV + caffeine exhibited supra-additive interactions, reinstating responding to levels greater than was observed with caffeine and/or MDPV alone. Drug-associated stimuli also played a key role in reinstating responding, especially for caffeine. Together, these results demonstrate that the composition of drug mixtures can impact relapse-related effects of drug mixtures, and "bath salts" mixtures (MDPV + caffeine) may be more effective at promoting relapse-related behaviors than the constituents alone. Further research is needed to determine how other polysubstance reinforcement histories can impact relapse-related behaviors.
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Affiliation(s)
- Michelle R. Doyle
- Department of Pharmacology The University of Texas Health Science Center at San Antonio San Antonio Texas USA
- Research Service South Texas Veterans Health Care System San Antonio Texas USA
| | - Agnieszka Sulima
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch NIDA and NIAAA Bethesda Maryland USA
| | - Kenner C. Rice
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch NIDA and NIAAA Bethesda Maryland USA
| | - Gregory T. Collins
- Department of Pharmacology The University of Texas Health Science Center at San Antonio San Antonio Texas USA
- Research Service South Texas Veterans Health Care System San Antonio Texas USA
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16
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de Moura FB, Sherwood A, Prisinzano TE, Paronis CA, Bergman J, Kohut SJ. Reinforcing effects of synthetic cathinones in rhesus monkeys: Dose-response and behavioral economic analyses. Pharmacol Biochem Behav 2021; 202:173112. [PMID: 33444603 DOI: 10.1016/j.pbb.2021.173112] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 12/31/2020] [Accepted: 12/31/2020] [Indexed: 12/12/2022]
Abstract
The abuse of synthetic cathinones ("bath salts") with psychomotor stimulant and/or entactogenic properties emerged as a public health concern when they were introduced as "legal" alternatives to drugs of abuse such as cocaine or MDMA. In this study, experiments were conducted in nonhuman primates to examine how differences in transporter selectivity might impact the reinforcing effects of synthetic cathinones. Rhesus monkeys (N = 5) were trained to respond for intravenous injections under a fixed-ratio (FR) 30, timeout 60-s schedule of reinforcement. The reinforcing effects of selected cathinones (e.g., MDPV, αPVP, MCAT, and methylone) with a range of pharmacological effects at dopamine and serotonin transporters were compared to cocaine and MDMA using dose-response analysis under a simple FR schedule and behavioral economic procedures that generated demand curves for two doses of each drug. Results show that one or more doses of all drugs were readily self-administered in each subject and, excepting MDMA (21 injections/session), peak levels of self-administration were similar across drugs (between 30 and 40 injections/session). Demand elasticity for the peak and the peak + 1/2-log dose of each drug did not significantly differ, and when data for the two doses were averaged for each drug, the following rank-order of reinforcing strength emerged: cocaine > MCAT = MDPV = methylone > αPVP = MDMA. These results indicate that the reinforcing strength of synthetic cathinones are not related to their selectivity in binding dopamine or serotonin transporter sites.
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Affiliation(s)
- Fernando B de Moura
- Behavioral Biology Program, McLean Hospital, 115 Mill St., Belmont, MA 02478, USA; Department of Psychiatry, Harvard Medical School, 25 Shattuck St, Boston, MA 02115, USA
| | | | - Thomas E Prisinzano
- College of Pharmacy, University of Kentucky, 789 S. Limestone Street, Lexington, KY 40536, USA
| | - Carol A Paronis
- Behavioral Biology Program, McLean Hospital, 115 Mill St., Belmont, MA 02478, USA; Department of Psychiatry, Harvard Medical School, 25 Shattuck St, Boston, MA 02115, USA
| | - Jack Bergman
- Behavioral Biology Program, McLean Hospital, 115 Mill St., Belmont, MA 02478, USA; Department of Psychiatry, Harvard Medical School, 25 Shattuck St, Boston, MA 02115, USA
| | - Stephen J Kohut
- Behavioral Biology Program, McLean Hospital, 115 Mill St., Belmont, MA 02478, USA; Department of Psychiatry, Harvard Medical School, 25 Shattuck St, Boston, MA 02115, USA.
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17
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Assessment of aversive effects of methylone in male and female Sprague-Dawley rats: Conditioned taste avoidance, body temperature and activity/stereotypies. Neurotoxicol Teratol 2021; 86:106977. [PMID: 33831534 PMCID: PMC9924097 DOI: 10.1016/j.ntt.2021.106977] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 03/22/2021] [Accepted: 03/29/2021] [Indexed: 11/20/2022]
Abstract
Methylone's rewarding effects have been well characterized; however, little is known about its aversive effects and how such effects may be impacted by sex. In this context, the present study investigated the aversive effects of methylone (vehicle, 5.6, 10 or 18 mg/kg, IP) in 35 male and 31 female Sprague-Dawley rats assessed by conditioned taste avoidance and changes in body temperature and activity/stereotypies. Methylone induced significant taste avoidance, changes in temperature and increased activity and stereotypies in both males and females. Similar to work with other synthetic cathinones, methylone has aversive effects as indexed by significant taste avoidance and changes in temperature and activity (two characteristics of methylone overdose in humans). The only endpoint for which there were significant sex differences was in general activity with males displaying a faster onset and females displaying a longer duration. Although sex was not a factor with taste avoidance and temperature, separate analyses for males and females revealed different patterns, e.g., males displayed a more rapid acquisition of taste avoidance and females displayed changes in temperature at lower doses. Males displayed a faster onset and females displayed a longer duration of activity (consistent with the analyses considering sex as a factor), while time- and dose-dependent stereotypies did not show consistent pattern differences. Although sex differences were relatively limited when sex was specifically assessed as a factor (or only evident when sex comparisons were made in the patterns of effects), sex as a biological variable in the study of drugs should be made to determine if differences exist and, if evident, the basis for these differences.
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18
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Clancy L, Philp M, Shimmon R, Fu S. Development and validation of a color spot test method for the presumptive detection of 25-NBOMe compounds. Drug Test Anal 2020; 13:929-943. [PMID: 32744773 DOI: 10.1002/dta.2905] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 07/26/2020] [Accepted: 07/28/2020] [Indexed: 12/12/2022]
Abstract
The great increase of new psychoactive substances over the past decade has substantially transformed the illicit drug industry to an ever-changing dynamic market. 25-NBOMe compounds are just one of these new substance groups that pose a public health risk in many countries around the world. These highly potent, hallucinogenic phenethylamines have previously been sold as "legal highs" or "synthetic LSD" and the necessity to rapidly identify their presence is crucial. While there are many laboratory-based analytical methods capable of identifying these compounds, the lack of presumptive test methods indicates the need for a specific and timely test that could be used in the field. Herein we outline the developed chemical spot test that can selectively identify the presence of 25-NBOMe compounds and related analogs through the reaction with a substituted benzoquinone reagent under basic conditions. This test method has been comprehensively validated showing a high level of selectivity, specificity, and precision with only two other illicit substances producing similar positive results as 25-NBOMe and few false-negative results seen. The working limit of detection was determined to be 225 μg and there was no cross-reactivity from potential adulterants of significance. This test has also been shown to work directly with blotter papers containing 25-NBOMe compounds, indicating no interference from this common matrix and the ability to differentiate these compounds from LSD. This method shows a high potential to be translated to a field compatible test that is simple, rapid, and selective for 25-NBOMe compounds.
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Affiliation(s)
- Laura Clancy
- Centre for Forensic Science, University of Technology Sydney, Ultimo, NSW, Australia
| | - Morgan Philp
- Centre for Forensic Science, University of Technology Sydney, Ultimo, NSW, Australia
| | - Ronald Shimmon
- Centre for Forensic Science, University of Technology Sydney, Ultimo, NSW, Australia
| | - Shanlin Fu
- Centre for Forensic Science, University of Technology Sydney, Ultimo, NSW, Australia
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19
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Gatch MB, Forster MJ. Methylenedioxymethamphetamine-like discriminative stimulus effects of pyrrolidinyl cathinones in rats. J Psychopharmacol 2020; 34:778-785. [PMID: 32536334 DOI: 10.1177/0269881120914213] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Synthetic cathinone derivatives are used as alternatives both for stimulant drugs such as cocaine and methamphetamine and for club drugs such as 3,4-methylenedioxymethamphetamine (MDMA), but little is known about their MDMA-like subjective effects. METHODS In order to determine their similarity to MDMA, the discriminative stimulus effects of 10 pyrrolidinyl cathinones (α-pyrrolidinopropiophenone, 4'-methyl-α-pyrrolidinopropiophenone (4'-MePPP), α-pyrrolidinobutiophenone, 3',4'-methylenedioxy-α-pyrrolidinobutyrophenone (MD-PBP), α-pyrrolidinovalerophenone, 3,4-methylenedioxy-pyrovalerone (MDPV), α-pyrrolidinopentiothiophenone, napthylpyrovalerone (naphyrone), α-pyrrolidinohexiophenone, and 4'-methyl-α-pyrrolidinohexiophenone (4'-MePHP)) were assessed in Sprague-Dawley rats trained to discriminate 1.5 mg/kg racemic ±-MDMA from vehicle. RESULTS Compounds with no substitutions on the phenyl ring and the thiophene produced 44-67% MDMA-appropriate responding. In contrast, the substituted pyrrolidinyl cathinones produced a range of MDMA-appropriate responding dependent upon the length of the alpha side chain. 4'-MePPP, with a single carbon on the alpha position, produced 99.8% MDMA-appropriate responding, MD-PBP (two carbons) produced 83%, naphyrone (three carbons) produced 71%, MDPV (three carbons) produced, 66%, and 4'-MePHP (four carbons) produced 47%. CONCLUSIONS Many cathinone compounds have discriminative stimulus effects similar to those of MDMA. However, the pyrrolidine substitution appears to reduce serotonergic effects, with a commensurate decrease in MDMA-like effects. Substitutions on the phenyl ring appear to be able to restore MDMA-like responding, but only in compounds with short alpha side chains. These findings agree with earlier findings of increasing dopaminergic effects and stronger reinforcing effects with increasing side chain. Assessment of more compounds is necessary to establish the replicability/robustness of this phenomenon. These findings may be of use in predicting which compounds will have MDMA/club drug-like effects versus psychostimulant-like effects.
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Affiliation(s)
- Michael B Gatch
- Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, USA
| | - Michael J Forster
- Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, USA
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Riley AL, Nelson KH, To P, López-Arnau R, Xu P, Wang D, Wang Y, Shen HW, Kuhn DM, Angoa-Perez M, Anneken JH, Muskiewicz D, Hall FS. Abuse potential and toxicity of the synthetic cathinones (i.e., “Bath salts”). Neurosci Biobehav Rev 2020; 110:150-173. [DOI: 10.1016/j.neubiorev.2018.07.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 06/14/2018] [Accepted: 07/24/2018] [Indexed: 01/22/2023]
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Abstract
The opioid epidemic underscores the need for safer and more effective treatments for pain. Combining opioid receptor agonists with drugs that relieve pain through nonopioid mechanisms could be a useful strategy for reducing the dose of opioid needed to treat pain, thereby reducing risks associated with opioids alone. Opioid/cannabinoid mixtures might be useful in this context; individually, opioids and cannabinoids have modest effects on cognition, and it is important to determine whether those effects occur with mixtures. Delay discounting and delayed matching-to-sample tasks were used to examine effects of the mu-opioid receptor agonist morphine (0.32-5.6 mg/kg), the cannabinoid CB1/CB2 receptor agonist CP55940 (0.0032-0.1 mg/kg), and morphine/CP55940 mixtures on impulsivity (n = 3) and memory (n = 4) in rhesus monkeys. Alone, each drug decreased rate of responding without modifying choice in the delay-discounting task, and morphine/CP55940 mixtures reduced choice of one pellet in a delay dependent manner, with monkeys instead choosing delayed delivery of the larger number of pellets. With the exception of one dose in one monkey, accuracy in the delayed matching-to-sample task was not altered by either drug alone. Morphine/CP55940 mixtures decreased accuracy in two monkeys, but the doses in the mixture were equal to or greater than doses that decreased accuracy or response rate with either drug alone. Rate-decreasing effects of morphine/CP55940 mixtures were additive. These data support the notion that opioid/cannabinoid mixtures that might be effective for treating pain do not have greater, and might have less, adverse effects compared with larger doses of each drug alone.
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Collins GT, Sulima A, Rice KC, France CP. Self-administration of the synthetic cathinones 3,4-methylenedioxypyrovalerone (MDPV) and α-pyrrolidinopentiophenone (α-PVP) in rhesus monkeys. Psychopharmacology (Berl) 2019; 236:3677-3685. [PMID: 31346629 PMCID: PMC7274354 DOI: 10.1007/s00213-019-05339-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Accepted: 07/19/2019] [Indexed: 10/26/2022]
Abstract
RATIONALE The availability and abuse of synthetic analogues of cathinone have increased dramatically around the world. Synthetic cathinones, such as 3,4-methylenedioxypyrovalerone [MDPV] and α-pyrrolidinopentiophenone [α-PVP], are cocaine-like inhibitors of monoamine transporters and common constituents of "bath salts" or "flakka" preparations. Studies in rats suggest that MDPV and α-PVP are 3 to 4-fold more effective reinforcers than cocaine; however, comparisons of the relative reinforcing effectiveness of MDPV and α-PVP have not been reported in other species. OBJECTIVES Accordingly, in the present study, 4 adult male rhesus monkeys responding under a progressive ratio schedule of reinforcement were used to characterize the reinforcing effects of MDPV and α-PVP and to compare directly these effects with those of cocaine and methamphetamine. RESULTS MDPV was the most potent reinforcer, followed by α-PVP, methamphetamine, and cocaine. α-PVP was the most effective reinforcer, followed by MDPV, cocaine, and methamphetamine. In addition to making more responses to obtain MDPV and α-PVP, monkeys also responded for longer periods of time when MDPV or α-PVP was available compared with when either cocaine or methamphetamine was available for infusion. CONCLUSIONS These studies confirm recent reports from rodents and provide strong evidence that the synthetic cathinones MDPV and α-PVP are capable of maintaining high levels of responding for prolonged periods of time, and that they function as more effective reinforcers than either cocaine or methamphetamine. The relative strength of these reinforcing effects may account for the high rates of "bath salts" use reported in humans.
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Affiliation(s)
- Gregory T. Collins
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, 78229, USA; Addiction Research, Treatment & Training Center of Excellence, University of Texas Health Science Center at San Antonio, San Antonio, Texas, 78229, USA; South Texas Veterans Health Care System, San Antonio, Texas, 78229, USA
| | - Agnieszka Sulima
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse and National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland, 20850, USA
| | - Kenner C. Rice
- Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse and National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland, 20850, USA
| | - Charles P. France
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas, 78229, USA; Addiction Research, Treatment & Training Center of Excellence, University of Texas Health Science Center at San Antonio, San Antonio, Texas, 78229, USA; Department of Psychiatry, University of Texas Health Science Center at San Antonio, San Antonio, Texas, 78229, USA
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Chen Y, Blough BE, Murnane KS, Canal CE. The synthetic cathinone psychostimulant α-PPP antagonizes serotonin 5-HT 2A receptors: In vitro and in vivo evidence. Drug Test Anal 2019; 11:990-998. [PMID: 30845376 DOI: 10.1002/dta.2582] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/26/2019] [Accepted: 02/27/2019] [Indexed: 01/08/2023]
Abstract
Synthetic cathinones (SCs) are β-keto analogs of amphetamines. Like amphetamines, SCs target monoamine transporters; however, unusual neuropsychiatric symptoms have been associated with abuse of some SCs, suggesting SCs might possess additional pharmacological properties. We performed radioligand competition binding assays to assess the affinities of nine SCs at human 5-HT2A receptors (5-HT2A R) and muscarinic M1 receptors (M1 R) transiently expressed in HEK293 cells. None of the SCs exhibited affinity at M1 R (minimal displacement of [~Kd ] [3 H]scopolamine up to 10 μM). However, two SCs, α-pyrrolidinopropiophenone (α-PPP) and 4-methyl-α-PPP, had low μM Ki values at 5-HT2A R. In 5-HT2A R-phosphoinositide hydrolysis assays, α-PPP and 4-methyl-α-PPP displayed inverse agonist activity. We further assessed the 5-HT2A R functional activity of α-PPP, and observed it competitively antagonized 5-HT2A R signaling stimulated by the 5-HT2 R agonist (±)-2,5-dimethoxy-4-iodoamphetamine (DOI; Kb = 851 nM). To assess in vivo 5-HT2A R activity, we examined the effects of α-PPP on the DOI-elicited head-twitch response (HTR) in mice. α-PPP dose-dependently blocked the HTR with maximal suppression at 10 mg/kg (P < 0.0001), which is a moderate dose used in studies investigating psychostimulant properties of α-PPP. To corroborate a 5-HT2A R mechanism, we also tested 3,4-methylenedioxy-α-PPP (MDPPP) and 3-bromomethcathinone (3-BMC), SCs that we observed had 5-HT2A R Ki s > 10 μM. Neither MDPPP nor 3-BMC, at 10 mg/kg doses, attenuated the DOI HTR. Our results suggest α-PPP has antagonist interactions at 5-HT2A R in vitro that may translate at physiologically-relevant doses in vivo. Considering 5-HT2A R antagonism has been shown to mitigate effects of psychostimulants, this property may contribute to α-PPPs unpopularity compared to other monoamine transporter inhibitors.
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Affiliation(s)
- Yiming Chen
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University, Atlanta, GA, USA
| | - Bruce E Blough
- Center for Drug Discovery, Research Triangle Institute, Research Triangle Park, NC, USA
| | - Kevin S Murnane
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University, Atlanta, GA, USA
| | - Clinton E Canal
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University, Atlanta, GA, USA
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Dopaminergic Effects of Major Bath Salt Constituents 3,4-Methylenedioxypyrovalerone (MDPV), Mephedrone, and Methylone Are Enhanced Following Co-exposure. Neurotox Res 2019; 36:132-143. [PMID: 30879275 DOI: 10.1007/s12640-019-00020-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 02/13/2019] [Accepted: 02/27/2019] [Indexed: 12/21/2022]
Abstract
Designer drug mixtures popularized as "bath salts" often contain the synthetic cathinones 3,4 methylenedioxypyrovalerone (MDPV), mephedrone, and methylone in various combinations. However, most preclinical investigations have only assessed the effects of individual bath salt constituents, and little is known about whether co-exposure to MDPV, mephedrone, and methylone produces significant neuropharmacological interactions. This study evaluated and compared how MDPV, mephedrone, and methylone influence discrete brain tissue dopamine (DA) levels and motor stimulant responses in mice when administered alone and as a ternary mixture. Male adolescent Swiss-Webster mice received intraperitoneal injections of saline or 1 or 10 mg/kg doses of MDPV, mephedrone, or methylone, or a cocktail of all three cathinones at doses of 1, 3.3, or 10 mg/kg each. The effect of each treatment on DA and DA metabolite levels in mesolimbic and nigrostriatal brain tissue was quantified 15 min after a single exposure using HPLC-ECD. Additionally, locomotor activity was recorded in mice after acute (day 1) and chronic intermittent (day 7) dosing. MDPV, mephedrone, and methylone produced dose-related increases in mesolimbic and nigrostriatal DA levels that were significantly enhanced following their co-administration. In addition, mice treated with the cathinone cocktail displayed decreased locomotor activity on day 1 that was exacerbated by day 7 and not observed with any of the drugs alone. Our findings demonstrate a significant enhanced effect of MDPV, mephedrone, and methylone on both DA, and these effects on DA result in significant alterations in locomotor activity.
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Effects of cocaine on the discriminative stimulus and reinforcing effects of mephedrone in male rats. Psychopharmacology (Berl) 2019; 236:1043-1056. [PMID: 30448991 DOI: 10.1007/s00213-018-5110-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 11/05/2018] [Indexed: 12/21/2022]
Abstract
RATIONALE Abuse of cathinones has been a worldwide health concern for some time. Their chemical structures and wide variation in pharmacodynamic effects have led to clinical and preclinical effects that can be both similar to and different from other psychoactive substances such as methylenedioxymethamphetamine (MDMA), methamphetamine, and cocaine. OBJECTIVE The present study examined the discriminative stimulus and reinforcing effects of mephedrone to further characterize the behavioral and pharmacological profile of this first-generation substituted methcathinone. METHODS Rats were trained to discriminate mephedrone (3.2 mg/kg) from saline under a fixed-ratio 20 (FR-20) schedule of food presentation. After establishing dose-effect curves for increasing cumulative doses of mephedrone, substitution tests were conducted with bupropion (5.6-32 mg/kg), cocaine (1.8-18 mg/kg), morphine (0.56-10 mg/kg), and amitriptyline (3.2-32 mg/kg). In addition, cocaine (3.2-18 mg/kg) and the serotonin type-2 (5-HT2) receptor antagonist ritanserin (1, 3.2, and 10 mg/kg) were administered prior to the cumulative doses of mephedrone. Lastly, varying infusion doses of cocaine were substituted for mephedrone in subjects trained to self-administer mephedrone, and varying infusion doses of mephedrone were substituted for cocaine in subjects trained to self-administer cocaine to assess the importance of drug history on the reinforcing effects of mephedrone. RESULTS Of the drugs tested, cocaine had the highest level of mephedrone-lever responding when administered alone (73.5%). In combination with mephedrone, cocaine shifted the mephedrone dose-effect curve upwards in an infra-additive manner. Ritanserin had a small, but non-significant, effect on mephedrone's discriminative stimulus effects. An extensive history (baseline) of cocaine self-administration increased mephedrone self-administration compared to that obtained in mephedrone-trained subjects, whereas a baseline of mephedrone self-administration decreased cocaine self-administration compared to that obtained in cocaine-trained subjects. CONCLUSION The similarity between the discriminative stimulus effects of cocaine and mephedrone in male rats suggests an important overlap and the relative importance of the dopamine (DAT) and serotonin (SERT) transporters. The self-administration data suggest that mephedrone is less reinforcing than cocaine, but that a history of responding for cocaine can increase the reinforcing effects of mephedrone.
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Behavioral economic analysis of the reinforcing effects of "bath salts" mixtures: studies with MDPV, methylone, and caffeine in male Sprague-Dawley rats. Psychopharmacology (Berl) 2019; 236:1031-1041. [PMID: 30267131 PMCID: PMC6440875 DOI: 10.1007/s00213-018-5046-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 09/19/2018] [Indexed: 10/28/2022]
Abstract
RATIONALE "Bath salts" preparations often contain combinations of synthetic cathinones (e.g., 3,4-methylenedioxymethcathinone [methylone], 3,4-methylenedioxypyrovalerone [MDPV]), and caffeine, and evidence suggests that mixtures of synthetic cathinones and caffeine (e.g., MDPV + caffeine or methylone + caffeine) can be more potent and/or effective reinforcers than predicted for an additive interaction. OBJECTIVE To use demand curve analyses to compare the reinforcing effectiveness of MDPV and methylone to mixtures of MDPV + caffeine and methylone + caffeine. METHODS Male Sprague-Dawley rats acquired methylone self-administration (0.32 mg/kg/inf) under a fixed ratio (FR) 1 schedule of reinforcement and generated full dose-response curves for methylone (0.01-1 mg/kg/inf) under an FR5 schedule of reinforcement. Demand curves were then obtained for methylone, MDPV, caffeine, and methylone + caffeine and MDPV + caffeine mixtures by increasing the FR across sessions according to the following series: 3, 10, 18, 32, 56, 100, 178, etc. RESULTS: Self-administration of methylone was rapidly acquired by 87.5% of rats and was maintained across a range of doses, producing an inverted U-shaped dose-response curve. Rank order demand for the individual constituents was MDPV > methylone > caffeine. Demand for the 3:1 (but not 10:1) methylone + caffeine mixture was greater than that for methylone alone, and demand for MDPV alone was similar to both MDPV + caffeine mixtures evaluated. CONCLUSIONS These studies provide additional evidence that although methylone is an effective reinforcer, combining methylone with caffeine results in an enhanced reinforcing effectiveness compared to methylone alone. Thus, abused "bath salts" preparations containing synthetic cathinones and caffeine may have higher abuse liability than preparations containing only synthetic cathinones.
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The abuse-related effects of pyrrolidine-containing cathinones are related to their potency and selectivity to inhibit the dopamine transporter. Neuropsychopharmacology 2018; 43:2399-2407. [PMID: 30305739 PMCID: PMC6180085 DOI: 10.1038/s41386-018-0209-3] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 08/27/2018] [Accepted: 08/28/2018] [Indexed: 11/08/2022]
Abstract
Synthetic cathinones are common constituents of abused "bath salts" preparations and represent a large family of structurally related compounds that function as cocaine-like inhibitors or amphetamine-like substrates of dopamine (DAT), norepinephrine (NET), and serotonin (SERT) transporters. Preclinical evidence suggests that some cathinones (e.g., MDPV and α-PVP) are more effective reinforcers than prototypical stimulant drugs of abuse, such as cocaine or methamphetamine. Although the reinforcing potency of these cathinones is related to their potency to inhibit DAT, less is known about the pharmacological determinants of their unusually high reinforcing effectiveness. To this end, we tested the hypothesis that reinforcing effectiveness of cathinone stimulants is positively correlated with their selectivity for DAT relative to SERT. Uptake inhibition assays in rat brain synaptosomes were used to directly compare the potency of MDPV, MDPBP, MDPPP, α-PVP, α-PPP, and cocaine at DAT, NET, and SERT, whereas intravenous self-administration in rats was used to quantify relative reinforcing effectiveness of the drugs using progressive ratio (PR) and behavioral economic procedures. All cathinones were more potent at DAT than NET or SERT, with a rank order for selectivity at DAT over SERT of α-PVP > α-PPP > MDPV > MDPBP > MDPPP > cocaine. These synthetic cathinones were more effective reinforcers than cocaine, and the measures of reinforcing effectiveness determined by PR and demand curve analyses were highly correlated with selectivity for DAT over SERT. Together, these studies provide strong and convergent evidence that the abuse potential of stimulant drugs is mediated by uptake inhibition at DAT, with activity at SERT serving as a negative modulator of reinforcing effectiveness.
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Collins GT, France CP. Effects of lorcaserin and buspirone, administered alone and as a mixture, on cocaine self-administration in male and female rhesus monkeys. Exp Clin Psychopharmacol 2018; 26:488-496. [PMID: 29952618 PMCID: PMC6162158 DOI: 10.1037/pha0000209] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Cocaine use disorder is a serious public health issue for which there is no effective pharmacotherapy. One strategy to speed development of medications for cocaine use disorder is to repurpose drugs already approved for use in humans based on their ability to interact with targets known to be important for addiction. Two such drugs, lorcaserin (Belviq; a drug with serotonin [5-HT]2C receptor agonist properties) and buspirone (Buspar; a drug with 5-HT1A receptor partial agonist and dopamine D3/D4 receptor antagonist properties) can produce modest decreases in cocaine self-administration in rhesus monkeys. The current study evaluated the effectiveness of mixtures of lorcaserin and buspirone (at fixed dose ratios of 3:1, 1:1, and 1:3 relative to each drug's ID50) to reduce responding for 0.032 mg/kg/inf cocaine under a progressive ratio schedule of reinforcement in 2 male and 2 female rhesus monkeys. Dose addition analyses were used to determine if the effects of the drug mixtures differed from those predicted for an additive interaction between lorcaserin and buspirone. Dose-dependent reductions of cocaine self-administration were observed when lorcaserin and buspirone were administered alone, as well as when they were administered as 3:1, 1:1, and 1:3 fixed ratio mixtures of lorcaserin + buspirone. The effects of the 1:1 mixture of lorcaserin + buspirone on cocaine self-administration were supraadditive, whereas the effects of 3:1 and 1:3 mixtures were additive. Together, these results indicate that a combination therapy containing a mixture of lorcaserin and buspirone might be more effective than either drug alone at treating cocaine use disorder. (PsycINFO Database Record (c) 2018 APA, all rights reserved).
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Affiliation(s)
- Gregory T. Collins
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX, 78229, USA,Addiction Research, Treatment & Training Center of Excellence, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX, 78229, USA,South Texas Veterans Health Care System, 7400 Merton Minter Dr., San Antonio, TX, 78229, USA
| | - Charles P. France
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX, 78229, USA,Addiction Research, Treatment & Training Center of Excellence, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Dr., San Antonio, TX, 78229, USA
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Bessada SM, Alves RC, Oliveira MBP. Caffeine-based food supplements and beverages: Trends of consumption for performance purposes and safety concerns. Food Res Int 2018; 109:310-319. [DOI: 10.1016/j.foodres.2018.04.050] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 04/20/2018] [Accepted: 04/22/2018] [Indexed: 01/12/2023]
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Dolan SB, Chen Z, Huang R, Gatch MB. "Ecstasy" to addiction: Mechanisms and reinforcing effects of three synthetic cathinone analogs of MDMA. Neuropharmacology 2018; 133:171-180. [PMID: 29378213 DOI: 10.1016/j.neuropharm.2018.01.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 12/14/2017] [Accepted: 01/15/2018] [Indexed: 01/30/2023]
Abstract
This study aimed to address the mechanisms and reinforcing effects of three synthetic cathinone analogs of MDMA commonly reported in "Ecstasy" formulations: methylone, butylone, and pentylone. Whole-cell patch clamp techniques were used to assess the mechanism of each compound at the dopamine and serotonin transporters. Separate groups of rats were trained to discriminate methamphetamine, DOM, or MDMA from vehicle. Substitution studies were performed in each group and antagonism studies with SCH23390 were performed against each compound that produced substitution. Self-administration of each compound was evaluated under a progressive ratio schedule of reinforcement. Each compound produced an inward current at the serotonin transporter, but little or no current at the dopamine transporter. Each of the test compounds substituted fully for the discriminative stimulus effects of methamphetamine, methylone and butylone substituted partially for DOM and fully for MDMA, whereas pentylone failed to substitute for DOM and substituted only partially for MDMA. SCH23390 fully and dose-dependently attenuated methamphetamine-appropriate responding produced by each test compound, but was least potent against pentylone. MDMA-appropriate responding was minimally affected by SCH23390. Each test compound was robustly self-administered with pentylone producing the greatest self-administration at the doses tested. Given the prevalence of synthetic cathinones in "Ecstasy" formulations, these data indicate that adulterated "Ecstasy" formulations may drive more compulsive drug use than those containing only MDMA.
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Affiliation(s)
- Sean B Dolan
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, USA.
| | - Zhenglan Chen
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, USA.
| | - Renqi Huang
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, USA.
| | - Michael B Gatch
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, 3500 Camp Bowie Blvd, Fort Worth, TX, USA.
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Gannon BM, Sulima A, Rice KC, Collins GT. Inhibition of Cocaine and 3,4-Methylenedioxypyrovalerone (MDPV) Self-Administration by Lorcaserin Is Mediated by 5-HT2C Receptors in Rats. J Pharmacol Exp Ther 2017; 364:359-366. [PMID: 29217539 PMCID: PMC5787931 DOI: 10.1124/jpet.117.246082] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 11/30/2017] [Indexed: 01/16/2023] Open
Abstract
Lorcaserin is a serotonin (5-HT)2C receptor-preferring agonist approved by the US Food and Drug Administration to treat obesity. Lorcaserin decreases cocaine self-administration in rats and monkeys. Although this effect is partially inhibited by a 5-HT2C receptor antagonist (SB242084), lorcaserin also has effects at 5-HT2A and 5-HT1A receptors, and the relative contribution of these receptors to its anti-cocaine effects has not been investigated. The goals of this study were to determine 1) the potency and effectiveness of lorcaserin to decrease self-administration of cocaine and 3,4-methylenedioxypyrovalerone (MDPV), a common “bath salts” constituent; and 2) the receptor(s) mediating the effects of lorcaserin on cocaine and MDPV self-administration. Male Sprague-Dawley rats (n = 6) were trained to self-administer MDPV under a progressive ratio schedule of reinforcement and maintained under this schedule with daily access to 0.32 mg/kg per infusion of cocaine or 0.032 mg/kg per infusion of MDPV. Dose-response curves for the effects of lorcaserin on cocaine and MDPV self-administration were generated by administering lorcaserin (0.1–5.6 mg/kg) 25 minutes before the start of the session. To assess the effects of 5-HT2C (SB242084, 0.1 mg/kg), 5-HT2A (MDL100907, 0.1 mg/kg), and 5-HT1A (WAY100635, 0.178 mg/kg) receptor antagonists, they were administered 15 minutes before lorcaserin. Lorcaserin decreased cocaine and MDPV self-administration with equal potency. Antagonism of 5-HT2C (but not 5-HT1A or 5-HT2A) receptors blocked the effects of lorcaserin on cocaine and MDPV self-administration. Taken together, these data provide additional support for further development of 5-HT2C receptor agonists, such as lorcaserin, for the treatment of stimulant abuse.
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Affiliation(s)
- Brenda M Gannon
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas (B.M.G., G.T.C.); South Texas Veterans Health Care System, San Antonio, Texas (G.T.C.); and Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse and National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland (A.S., K.C.R.)
| | - Agnieszka Sulima
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas (B.M.G., G.T.C.); South Texas Veterans Health Care System, San Antonio, Texas (G.T.C.); and Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse and National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland (A.S., K.C.R.)
| | - Kenner C Rice
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas (B.M.G., G.T.C.); South Texas Veterans Health Care System, San Antonio, Texas (G.T.C.); and Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse and National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland (A.S., K.C.R.)
| | - Gregory T Collins
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, Texas (B.M.G., G.T.C.); South Texas Veterans Health Care System, San Antonio, Texas (G.T.C.); and Drug Design and Synthesis Section, Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse and National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland (A.S., K.C.R.)
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Gannon BM, Williamson A, Rice KC, Fantegrossi WE. Role of monoaminergic systems and ambient temperature in bath salts constituent 3,4-methylenedioxypyrovalerone (MDPV)-elicited hyperthermia and locomotor stimulation in mice. Neuropharmacology 2017; 134:13-21. [PMID: 28887185 DOI: 10.1016/j.neuropharm.2017.09.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 09/02/2017] [Accepted: 09/04/2017] [Indexed: 02/04/2023]
Abstract
3,4-Methylenedioxypyrovalerone (MDPV) is a common constituent of illicit bath salts products, and in vitro studies implicate monoamine transporters as mediators of its pharmacological effects. Locomotor and thermoregulatory effects of MDPV depend on ambient temperature, so the current studies aimed to gauge the involvement of dopamine (DA), norepinephrine (NE), and serotonin (5-HT) in MDPV-induced locomotor stimulation and hyperthermia in the mouse at different ambient temperatures. Mice were pretreated with the selective 5-HT-reuptake inhibitor fluoxetine (3 mg/kg), the NE-reuptake inhibitor desipramine (3 mg/kg), the DA-reuptake inhibitor bupropion (10 mg/kg), or saline, followed by 10 mg/kg MDPV while thermoregulation and locomotor activity were monitored via radiotelemetry. In other studies, mice were pretreated for three days with saline, 100 mg/kg of the tryptophan hydroxylase inhibitor para-chlorophenylalanine (p-CPA), or 100 mg/kg of the tyrosine hydroxylase inhibitor α-methyl-para-tyrosine (α-MPT) before receiving 10 mg/kg MDPV on the fourth day. All manipulations were conducted at both 20 °C and 28 °C ambient temperatures. MDPV increased locomotor activity under both ambient conditions and modestly increased core body temperature at 20 °C; however, neither pretreatment with monoamine reuptake inhibitors nor monoamine synthesis inhibitors significantly altered these effects. At 28 °C, MDPV induced a more pronounced hyperthermic effect which was attenuated by bupropion, desipramine, or fluoxetine pretreatment, but not by the monoamine synthesis inhibitors. These results suggest that MDPV may have a more complex pharmacological profile than suggested by in vitro studies, perhaps extending beyond interactions with monoamine transporters. A more thorough binding profile of MDPV at various brain recognition sites should be developed. This article is part of the Special Issue entitled 'Designer Drugs and Legal Highs.'
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Affiliation(s)
- Brenda M Gannon
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Adrian Williamson
- College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Kenner C Rice
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse and National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD, 20852, USA
| | - William E Fantegrossi
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA.
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Gannon BM, Galindo KI, Mesmin MP, Sulima A, Rice KC, Collins GT. Relative reinforcing effects of second-generation synthetic cathinones: Acquisition of self-administration and fixed ratio dose-response curves in rats. Neuropharmacology 2017; 134:28-35. [PMID: 28811192 DOI: 10.1016/j.neuropharm.2017.08.018] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Revised: 08/08/2017] [Accepted: 08/10/2017] [Indexed: 10/19/2022]
Abstract
"Bath salts" preparations contain synthetic cathinones which interact with monoamine transporters and function as either monoamine uptake inhibitors or releasers. 3,4-Methylenedioxypyrovalerone (MDPV), 3,4-methylenedioxymethcathinone (methylone), and 4-methylmethcathinone (mephedrone) were three of the most common cathinones (i.e., "first-generation" cathinones); however, after the US Drug Enforcement Administration placed them under Schedule I regulations, they were replaced with structurally related cathinones that were not subject to regulations (i.e., "second-generation" cathinones). Although the reinforcing effects of some second-generation cathinones have been described (e.g., α-pyrrolidinopentiophenone [α-PVP]), little is known about how structural modifications, particularly those involving the methylenedioxy moiety and α-alkyl side chain, impact the abuse liability of other second-generation cathinones (e.g., α-pyrrolidinopropiophenone [α-PPP], 3,4-methylenedioxy-α-pyrrolidinobutiophenone [MDPBP], and 3,4-methylenedioxy-α-pyrrolidinopropiophenone [MDPPP]). The present study used male Sprague-Dawley rats (n = 12 per drug) to directly compare: (1) the acquisition of responding for α-PVP (0.032 mg/kg/inf), α-PPP (0.32 mg/kg/inf), MDPBP (0.1 mg/kg/inf), and MDPPP (0.32 mg/kg/inf) under a fixed ratio (FR) 1 schedule of reinforcement; and (2) full dose-response curves for each drug to maintain responding under an FR5 schedule of reinforcement. The average number of days (∼4 days) and percentage (100%) of rats that acquired self-administration was similar for each drug. The observed rank order potency to maintain responding under an FR5 schedule of reinforcement (α-PVP ≈ MDPBP>α-PPP > MDPPP) is consistent with their potencies to inhibit dopamine uptake. These are the first studies to report on the reinforcing effects of the unregulated second-generation cathinones MDPBP, MDPPP, and α-PPP and indicate all three compounds are readily self-administered, suggesting each possesses high potential for abuse. This article is part of the Special Issue entitled 'Designer Drugs and Legal Highs.'
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Affiliation(s)
- Brenda M Gannon
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Kayla I Galindo
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Melson P Mesmin
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Agnieszka Sulima
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD 20852, USA
| | - Kenner C Rice
- Molecular Targets and Medications Discovery Branch, National Institute on Drug Abuse, National Institute on Alcohol Abuse and Alcoholism, Bethesda, MD 20852, USA
| | - Gregory T Collins
- Department of Pharmacology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; South Texas Veterans Health Care System, San Antonio, TX 78229, USA.
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