1
|
Morris T, Cucinello-Ragland JA, Marks TJ, Prevost K, Glenn JF, Davenport GJ, Edwards S, Winsauer PJ. Distinct antinociceptive and conditioned behavioral effects are produced by individual cannabinoids and a cannabis-derived mixture. Pharmacol Biochem Behav 2024; 235:173692. [PMID: 38128766 DOI: 10.1016/j.pbb.2023.173692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 12/06/2023] [Accepted: 12/14/2023] [Indexed: 12/23/2023]
Abstract
Cannabinoids have been proposed as therapeutics for pain mitigation. Therefore, the antihyperalgesic effects of a proprietary cannabis-derived mixture, Non-Euphoric Phytocannabinoid Elixir #14 (NEPE14), were examined in a persistent Complete Freund's Adjuvant (CFA)-induced model of inflammatory pain. The acute antinociceptive and operant behavioral effects of NEPE14 were then compared with single cannabinoid preparations of Δ9-tetrahydrocannabinol (Δ9-THC), Δ8-THC, the synthetic cannabinoid (-)-CP 55,940 (CP), and cannabidiol (CBD). The THC isomers and CP were also administered with cannabinoid-type-1 receptor (CB1R) antagonist, AM251, and NEPE14 was administered in combination with THC or CP. To induce inflammation, CFA or saline was administered into the paw of male and female Wistar rats. After injections, mechanical hypersensitivity was assessed with Von Frey filaments, and thermal hyperalgesia with a thermal probe. Nine Sprague Dawley rats were also trained to respond under a fixed-ratio 30 schedule for food reinforcers during a 60-min session. Response rates were recorded during the session and warm-water tail-withdrawal latency post session. In CFA-administered rats, mechanical and thermal paw-withdrawal thresholds significantly decreased compared to vehicle, indicating hyperalgesia. Both i.p. (6.6-20.7 ml/kg) and o.m. (30-300 μL) NEPE14 significantly reduced the mechanical and thermal hyperalgesia. In contrast, neither NEPE14 (3.7-20.7 mL/kg i.p., 100-1000 μL o.m.) nor CBD (10-100 mg/kg) significantly decreased response rates or increased tail-withdrawal latency. Acute Δ9-THC, Δ8-THC (1-5.6 mg/kg), and CP (0.032-0.18 mg/kg) significantly and dose-dependently decreased overall response rate and increased tail-withdrawal latency compared to vehicle. AM251 significantly antagonized the rate-decreasing effects of THC, and CP, as well as the antinociceptive effects of CP. Combinations of NEPE14 with Δ9-THC or CP were not significantly different from these cannabinoids alone. In summary, while NEPE14 significantly reduced CFA-induced hyperalgesia, it was more similar to CBD than Δ9-THC, Δ8-THC, and CP for significantly reducing thermal nociception and disrupting conditioned behavior.
Collapse
Affiliation(s)
- Tamara Morris
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, LA 70112, United States of America
| | - Jessica A Cucinello-Ragland
- Department of Physiology, Louisiana State University Health Sciences Center, New Orleans, LA 70112, United States of America
| | - Taylor J Marks
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, LA 70112, United States of America
| | - Kayla Prevost
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, LA 70112, United States of America
| | - John F Glenn
- MilMed R&D Consulting LLC, 1300 Home Farm Court, Brunswick, MD 21716, United States of America
| | - Gregory J Davenport
- Full Spectrum Omega, Inc., 176 S. Alvarado Street, Los Angeles, CA 90057, United States of America
| | - Scott Edwards
- Department of Physiology, Louisiana State University Health Sciences Center, New Orleans, LA 70112, United States of America
| | - Peter J Winsauer
- Department of Pharmacology and Experimental Therapeutics, Louisiana State University Health Sciences Center, New Orleans, LA 70112, United States of America.
| |
Collapse
|
2
|
Mohammad SA, Mousa REA, Gebril SM, Masoud KMM, Radwan RA. Toxic effects of AB-CHMINACA on liver and kidney and detection of its blood level in adult male mice. Forensic Toxicol 2024; 42:7-17. [PMID: 37573525 PMCID: PMC10808145 DOI: 10.1007/s11419-023-00670-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 07/11/2023] [Indexed: 08/15/2023]
Abstract
BACKGROUND AB-CHMINACA is a cannabimimetic indazole derivative. In 2013, it was reported in different countries as a substance of abuse. PURPOSE This study evaluated the subacute toxic effects of AB-CHMINACA on the liver and kidneys and measured its blood level in adult male mice. METHODS The histological and biochemical subacute toxic effects on the liver and kidneys were assessed after four weeks of daily intraperitoneal injections of one of the following doses: 0.3 mg/kg, 3 mg/kg, or 10 mg/kg as the highest dose in adult male albino mice. In addition, the blood concentration level of AB-CHMINACA was determined by GC-MS-MS. RESULTS The histological effects showed congestion, hemorrhage, degeneration, and cellular infiltration of the liver and kidney tissues. Considering the control groups as a reference, biochemical results indicated a significant increase in the serum AST only in the highest dose group, while the ALT and creatinine levels did not significantly change. The mean values of AB-CHMINACA blood levels were 3.05 ± 1.16, 15.08 ± 4.30, and 54.43 ± 8.70 ng/mL for the three treated groups, respectively, one hour after the last dose of intraperitoneal injection. The calibration curves were linear in the 2.5-500 ng/mL concentration range. The intra-assay precision and accuracy of the method were less than 7.0% (RSD) and ± 9.2% (Bias). CONCLUSION This research supports the available case reports on AB-CHMINACA toxicity that it has low lethality; still, the chronic administration causes evident liver and kidney histotoxic effects even at low doses with unnoticeable clinical effects in mice.
Collapse
Affiliation(s)
- Soheir Ali Mohammad
- Department of Forensic Medicine and Clinical Toxicology, Faculty of Medicine, Sohag University, Sohag, Egypt
| | - Rasha Elhaddad Ali Mousa
- Department of Forensic Medicine and Clinical Toxicology, Faculty of Medicine, Sohag University, Sohag, Egypt.
| | | | - Khaled Masoud Mohamed Masoud
- Department of Forensic Sciences, College of Criminal Justice, Naif Arab University for Security Sciences, Riyadh, Saudi Arabia
| | - Rania Ahmad Radwan
- Department of Forensic Medicine and Clinical Toxicology, Faculty of Medicine, Sohag University, Sohag, Egypt
| |
Collapse
|
3
|
Nicotine-induced enhancement of a sensory reinforcer in adult rats: antagonist pretreatment effects. Psychopharmacology (Berl) 2021; 238:475-486. [PMID: 33150479 DOI: 10.1007/s00213-020-05696-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 10/23/2020] [Indexed: 12/21/2022]
Abstract
RATIONALE AND OBJECTIVES The reinforcement-enhancing effect (REE) of nicotine refers to the drug's ability to enhance the strength of other primary and conditioned reinforcers. The main aim was to investigate neuropharmacological mechanisms underlying nicotine's strengthening of a primary visual reinforcer (i.e., a light cue), using a subcutaneous (SC) dose previously shown to provide plasma nicotine levels associated with habitual smoking. METHODS Adult male rats pressed an "active" lever to illuminate a brief cue light during daily 60-min sessions. Rats that showed a clear REE were tested with systemically administered pretreatment drugs followed by nicotine (0.1 mg/kg SC) or saline challenge, in within-subject counterbalanced designs. Pretreatments were mecamylamine (nicotinic, 0.1-1 mg/kg SC), SCH 39166 (D1-like dopaminergic, 0.003-0.2 mg/kg SC), naloxone (opioid, 1 and 5 mg/kg SC), prazosin (alpha1-adrenergic antagonist, 1 and 2 mg/kg IP), rimonabant (CB1 cannabinoid inverse agonist, 3 mg/kg IP), sulpiride (D2-like dopaminergic antagonist, 40 mg/kg SC), or propranolol (beta-adrenergic antagonist, 10 mg/kg IP). RESULTS The nicotine REE was abolished by three antagonists at doses that did not impact motor output, i.e., mecamylamine (1 mg/kg), SCH 39166 (0.01 and 0.03 mg/kg), and naloxone (5 mg/kg). Prazosin and rimonabant both attenuated the nicotine REE, but rimonabant also suppressed responding more generally. The nicotine REE was not significantly altered by sulpiride or propranolol. CONCLUSIONS In adult male rats, the reinforcement-enhancing effect of low-dose nicotine depends on nicotinic receptor stimulation and on neurotransmission via D1/D5 dopaminergic, opioid, alpha1-adrenergic, and CB1 cannabinoid receptors.
Collapse
|
4
|
Feja M, Leigh MPK, Baindur AN, McGraw JJ, Wakabayashi KT, Cravatt BF, Bass CE. The novel MAGL inhibitor MJN110 enhances responding to reward-predictive incentive cues by activation of CB1 receptors. Neuropharmacology 2020; 162:107814. [PMID: 31628934 PMCID: PMC6983961 DOI: 10.1016/j.neuropharm.2019.107814] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 10/14/2019] [Accepted: 10/14/2019] [Indexed: 11/17/2022]
Abstract
CB1 receptor antagonists disrupt operant responding for food and drug reinforcers, and cue-induced reinstatement of cocaine and heroin seeking. Conversely, enhancing endocannabinoid signaling, particularly 2-arachidonyl glycerol (2-AG), by inhibition of monoacyl glycerol lipase (MAGL), may facilitate some aspects of reward seeking. To determine how endocannabinoid signaling affects responding to reward-predictive cues, we employed an operant task that allows us to parse the incentive motivational properties of cues. Rats were required to nosepoke during an intermittent audiovisual incentive cue (IC) to obtain a 10% sucrose reward. The CB1 receptor antagonist, rimonabant, dose-dependently decreased the response ratio (rewarded ICs/total presented) and active nosepokes per IC, while it increased the latency to respond to the cue and obtain the reward, indicating an overall decrease in both the choice and vigor of responding. Yet rats persisted in entering the reward cup. Using a modified version of the task, the novel MAGL inhibitor MJN110 increased the response ratio, decreased the latencies to respond to the IC and enhanced active nosepokes per IC, indicating a facilitation of cue-induced reward seeking. These effects were blocked by a subthreshold dose of rimonabant. Finally, MJN110 did not alter consumption of freely available sucrose within volumes obtained in the operant task. Together these data demonstrate blocking endocannabinoid tone at the CB1 receptor attenuates the ability of cues to induce reward seeking, while some aspects of motivation for the reward are retained. Conversely, enhancing 2-AG signaling at CB1 receptors facilitates IC responding and increases the motivational properties of the IC.
Collapse
Affiliation(s)
- Malte Feja
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, 955 Main St, Buffalo, NY, 14203, USA.
| | - Martin P K Leigh
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, 955 Main St, Buffalo, NY, 14203, USA.
| | - Ajay N Baindur
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, 955 Main St, Buffalo, NY, 14203, USA.
| | - Justin J McGraw
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, 955 Main St, Buffalo, NY, 14203, USA.
| | - Ken T Wakabayashi
- Department of Psychology, University of Nebraska-Lincoln, 1220 T. Street, Lincoln, NE, 68503, USA.
| | - Benjamin F Cravatt
- The Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA.
| | - Caroline E Bass
- Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, 955 Main St, Buffalo, NY, 14203, USA.
| |
Collapse
|
5
|
Venkatesan T, Levinthal DJ, Li BUK, Tarbell SE, Adams KA, Issenman RM, Sarosiek I, Jaradeh SS, Sharaf RN, Sultan S, Stave CD, Monte AA, Hasler WL. Role of chronic cannabis use: Cyclic vomiting syndrome vs cannabinoid hyperemesis syndrome. Neurogastroenterol Motil 2019; 31 Suppl 2:e13606. [PMID: 31241817 PMCID: PMC6788295 DOI: 10.1111/nmo.13606] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Revised: 03/17/2019] [Accepted: 03/25/2019] [Indexed: 12/13/2022]
Abstract
Cannabis is commonly used in cyclic vomiting syndrome (CVS) due to its antiemetic and anxiolytic properties. Paradoxically, chronic cannabis use in the context of cyclic vomiting has led to the recognition of a putative new disorder called cannabinoid hyperemesis syndrome (CHS). Since its first description in 2004, numerous case series and case reports have emerged describing this phenomenon. Although not pathognomonic, a patient behavior called "compulsive hot water bathing" has been associated with CHS. There is considerable controversy about how CHS is defined. Most of the data remain heterogenous with limited follow-up, making it difficult to ascertain whether chronic cannabis use is causal, merely a clinical association with CVS, or unmasks or triggers symptoms in patients inherently predisposed to develop CVS. This article will discuss the role of cannabis in the regulation of nausea and vomiting, specifically focusing on both CVS and CHS, in order to address controversies in this context. To this objective, we have collated and analyzed published case series and case reports on CHS in order to determine the number of reported cases that meet current Rome IV criteria for CHS. We have also identified limitations in the existing diagnostic framework and propose revised criteria to diagnose CHS. Future research in this area should improve our understanding of the role of cannabis use in cyclic vomiting and help us better understand and manage this disorder.
Collapse
Affiliation(s)
- Thangam Venkatesan
- Division of Gastroenterology and HepatologyMedical College of WisconsinMilwaukeeWisconsin
| | - David J. Levinthal
- Division of Gastroenterology, Hepatology, and NutritionUniversity of Pittsburgh Medical CenterPittsburghPennsylvania
| | - B U. K. Li
- Department of PediatricsMedical College of WisconsinMilwaukeeWisconsin
| | - Sally E. Tarbell
- Department of Psychiatry and Behavioral SciencesNorthwestern Feinberg School of MedicineChicagoIllinois
| | | | - Robert M. Issenman
- Division of Pediatric GastroenterologyMcMaster UniversityHamiltonOntarioCanada
| | - Irene Sarosiek
- Division of GastroenterologyTexas Tech University Health Sciences CenterEl PasoTexas
| | | | - Ravi N. Sharaf
- Division of GastroenterologyDepartment of Medicine and Department of Healthcare Policy and ResearchWeill Cornell Medical CenterNew YorkNew York
| | | | | | - Andrew A. Monte
- Department of Emergency MedicineUniversity of Colorado School of MedicineAuroraColorado
| | - William L. Hasler
- Division of GastroenterologyUniversity of Michigan Health SystemAnn ArborMichigan
| |
Collapse
|
6
|
Thompson EE, Jagielo-Miller JE, Vemuri VK, Makriyannis A, McLaughlin PJ. CB1 antagonism produces behaviors more consistent with satiety than reduced reward value in food-maintained responding in rats. J Psychopharmacol 2016; 30:482-91. [PMID: 27005309 PMCID: PMC5531753 DOI: 10.1177/0269881116639287] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Cannabinoid CB1 antagonists are widely known to reduce motivation for food, but it is not known whether they induce satiety or reduce reward value of food. It may therefore be necessary to compare effects of altered satiety and reward food value in the same appetitive task, and determine whether CB1 antagonism produces a behavior pattern similar to either, both, or neither. A fine-grained analysis of fixed-ratio 10 (FR10) responding for palatable food initially included number and duration of, and between, all lever presses and food tray entries in order to differentiate the pattern of suppression of prefeeding from that caused by reducing the reward value of the pellets with quinine. Discriminant function analysis then determined that these manipulations were best differentiated by effects on tray entries, pellet retrieval latencies, and time of the first response. At 0.5 mg/kg, AM 6527 produced similar effects to reducing reward value, but at 1.0 and 4.0 mg/kg, effects were more similar to those when animals were satiated. We conclude that AM 6527 both reduced reward value and enhanced satiety, but as dose increased, effects on satiety became much more prominent. These findings contribute to knowledge about the behavioral processes affected by CB1 antagonism.
Collapse
Affiliation(s)
- Emily E Thompson
- Department of Psychology, Edinboro University of Pennsylvania, Edinboro, PA, USA
| | | | - V Kiran Vemuri
- Center for Drug Discovery, Northeastern University, Boston, MA, USA
| | | | - Peter J McLaughlin
- Department of Psychology, Edinboro University of Pennsylvania, Edinboro, PA, USA
| |
Collapse
|
7
|
Anti-Obesity Effect of the CB2 Receptor Agonist JWH-015 in Diet-Induced Obese Mice. PLoS One 2015; 10:e0140592. [PMID: 26588700 PMCID: PMC4654496 DOI: 10.1371/journal.pone.0140592] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 09/27/2015] [Indexed: 01/24/2023] Open
Abstract
The cannabinoid receptor 2 (CB2) is well known for its immune modulatory role. However, recent localisation of CB2 receptors in metabolically active tissue suggests that the CB2 receptor plays a significant role in energy homeostasis. This study was designed to investigate the impact of chronic CB2 receptor stimulation on food intake, body weight and mood. Lean male C57BL/6 mice were injected i.p. with the selective CB2 receptor agonist, JWH-015 (0.0, 1.0, 5.0 and 10.0 mg kg-1) to establish dose response parameters. Mice made obese following exposure to a diet consisting of 19.4 MJ/kg (4641 Kcal/kg) of energy (19.0% protein, 21.0% total fat, 4.7% crude fiber, and 4.7% AD fiber were given either vehicle or 10 mg/kg JWH-015. Impact on mood, food intake, body weight, plasma metabolites, expression of key metabolic proteins in the brown adipose tissue (BAT) and white adipose tissue (WAT), and markers of inflammation were measured. High dose (10 mg/kg) JWH-015 reduced food intake after 1, 2, 4, and 24 h in lean mice. When given to diet induced obese (DIO) mice, a 10 mg/kg dose of JWH-015 significantly reduced body weight compared to vehicle. This dose led to a shift in markers of lipid metabolism and inflammation in WAT consistent with lipolysis and improved immune response. Furthermore, JWH-015 (10 mg/kg) produced a transient reduction in food intake and significant reduction in fat mass and adipocyte cell size. Importantly, JWH-015 produced an anxiolytic response in the elevated plus maze while having no effect on immobility time in the forced swim test. It should be noted that though the 10 mg/kg dose produced positive effects on the obese state, the possibility that these effects are mediated via non-CB2 receptor mechanisms cannot be ruled out. These results demonstrate a role for CB2 receptors in modulating energy homeostasis and obesity associated metabolic pathologies in the absence of any adverse impact on mood.
Collapse
|
8
|
Nicholson J, Azim S, Rebecchi MJ, Galbavy W, Feng T, Reinsel R, Rizwan S, Fowler CJ, Benveniste H, Kaczocha M. Leptin levels are negatively correlated with 2-arachidonoylglycerol in the cerebrospinal fluid of patients with osteoarthritis. PLoS One 2015; 10:e0123132. [PMID: 25835291 PMCID: PMC4383333 DOI: 10.1371/journal.pone.0123132] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Accepted: 02/16/2015] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND There is compelling evidence in humans that peripheral endocannabinoid signaling is disrupted in obesity. However, little is known about the corresponding central signaling. Here, we have investigated the relationship between gender, leptin, body mass index (BMI) and levels of the endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol (2-AG) in the serum and cerebrospinal fluid (CSF) of primarily overweight to obese patients with osteoarthritis. METHODOLOGY/PRINCIPAL FINDINGS Patients (20 females, 15 males, age range 44-78 years, BMI range 24-42) undergoing total knee arthroplasty for end-stage osteoarthritis were recruited for the study. Endocannabinoids were quantified by liquid chromatography - mass spectrometry. AEA and 2-AG levels in the serum and CSF did not correlate with either age or BMI. However, 2-AG levels in the CSF, but not serum, correlated negatively with CSF leptin levels (Spearman's ρ -0.48, P=0.0076, n=30). No such correlations were observed for AEA and leptin. CONCLUSIONS/SIGNIFICANCE In the patient sample investigated, there is a negative association between 2-AG and leptin levels in the CSF. This is consistent with pre-clinical studies in animals, demonstrating that leptin controls the levels of hypothalamic endocannabinoids that regulate feeding behavior.
Collapse
Affiliation(s)
- James Nicholson
- Department of Orthopedic Surgery, Stony Brook University, Stony Brook, New York, United States of America
| | - Syed Azim
- Department of Anesthesiology, Stony Brook University, Stony Brook, New York, United States of America
| | - Mario J. Rebecchi
- Department of Anesthesiology, Stony Brook University, Stony Brook, New York, United States of America
| | - William Galbavy
- Department of Anesthesiology, Stony Brook University, Stony Brook, New York, United States of America
| | - Tian Feng
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, New York, United States of America
| | - Ruth Reinsel
- Department of Anesthesiology, Stony Brook University, Stony Brook, New York, United States of America
| | - Sabeen Rizwan
- Department of Anesthesiology, Stony Brook University, Stony Brook, New York, United States of America
| | | | - Helene Benveniste
- Department of Anesthesiology, Stony Brook University, Stony Brook, New York, United States of America
- * E-mail: (MK); (HB)
| | - Martin Kaczocha
- Department of Anesthesiology, Stony Brook University, Stony Brook, New York, United States of America
- Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, New York, United States of America
- * E-mail: (MK); (HB)
| |
Collapse
|
9
|
Wiebelhaus JM, Grim TW, Owens RA, Lazenka MF, Sim-Selley LJ, Abdullah RA, Niphakis MJ, Vann RE, Cravatt BF, Wiley JL, Negus SS, Lichtman AH. Δ9-tetrahydrocannabinol and endocannabinoid degradative enzyme inhibitors attenuate intracranial self-stimulation in mice. J Pharmacol Exp Ther 2014; 352:195-207. [PMID: 25398241 DOI: 10.1124/jpet.114.218677] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
A growing body of evidence implicates endogenous cannabinoids as modulators of the mesolimbic dopamine system and motivated behavior. Paradoxically, the reinforcing effects of Δ(9)-tetrahydrocannabinol (THC), the primary psychoactive constituent of cannabis, have been difficult to detect in preclinical rodent models. In this study, we investigated the impact of THC and inhibitors of the endocannabinoid hydrolytic enzymes fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) on operant responding for electrical stimulation of the medial forebrain bundle [intracranial self-stimulation (ICSS)], which is known to activate the mesolimbic dopamine system. These drugs were also tested in assays of operant responding for food reinforcement and spontaneous locomotor activity. THC and the MAGL inhibitor JZL184 (4-[bis(1,3-benzodioxol-5-yl)hydroxymethyl]-1-piperidinecarboxylic acid 4-nitrophenyl ester) attenuated operant responding for ICSS and food, and also reduced spontaneous locomotor activity. In contrast, the FAAH inhibitor PF-3845 (N-3-pyridinyl-4-[[3-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenyl]methyl]-1-piperidinecarboxamide) was largely without effect in these assays. Consistent with previous studies showing that combined inhibition of FAAH and MAGL produces a substantially greater cannabimimetic profile than single enzyme inhibition, the dual FAAH-MAGL inhibitor SA-57 (4-[2-(4-chlorophenyl)ethyl]-1-piperidinecarboxylic acid 2-(methylamino)-2-oxoethyl ester) produced a similar magnitude of ICSS depression as that produced by THC. ICSS attenuation by JZL184 was associated with increased brain levels of 2-arachidonoylglycerol (2-AG), whereas peak effects of SA-57 were associated with increased levels of both N-arachidonoylethanolamine (anandamide) and 2-AG. The cannabinoid receptor type 1 receptor antagonist rimonabant, but not the cannabinoid receptor type 2 receptor antagonist SR144528, blocked the attenuating effects of THC, JZL184, and SA-57 on ICSS. Thus, THC, MAGL inhibition, and dual FAAH-MAGL inhibition not only reduce ICSS, but also decrease other reinforced and nonreinforced behaviors.
Collapse
Affiliation(s)
- Jason M Wiebelhaus
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, Virginia (J.M.W., T.W.G., R.A.O., M.F.L., L.J.S.-S., R.A.A., R.E.V., S.S.N., A.H.L.); Skaggs Institute for Chemical Biology and Department of Chemical Physiology, Scripps Research Institute, La Jolla, California (M.J.N., B.F.C.); and RTI International, Research Triangle Park, North Carolina (J.L.W.)
| | - Travis W Grim
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, Virginia (J.M.W., T.W.G., R.A.O., M.F.L., L.J.S.-S., R.A.A., R.E.V., S.S.N., A.H.L.); Skaggs Institute for Chemical Biology and Department of Chemical Physiology, Scripps Research Institute, La Jolla, California (M.J.N., B.F.C.); and RTI International, Research Triangle Park, North Carolina (J.L.W.)
| | - Robert A Owens
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, Virginia (J.M.W., T.W.G., R.A.O., M.F.L., L.J.S.-S., R.A.A., R.E.V., S.S.N., A.H.L.); Skaggs Institute for Chemical Biology and Department of Chemical Physiology, Scripps Research Institute, La Jolla, California (M.J.N., B.F.C.); and RTI International, Research Triangle Park, North Carolina (J.L.W.)
| | - Matthew F Lazenka
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, Virginia (J.M.W., T.W.G., R.A.O., M.F.L., L.J.S.-S., R.A.A., R.E.V., S.S.N., A.H.L.); Skaggs Institute for Chemical Biology and Department of Chemical Physiology, Scripps Research Institute, La Jolla, California (M.J.N., B.F.C.); and RTI International, Research Triangle Park, North Carolina (J.L.W.)
| | - Laura J Sim-Selley
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, Virginia (J.M.W., T.W.G., R.A.O., M.F.L., L.J.S.-S., R.A.A., R.E.V., S.S.N., A.H.L.); Skaggs Institute for Chemical Biology and Department of Chemical Physiology, Scripps Research Institute, La Jolla, California (M.J.N., B.F.C.); and RTI International, Research Triangle Park, North Carolina (J.L.W.)
| | - Rehab A Abdullah
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, Virginia (J.M.W., T.W.G., R.A.O., M.F.L., L.J.S.-S., R.A.A., R.E.V., S.S.N., A.H.L.); Skaggs Institute for Chemical Biology and Department of Chemical Physiology, Scripps Research Institute, La Jolla, California (M.J.N., B.F.C.); and RTI International, Research Triangle Park, North Carolina (J.L.W.)
| | - Micah J Niphakis
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, Virginia (J.M.W., T.W.G., R.A.O., M.F.L., L.J.S.-S., R.A.A., R.E.V., S.S.N., A.H.L.); Skaggs Institute for Chemical Biology and Department of Chemical Physiology, Scripps Research Institute, La Jolla, California (M.J.N., B.F.C.); and RTI International, Research Triangle Park, North Carolina (J.L.W.)
| | - Robert E Vann
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, Virginia (J.M.W., T.W.G., R.A.O., M.F.L., L.J.S.-S., R.A.A., R.E.V., S.S.N., A.H.L.); Skaggs Institute for Chemical Biology and Department of Chemical Physiology, Scripps Research Institute, La Jolla, California (M.J.N., B.F.C.); and RTI International, Research Triangle Park, North Carolina (J.L.W.)
| | - Benjamin F Cravatt
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, Virginia (J.M.W., T.W.G., R.A.O., M.F.L., L.J.S.-S., R.A.A., R.E.V., S.S.N., A.H.L.); Skaggs Institute for Chemical Biology and Department of Chemical Physiology, Scripps Research Institute, La Jolla, California (M.J.N., B.F.C.); and RTI International, Research Triangle Park, North Carolina (J.L.W.)
| | - Jenny L Wiley
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, Virginia (J.M.W., T.W.G., R.A.O., M.F.L., L.J.S.-S., R.A.A., R.E.V., S.S.N., A.H.L.); Skaggs Institute for Chemical Biology and Department of Chemical Physiology, Scripps Research Institute, La Jolla, California (M.J.N., B.F.C.); and RTI International, Research Triangle Park, North Carolina (J.L.W.)
| | - S Stevens Negus
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, Virginia (J.M.W., T.W.G., R.A.O., M.F.L., L.J.S.-S., R.A.A., R.E.V., S.S.N., A.H.L.); Skaggs Institute for Chemical Biology and Department of Chemical Physiology, Scripps Research Institute, La Jolla, California (M.J.N., B.F.C.); and RTI International, Research Triangle Park, North Carolina (J.L.W.)
| | - Aron H Lichtman
- Department of Pharmacology and Toxicology, Virginia Commonwealth University School of Medicine, Richmond, Virginia (J.M.W., T.W.G., R.A.O., M.F.L., L.J.S.-S., R.A.A., R.E.V., S.S.N., A.H.L.); Skaggs Institute for Chemical Biology and Department of Chemical Physiology, Scripps Research Institute, La Jolla, California (M.J.N., B.F.C.); and RTI International, Research Triangle Park, North Carolina (J.L.W.)
| |
Collapse
|
10
|
Sharkey KA, Darmani NA, Parker LA. Regulation of nausea and vomiting by cannabinoids and the endocannabinoid system. Eur J Pharmacol 2014; 722:134-46. [PMID: 24184696 PMCID: PMC3883513 DOI: 10.1016/j.ejphar.2013.09.068] [Citation(s) in RCA: 123] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 09/22/2013] [Accepted: 09/27/2013] [Indexed: 12/13/2022]
Abstract
Nausea and vomiting (emesis) are important elements in defensive or protective responses that animals use to avoid ingestion or digestion of potentially harmful substances. However, these neurally-mediated responses are at times manifested as symptoms of disease and they are frequently observed as side-effects of a variety of medications, notably those used to treat cancer. Cannabis has long been known to limit or prevent nausea and vomiting from a variety of causes. This has led to extensive investigations that have revealed an important role for cannabinoids and their receptors in the regulation of nausea and emesis. With the discovery of the endocannabinoid system, novel ways to regulate both nausea and vomiting have been discovered that involve the production of endogenous cannabinoids acting centrally. Here we review recent progress in understanding the regulation of nausea and vomiting by cannabinoids and the endocannabinoid system, and we discuss the potential to utilize the endocannabinoid system in the treatment of these frequently debilitating conditions.
Collapse
Affiliation(s)
- Keith A Sharkey
- Hotchkiss Brain Institute, Department of Physiology and Pharmacology, University of Calgary, 3330 Hospital Drive NW, Calgary, AB, Canada T2N 4N1.
| | - Nissar A Darmani
- Department of Basic Medical Sciences, College of Osteopathic Medicine of the Pacific, Western University of Health Sciences, Pomona, CA, USA
| | - Linda A Parker
- Department of Psychology, University of Guelph, Guelph, ON, Canada
| |
Collapse
|
11
|
Casteels C, Gérard N, van Kuyck K, Pottel L, Nuttin B, Bormans G, Van Laere K. Small animal PET imaging of the type 1 cannabinoid receptor in a rodent model for anorexia nervosa. Eur J Nucl Med Mol Imaging 2013; 41:308-21. [PMID: 24006151 DOI: 10.1007/s00259-013-2522-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Accepted: 07/11/2013] [Indexed: 11/29/2022]
Abstract
PURPOSE Several lines of evidence strongly implicate a dysfunctional endocannabinoid system (ECS) in eating disorders. Using [(18)F]MK-9470 and small animal positron emission tomography (PET), we investigated for the first time cerebral changes in type 1 cannabinoid (CB1) receptor binding in vivo in the activity-based rat model of anorexia (ABA), in comparison to distinct motor- and food-related control conditions and in relation to gender and behavioural variables. METHODS In total, experiments were conducted on 80 Wistar rats (23 male and 57 female). Male rats were assigned to the cross-sectional conditions: ABA (n = 12) and CONTROL (n = 11), whereas female rats were divided between two settings: (1) a cross-sectional design using ABA (n = 13), CONTROL (n = 9), and two extra control conditions for each of the variables manipulated in ABA, i.e. DIET (n = 8) and WHEEL (n = 9), and (2) a longitudinal one using ABA (n = 10) and CONTROL (n = 8) studied at baseline, during the model and upon recovery. The ABA group was subjected to food restriction in the presence of a running wheel, the DIET group to food restriction without wheel, the WHEEL group to a normal diet with wheel and CONTROL animals had a normal diet and no running wheel. Parametric CB1 receptor images of each group were spatially normalized to Paxinos space and analysed voxel-wise. RESULTS In the ABA model, absolute [(18)F]MK-9470 binding was significantly increased in all cortical and subcortical brain areas as compared to control conditions (male +67 %; female >51%, all p cluster < 6.3×10(-6)) that normalized towards baseline values after weight gain. Additionally, relative [(18)F]MK-9470 binding was increased in the hippocampus, inferior colliculus and entorhinal cortex of female ABA (+4.6%; p cluster < 1.3×10(-6)), whereas no regional differences were observed in male subjects. Again, relative [(18)F]MK-9470 binding values normalized upon weight gain. CONCLUSION These data point to a widespread transient disturbance of the endocannabinoid transmission, specifically for CB1 receptors in the ABA model. Our data also suggest (1) gender effects on regional CB1 receptor binding in the hippocampus and (2) add further proof to the validity of the ABA model to mimic aspects of human disease.
Collapse
Affiliation(s)
- Cindy Casteels
- Division of Nuclear Medicine, University Hospital and KU Leuven, Herestraat 49 bus 7003, 3000, Leuven, Belgium,
| | | | | | | | | | | | | |
Collapse
|
12
|
Wright FL, Rodgers RJ. Low dose naloxone attenuates the pruritic but not anorectic response to rimonabant in male rats. Psychopharmacology (Berl) 2013; 226:415-31. [PMID: 23142959 DOI: 10.1007/s00213-012-2916-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Accepted: 10/25/2012] [Indexed: 10/27/2022]
Abstract
RATIONALE Previous research suggests that the acute anorectic effect of cannabinoid CB1 receptor antagonist/inverse agonists may be secondary to response competition from the compulsive scratching and grooming syndrome characteristic of these agents. OBJECTIVES As the pruritic effect of rimonabant can be attenuated by the opioid receptor antagonist naloxone, these studies test the prediction that naloxone co-treatment should prevent acute rimonabant anorexia. METHODS Two experiments comprehensively profiled the behavioural effects of an anorectic dose of rimonabant (1.5 mg/kg) in the absence or presence of naloxone (experiment 1: 0.01 or 0.1 mg/kg; experiment 2: 0.05 mg/kg). RESULTS In both experiments, rimonabant not only significantly suppressed food intake and time spent eating but also induced compulsive scratching and grooming. In experiment 1, although the lower dose of naloxone seemed to weakly attenuate the effects of rimonabant both on ingestive and compulsive behaviours, the higher dose more strongly suppressed the compulsive elements but did not significantly affect the anorectic response. The results of experiment 2 showed that naloxone at a dose which markedly attenuated rimonabant-induced grooming and scratching did not alter the effects of the compound on food intake or time spent feeding. The apparent independence of the ingestive and compulsive effects of rimonabant was confirmed by the observation that despite a 'normalising' effect of naloxone co-treatment on behavioural structure (BSS), the opioid antagonist did not impact the suppressant effect of rimonabant on peak feeding. CONCLUSION The acute anorectic response to rimonabant would not appear to be secondary to compulsive scratching and grooming.
Collapse
Affiliation(s)
- F L Wright
- Behavioural Neuroscience Laboratory, Institute of Psychological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | | |
Collapse
|
13
|
Effect of CB1 receptor blockade on food-reinforced responding and associated nucleus accumbens neuronal activity in rats. J Neurosci 2012; 32:11467-77. [PMID: 22895729 DOI: 10.1523/jneurosci.1833-12.2012] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Studies have shown that disruption of cannabinoid receptor signaling reduces operant responses for rewards; yet it is unknown whether changes in neural activity at dopamine terminal regions such as the nucleus accumbens (NAc) underlie these behavioral effects. To study the neural correlates that accompany the disruption of endogenous cannabinoid (eCB) signaling in a food-motivated task, we recorded the neural activity and local field potentials (LFPs) from the NAc. A within-subject design was used for recordings as rats engaged in lever-pressing behavior for sucrose chocolate-flavored pellets delivered during responding in a progressive ratio (PR) schedule of reinforcement. Rats were food restricted to 85 ± 5% of their free body weight and trained under a PR until a stable breakpoint was observed (12 sessions ± 3). Once performance was stable, recordings were made under baseline, vehicle, and following administration of the cannabinoid inverse agonist rimonabant (150 μg/kg, i.v). NAc neurons encoded reward-predictive cues as well as food reward delivery. Rimonabant administration robustly reduced breakpoints in all rats tested, as previously reported. We found that this reduction is accompanied by a profound attenuation in the strength and coordination of specific event-related spiking activity. Moreover, rimonabant decreased LFP gamma power at 80 Hz (high gamma) at reward delivery and gamma power at 50 Hz (low gamma) at cue onset. Together the present results indicate that the eCB system sculpts neural activity patterns that accompany PR performance and reward consumption.
Collapse
|
14
|
Wiley JL, Marusich JA, Zhang Y, Fulp A, Maitra R, Thomas BF, Mahadevan A. Structural analogs of pyrazole and sulfonamide cannabinoids: effects on acute food intake in mice. Eur J Pharmacol 2012; 695:62-70. [PMID: 22975289 DOI: 10.1016/j.ejphar.2012.08.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 08/24/2012] [Accepted: 08/27/2012] [Indexed: 12/31/2022]
Abstract
Obesity contributes to a multitude of serious health problems. Given the demonstrated role of the endogenous cannabinoid system in appetite regulation, the purpose of the present study was to evaluate structural analogs of two cannabinoids, rimonabant (cannabinoid CB(1) receptor antagonist) and O-2050 (sulfonamide analog of Δ(8)-tetrahydrocannabinol), that showed appetite suppressant effects in previous studies. Structure-activity relationships of these two lead compounds were examined in several assays, including cannabinoid CB(1) and CB(2) receptor binding, food intake, and an in vivo test battery (locomotor activity, antinociception, ring immobility, and body temperature) in mice. Rimonabant and O-2050 reliably decreased feeding in mice; however, their analogs decreased feeding only at higher doses, even though some compounds had quite good cannabinoid CB(1) binding affinity. Results of the in vivo test battery were inconsistent, with some of the compounds producing effects characteristic of cannabinoid agonists while other compounds were inactive or were antagonists against an active dose of Δ(9)-tetrahydrocannabinol. These results demonstrate that reduction of food intake is not a characteristic effect of pyrazole and sulfonamide cannabinoid analogs with favorable cannabinoid CB(1) binding affinity, suggesting that development of these classes of cannabinoids for the treatment of obesity will require evaluation of their effects in a broad spectrum of pharmacological assays.
Collapse
Affiliation(s)
- Jenny L Wiley
- Research Triangle Institute, 3040 Cornwallis Drive, Research Triangle Park, NC 27709-2194, U.S.A.
| | | | | | | | | | | | | |
Collapse
|
15
|
Marusich JA, Wiley JL. Rimonabant abolishes sensitivity to workload changes in a progressive ratio procedure. Pharmacol Biochem Behav 2012; 101:575-80. [PMID: 22425597 PMCID: PMC3387812 DOI: 10.1016/j.pbb.2012.03.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 02/29/2012] [Accepted: 03/04/2012] [Indexed: 10/28/2022]
Abstract
Despite its propensity to increase motivation for food consumption, marijuana use in humans has been associated with "amotivational syndrome." This "amotivational syndrome" can be characterized by a reduction in response persistence in tasks requiring sustained, but not maximal, effort. To examine this hypothesis, dose-effect functions for THC (0.03-10 mg/kg) and rimonabant (0.1-10 mg/kg) were first determined under a time-constrained PR 5 schedule. During the second phase of the study, doses of THC and rimonabant that did not affect the responses/total reinforced responses were chosen for further evaluation in a series of PR schedules with step sizes of PR 3, PR 5, PR 10, and PR exponential. THC and rimonabant produced decreases in responses per reinforcer, and response rate when behavior was maintained on a PR 5. Rimonabant also decreased session length. During the PR step size manipulation phase, rimonabant decreased responses/total reinforced responses, response rate, and session length, whereas THC only decreased response rate. These results are consistent with previous literature demonstrating that rimonabant decreases motivation for food both in cases where it is earned, as well as under free-feeding conditions, whereas the effects of cannabinoid agonists such as THC on responding for food exhibit greater dependence upon motivational and non-motivational factors, including workload and duration of the task.
Collapse
Affiliation(s)
- Julie A Marusich
- Discovery Sciences, Pharmacology and Toxicology, RTI International, 3040 Cornwallis Rd, Research Triangle Pk, NC 27709, USA.
| | | |
Collapse
|
16
|
Loewinger GC, Beckert MV, Tejeda HA, Cheer JF. Methamphetamine-induced dopamine terminal deficits in the nucleus accumbens are exacerbated by reward-associated cues and attenuated by CB1 receptor antagonism. Neuropharmacology 2012; 62:2192-201. [PMID: 22306525 DOI: 10.1016/j.neuropharm.2012.01.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2011] [Revised: 12/24/2011] [Accepted: 01/18/2012] [Indexed: 01/28/2023]
Abstract
Methamphetamine (METH) exposure is primarily associated with deleterious effects to dopaminergic neurons. While several studies have implicated the endocannabinoid system in METH's locomotor, rewarding and neurochemical effects, a role for this signaling system in METH's effects on dopamine terminal dynamics has not been elucidated. Given that CB1 receptor blockade reduces the acute potentiation of phasic extracellular dopamine release from other psychomotor stimulant drugs and that the degree of acute METH-induced increases in extracellular dopamine levels is related to the severity of dopamine depletion, we predicted that pretreatment with the CB1 receptor antagonist rimonabant would reduce METH-induced alterations at dopamine terminals. Furthermore, we hypothesized that administration of METH in environments where reward associated-cues were present would potentiate METH's acute effects on dopamine release in the nucleus accumbens and exacerbate changes in dopamine terminal activity. Fast-scan cyclic voltammetry was used to measure electrically-evoked dopamine release in the nucleus accumbens and revealed markers of compromised dopamine terminal integrity nine days after a single dose of METH. These were exacerbated in animals that received METH in the presence of reward-associated cues, and attenuated in rimonabant-pretreated animals. While these deficits in dopamine dynamics were associated with reduced operant responding on days following METH administration in animals treated with only METH, rimonabant-pretreated animals exhibited levels of operant responding comparable to control. Moreover, dopamine release correlated significantly with changes in lever pressing behavior that occurred on days following METH administration. Together these data suggest that the endocannabinoid system is involved in the subsecond dopaminergic response to METH.
Collapse
Affiliation(s)
- Gabriel C Loewinger
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn Street, Baltimore, MD 21201, USA
| | | | | | | |
Collapse
|
17
|
Hernandez G, Bernstein D, Schoenbaum G, Cheer JF. Contrasting Effects of Lithium Chloride and CB1 Receptor Blockade on Enduring Changes in the Valuation of Reward. Front Behav Neurosci 2011; 5:53. [PMID: 21922005 PMCID: PMC3167146 DOI: 10.3389/fnbeh.2011.00053] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Accepted: 08/13/2011] [Indexed: 01/16/2023] Open
Abstract
When an organism responds for a reward, its learned behavior can be characterized as goal-directed or habitual based on whether or not it is susceptible to reward devaluation. Here, we evaluated whether instrumental responding for brain stimulation reward (BSR) can be devalued using a paradigm traditionally used for natural rewards. Rats were trained to lever press for BSR; afterward, BSR was paired with either lithium chloride (LiCl, 5 mg/kg, i.p.), a pro-emetic, or AM251, a CB1 receptor antagonist (3 mg/kg, i.p.) or the vehicle of these compounds. Pairings of BSR with these compounds and their vehicles were performed in a novel environment so that only unconditional effects of BSR would be affected by the pharmacological manipulations. Subsequently, in a probe test, all rats were returned in the drug-free state to the boxes where they had received training and instrumental responding was reassessed in the absence of BSR delivery. When compared to control, LiCl produced a significant decrease in the number of responses during the test session, whereas AM251 did not. These results show that instrumental responding for BSR is susceptible to devaluation, in accord with the proposal that this behavior is supported at least in part by associations between the response and the rewarding outcome. Further, they suggest that reward modulation observed in studies involving the use of CB1 receptor antagonists arises from changes in the organism’s motivation rather than drug-induced changes in the intrinsic value of reward.
Collapse
|
18
|
Hernandez G, Cheer JF. Extinction learning of rewards in the rat: is there a role for CB1 receptors? Psychopharmacology (Berl) 2011; 217:189-97. [PMID: 21519986 PMCID: PMC3161161 DOI: 10.1007/s00213-011-2275-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Accepted: 03/15/2011] [Indexed: 10/18/2022]
Abstract
RATIONALE Endocannabinoids have been widely studied in the context of addiction and reward due to their role in reinstatement. However, little is known about the role of CB1 receptors during extinction learning of an appetitively motivated task. OBJECTIVE The aim of this study was to evaluate the role of endocannabinoids at different stages of extinction learning. METHODS Endocannabinoid signaling was disrupted by injecting the CB1 receptor antagonist rimonabant (0, 200, 300 μg/kg i.v.) during the acquisition or consolidation phases of learning. The rate of extinction and its half-life were analyzed, as well as food-seeking in a reward-induced reinstatement test. We further investigated the interaction between extinction and endocannabinoids in different groups of rats that received drug treatments but did not undergo extinction training (abstinence). In addition, the effects of rimonabant on cue retrieval were investigated in a cue-induced reinstatement test in which rimonabant (0, 300 μg/kg i.v.) was given immediately prior to the reinstatement session. RESULTS Blockade of CB1 receptors during acquisition or consolidation of extinction learning had no effect on the rate extinction or its half-life and these pretreatments had no long term consequences on reward-seeking behavior. Furthermore, rats that underwent extinction training responded at lower levels than those that received the drug in the absence of extinction (p = 0.000, η (2) = 0.40). Rimonabant was effective in inhibiting behavior only if it was immediately given before a cue-induced reinstatement session (p = 0.000, η (2) = 0.92). CONCLUSION The present results clarify and isolate the role of endocannabinoids in reinstatement as key mediators of cue retrieval, rather than orchestrators of extinction learning processes.
Collapse
Affiliation(s)
- Giovanni Hernandez
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, 20 Penn Street, Baltimore, MD 2120, USA.
| | | |
Collapse
|
19
|
Cannabinoid receptor blockade reduces the opportunity cost at which rats maintain operant performance for rewarding brain stimulation. J Neurosci 2011; 31:5426-35. [PMID: 21471378 DOI: 10.1523/jneurosci.0079-11.2011] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
There is ample evidence that blockade of CB(1) receptors reduces reward seeking. However, the reported effects of CB(1) blockade on performance for rewarding electrical brain stimulation stand out as an exception. By applying a novel method for conceptualizing and measuring reward seeking, we show that AM-251, a CB(1) receptor antagonist, does indeed decrease performance for rewarding electrical stimulation of the medial forebrain bundle in rats. Reward seeking depends on multiple sets of variables, including the intensity of the reward, its cost, and the value of competing rewards. In turn, reward intensity depends both on the sensitivity and gain of brain reward circuitry. We show that drug-induced changes in sensitivity cannot account for the suppressive effect of AM-251 on reward seeking. Therefore, the role of CB(1) receptors must be sought among the remaining determinants of performance. Our analysis provides an explanation of the inconsistencies between prior reports, which likely arose from the following: (1) the averaging of data across subjects showing heterogeneous effects and (2) the use of methods that cannot distinguish between the different determinants of reward pursuit. By means of microdialysis, we demonstrate that blockade of CB(1) receptors attenuates nucleus accumbens dopamine release in response to rewarding medial forebrain bundle stimulation, and we propose that this action is responsible for the ability of the drug to decrease performance for the electrical reward.
Collapse
|
20
|
Cluny NL, Vemuri VK, Chambers AP, Limebeer CL, Bedard H, Wood JT, Lutz B, Zimmer A, Parker LA, Makriyannis A, Sharkey KA. A novel peripherally restricted cannabinoid receptor antagonist, AM6545, reduces food intake and body weight, but does not cause malaise, in rodents. Br J Pharmacol 2011; 161:629-42. [PMID: 20880401 DOI: 10.1111/j.1476-5381.2010.00908.x] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND AND PURPOSE Cannabinoid CB(1) receptor antagonists reduce food intake and body weight, but clinical use in humans is limited by effects on the CNS. We have evaluated a novel cannabinoid antagonist (AM6545) designed to have limited CNS penetration, to see if it would inhibit food intake in rodents, without aversive effects. EXPERIMENTAL APPROACH Cannabinoid receptor binding studies, cAMP assays, brain penetration studies and gastrointestinal motility studies were carried out to assess the activity profile of AM6545. The potential for AM6545 to induce malaise in rats and the actions of AM6545 on food intake and body weight were also investigated. KEY RESULTS AM6545 binds to CB(1) receptors with a K(i) of 1.7 nM and CB(2) receptors with a K(i) of 523 nM. AM6545 is a neutral antagonist, having no effect on cAMP levels in transfected cells and was less centrally penetrant than AM4113, a comparable CB(1) receptor antagonist. AM6545 reversed the effects of WIN55212-2 in an assay of colonic motility. In contrast to AM251, AM6545 did not produce conditioned gaping or conditioned taste avoidance in rats. In rats and mice, AM6545 dose-dependently reduced food intake and induced a sustained reduction in body weight. The effect on food intake was maintained in rats with a complete subdiaphragmatic vagotomy. AM6545 inhibited food intake in CB(1) receptor gene-deficient mice, but not in CB(1)/CB(2) receptor double knockout mice. CONCLUSIONS AND IMPLICATIONS Peripherally active, cannabinoid receptor antagonists with limited brain penetration may be useful agents for the treatment of obesity and its complications.
Collapse
Affiliation(s)
- N L Cluny
- Department of Physiology & Pharmacology, Hotchkiss Brain Institute and Snyder Institute of Infection, Immunity and Inflammation, University of Calgary, AB, Canada
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Antagonism of ∆⁹-THC induced behavioral effects by rimonabant: time course studies in rats. Eur J Pharmacol 2010; 648:133-8. [PMID: 20854804 DOI: 10.1016/j.ejphar.2010.09.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Revised: 08/11/2010] [Accepted: 09/06/2010] [Indexed: 01/09/2023]
Abstract
The objective was to examine the time course of the cannabinoid 1 receptor antagonist/inverse agonist rimonabant's ability to antagonize in vivo cannabinergic agonist effects. We used two behavioral procedures sensitive to the effects of ∆⁹-tetrahydrocannabinol (∆⁹-THC): rat drug discrimination (EXP-1) and suppression of fixed-ratio responding (FR) for food reinforcement (EXP-2). Two training doses of ∆⁹-THC (1.8 and 3 mg/kg) served as discriminative cues in two groups discriminating ∆⁹-THC from vehicle; injections were i.p. 20 min before session onset. Tests assessed the dose-response functions of ∆⁹-THC and the time course for rimonabant in its ability to block the discriminative stimulus effects of ∆⁹-THC. For antagonism testing, the training doses of ∆⁹-THC were used and the rimonabant dose was 1mg/kg. Tests were 20, 60, 120, and 240 min post rimonabant administration; ∆⁹-THC was always administered 20 min prior to testing. For EXP-2, only one response lever was activated and every 10th (FR-10) press on that lever resulted in food delivery. Once the response rate stabilized, tests occurred with ∆⁹-THC, rimonabant and combinations of the drugs. The ED(50) estimates for the dose-response functions were 0.38 (±0.28-0.51) and 0.50 (±0.40-0.63) mg/kg for the training doses of 1.8 and 3 mg/kg ∆⁹-THC, respectively. The time course studies suggested functional half-life estimates of 128.4 (±95.7-172.2) and 98.4 (±64.2-150.7) min by rimonabant for the two groups in EXP-1, respectively. Similarly, the functional half-life of rimonabant was 118.9 (±66.1-213.9) min in EXP-2. Thus, antagonism of ∆⁹-THC by rimonabant is relatively short lasting.
Collapse
|
22
|
Izzo AA, Sharkey KA. Cannabinoids and the gut: new developments and emerging concepts. Pharmacol Ther 2010; 126:21-38. [PMID: 20117132 DOI: 10.1016/j.pharmthera.2009.12.005] [Citation(s) in RCA: 301] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Accepted: 12/24/2009] [Indexed: 12/11/2022]
Abstract
Cannabis has been used to treat gastrointestinal (GI) conditions that range from enteric infections and inflammatory conditions to disorders of motility, emesis and abdominal pain. The mechanistic basis of these treatments emerged after the discovery of Delta(9)-tetrahydrocannabinol as the major constituent of Cannabis. Further progress was made when the receptors for Delta(9)-tetrahydrocannabinol were identified as part of an endocannabinoid system, that consists of specific cannabinoid receptors, endogenous ligands and their biosynthetic and degradative enzymes. Anatomical, physiological and pharmacological studies have shown that the endocannabinoid system is widely distributed throughout the gut, with regional variation and organ-specific actions. It is involved in the regulation of food intake, nausea and emesis, gastric secretion and gastroprotection, GI motility, ion transport, visceral sensation, intestinal inflammation and cell proliferation in the gut. Cellular targets have been defined that include the enteric nervous system, epithelial and immune cells. Molecular targets of the endocannabinoid system include, in addition to the cannabinoid receptors, transient receptor potential vanilloid 1 receptors, peroxisome proliferator-activated receptor alpha receptors and the orphan G-protein coupled receptors, GPR55 and GPR119. Pharmacological agents that act on these targets have been shown in preclinical models to have therapeutic potential. Here, we discuss cannabinoid receptors and their localization in the gut, the proteins involved in endocannabinoid synthesis and degradation and the presence of endocannabinoids in the gut in health and disease. We focus on the pharmacological actions of cannabinoids in relation to GI disorders, highlighting recent data on genetic mutations in the endocannabinoid system in GI disease.
Collapse
Affiliation(s)
- Angelo A Izzo
- Department of Experimental Pharmacology, University of Naples Federico II and Endocannabinoid Research Group, Naples, Italy.
| | | |
Collapse
|
23
|
Mazzoni O, Diurno MV, di Bosco AM, Novellino E, Grieco P, Esposito G, Bertamino A, Calignano A, Russo R. Synthesis and pharmacological evaluation of analogs of indole-based cannabimimetic agents. Chem Biol Drug Des 2009; 75:106-14. [PMID: 19895505 DOI: 10.1111/j.1747-0285.2009.00910.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Aminoalkylindoles (AAIs), although structurally dissimilar from the classical cannabinoids, are known to be capable of binding to cannabinoid receptors and of evoking cannabinomimetic responses. With the aim of investigating the structure-activity relationships (SAR) for the binding of non-classical agonists to CB1 and CB2 cannabinoid receptors, we designed and synthesized a series of indole derivatives. The compounds were tested for their analgesic action by formalin test and compared to WIN 55212-2, an AAI acting to the cannabinoid receptors. In receptor binding assay, compound 5 showed affinity for the CB1 receptor comparable to WIN 55212-2.
Collapse
Affiliation(s)
- Orazio Mazzoni
- Dipartimento di Chimica Farmaceutica e Tossicologica, Via D. Montesano 49 Università di Napoli Federico II, Naples, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Duvivier VF, Delafoy-Plasse L, Delion V, Lechevalier P, Le Bail JC, Guillot E, Pruniaux MP, Galzin AM. Beneficial effect of a chronic treatment with rimonabant on pancreatic function and β-cell morphology in Zucker Fatty rats. Eur J Pharmacol 2009; 616:314-20. [DOI: 10.1016/j.ejphar.2009.05.024] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Revised: 05/15/2009] [Accepted: 05/19/2009] [Indexed: 11/16/2022]
|
25
|
Delta-9-tetrahydrocannabinol enhances food reinforcement in a mouse operant conflict test. Psychopharmacology (Berl) 2009; 205:475-87. [PMID: 19452141 DOI: 10.1007/s00213-009-1557-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2008] [Accepted: 04/23/2009] [Indexed: 02/05/2023]
Abstract
RATIONALE Cannabinoid compounds are known to regulate feeding behavior by modulating the hedonic and/or the incentive properties of food. OBJECTIVES The aim of this work was to determine the involvement of the cannabinoid system in food reinforcement associated with a conflict situation generated by stress. METHODS Mice were trained on a fixed ratio 1 schedule of reinforcement to obtain standard, chocolate-flavored or fat-enriched pellets. Once the acquisition criteria were achieved, the reinforced lever press was paired with foot-shock exposure, and the effects of Delta(9)-tetrahydrocannabinol (THC; 1 mg/kg) were evaluated in this conflict paradigm. RESULTS THC did not modify the operant response in mice trained with standard pellets. In contrast, THC improved the instrumental performance of mice trained with chocolate-flavored and fat-enriched pellets. However, the cannabinoid agonist did not fully restore the baseline responses obtained previous to foot-shock delivery. THC ameliorated the performance to obtain high palatable food in this conflict test in both food-restricted and sated mice. The effects of THC on food reinforcement seem to be long-lasting since mice previously treated with this compound showed a better recovery of the instrumental behavior after foot-shock exposure. CONCLUSIONS These findings reveal that the cannabinoid system is involved in the regulation of goal-directed responses towards high palatable and high caloric food under stressful situations.
Collapse
|
26
|
Jelsing J, Galzin AM, Guillot E, Pruniaux MP, Larsen PJ, Vrang N. Localization and phenotypic characterization of brainstem neurons activated by rimonabant and WIN55,212-2. Brain Res Bull 2009; 78:202-10. [DOI: 10.1016/j.brainresbull.2008.10.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Revised: 10/21/2008] [Accepted: 10/27/2008] [Indexed: 11/25/2022]
|
27
|
Malinen H, Hyytiä P. Ethanol self-administration is regulated by CB1 receptors in the nucleus accumbens and ventral tegmental area in alcohol-preferring AA rats. Alcohol Clin Exp Res 2008; 32:1976-83. [PMID: 18782338 DOI: 10.1111/j.1530-0277.2008.00786.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Endogenous cannabinoids and their receptors, CB1 receptors in particular, have been implicated in mediation of ethanol reinforcement. Previously, suppression of ethanol drinking by CB1 antagonists has been demonstrated in many experimental paradigms. However, the exact mechanism by which CB1 antagonists modulate ethanol drinking remains elusive. In the present study, we assessed the role of CB1 receptors within the key regions of the mesolimbic dopamine pathway, the nucleus accumbens (NAcc) and ventral tegmental area (VTA), in regulation of ethanol self-administration. METHODS Adult male alcohol-prefer AA rats were trained to self-administer either 10% (w/v) ethanol or 0.1% (w/v) saccharin under an FR1 schedule during daily 30-minute sessions. Following stable baseline responding, rats were tested after systemic administration of the CB1 antagonist SR141716A (0 to 10 mg/kg) and the agonist WIN55,212-2 (0 to 2 mg/kg). Separate groups of rats were implanted with bilateral cannulas aimed at the NAcc or VTA, and tested after microinjections of SR141716A (0 to 3 microg) and WIN55,212-2 (0 to 5 microg) into the NAcc or VTA. The highest intracerebral doses were tested also in rats responding for a 0.1% saccharin solution. RESULTS SR141617A dose-dependently suppressed ethanol responding after systemic administration. Microinjections of SR141617A both into NAcc and VTA attenuated ethanol responding. In addition, intra-NAcc injections of SR141617A suppressed saccharin intake. Although low doses of systemically given WIN55,212-2 increased ethanol responding, no effects were seen after WIN55,212-2 microinjections into NAcc or VTA. CONCLUSIONS Bidirectional changes in ethanol self-administration by the systematically administered CB1 agonist and antagonist show that ethanol reinforcement is controlled by CB1 receptors in alcohol-preferring AA rats. Replication of the suppressive effects by CB1 antagonism in the NAcc and VTA suggests that endocannabinoids and their receptors mediate ethanol reinforcement through interaction with the mesolimbic dopamine pathway.
Collapse
Affiliation(s)
- Hanna Malinen
- National Public Heath Institute, Department of Mental Health and Alcohol Research, Helsinki, Finland
| | | |
Collapse
|
28
|
Järbe TUC, LeMay BJ, Olszewska T, Vemuri VK, Wood JT, Makriyannis A. Intrinsic effects of AM4113, a putative neutral CB1 receptor selective antagonist, on open-field behaviors in rats. Pharmacol Biochem Behav 2008; 91:84-90. [PMID: 18640150 DOI: 10.1016/j.pbb.2008.06.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2007] [Revised: 06/06/2008] [Accepted: 06/24/2008] [Indexed: 12/26/2022]
Abstract
We examined open-field effects in rats of the cannabinoid 1 receptor (CB1R) agonist WIN55,212-2 (WIN; 3 mg/kg) and its interaction with the CB1R putative neutral antagonist AM4113 (0.3 to 3 mg/kg). Separate studies examined AM4113 alone (0.3 to 5.6 mg/kg). Unlike the CB1R antagonist rimonabant, in vitro (e.g., [Sink K.S., McLaughlin P.J., Wood J.A., Brown C., Fan P., Vemuri V.K., Pang Y., Olzewska T., Thakur G.A., Makriyannis A., Parker L.A., Salamone J.D. The novel cannabinoid CB(1) receptor neutral antagonist AM4113 suppresses food intake and food-reinforced behavior but does not induce signs of nausea in rats. Neuropsychopharmacology 2008a; 33: 946-955.; Sink K.S., Vemuri V.K., Olszewska T., Makriyannis A., Salamone J.D. Cannabinoid CB1 antagonists and dopamine antagonists produce different effects on a task involving response allocation and effort-related choice in food-seeking behavior. Psychopharmacology (Berl) 2008b; 196: 565-574.]) AM4113 produced no change in cAMP accumulation (neutral antagonism vis-a-vis inverse agonism). Recorded behaviors were: ambulation, rearing, circling, latency, scratching, grooming, defecation, urination and vocalization/squeaking. WIN reduced ambulation and rearing; AM4113 completely (ambulation) or partially (rearing) antagonized these behaviors. WIN alone resulted in circling and an increased latency to leave the start area; effects blocked by AM4113. AM4113 increased scratching and grooming, effects attenuated but not abolished by WIN. AM4113 alone tended to reduce ambulation and rearing and had no effect on latency or circling. AM4113 alone increased scratching and grooming. Effects on defecation, urination and vocalization were non-significant. The open-field effects of AM4113 are similar to those reported for rimonabant in rats. Yet, unlike the inverse agonists rimonabant and AM251, the putative neutral CB1R antagonist AM4113 did not produce signs of nausea in ferrets and rats ([Chambers A.P., Vemuri V.K., Peng Y., Wood J.T., Olszewska T., Pittman Q.J., Makriyannis A., Sharkey K.A. A neutral CB1 receptor antagonist reduces weight gain in rat. Am J Physiol Regul Integr Comp Physiol 2007; 293: R2185-2193.; Sink K.S., McLaughlin P.J., Wood J.A., Brown C., Fan P., Vemuri V.K., Pang Y., Olzewska T., Thakur G.A., Makriyannis A., Parker L.A., Salamone J.D. The novel cannabinoid CB(1) receptor neutral antagonist AM4113 suppresses food intake and food-reinforced behavior but does not induce signs of nausea in rats. Neuropsychopharmacology 2008a; 33: 946-955.; Sink K.S., Vemuri V.K., Olszewska T., Makriyannis A., Salamone J.D. Cannabinoid CB1 antagonists and dopamine antagonists produce different effects on a task involving response allocation and effort-related choice in food-seeking behavior. Psychopharmacology (Berl) 2008b; 196: 565-574.]).
Collapse
Affiliation(s)
- T U C Järbe
- Northeastern University, Center for Drug Discovery, 116 Mugar, 360 Huntington Ave., Boston, MA 02115, USA.
| | | | | | | | | | | |
Collapse
|
29
|
Suppression by the cannabinoid CB1 receptor antagonist, rimonabant, of the reinforcing and motivational properties of a chocolate-flavoured beverage in rats. Behav Pharmacol 2008; 19:197-209. [DOI: 10.1097/fbp.0b013e3282fe8888] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
30
|
Abstract
Food, drugs and brain stimulation can serve as strong rewarding stimuli and are all believed to activate common brain circuits that evolved in mammals to favour fitness and survival. For decades, endogenous dopaminergic and opioid systems have been considered the most important systems in mediating brain reward processes. Recent evidence suggests that the endogenous cannabinoid (endocannabinoid) system also has an important role in signalling of rewarding events. First, CB(1) receptors are found in brain areas involved in reward processes, such as the dopaminergic mesolimbic system. Second, activation of CB(1) receptors by plant-derived, synthetic or endogenous CB(1) receptor agonists stimulates dopaminergic neurotransmission, produces rewarding effects and increases rewarding effects of abused drugs and food. Third, pharmacological or genetic blockade of CB(1) receptors prevents activation of dopaminergic neurotransmission by several addictive drugs and reduces rewarding effects of food and these drugs. Fourth, brain levels of the endocannabinoids anandamide and 2-arachidonoylglycerol are altered by activation of reward processes. However, the intrinsic activity of the endocannabinoid system does not appear to play a facilitatory role in brain stimulation reward and some evidence suggests it may even oppose it. The influence of the endocannabinoid system on brain reward processes may depend on the degree of activation of the different brain areas involved and might represent a mechanism for fine-tuning dopaminergic activity. Although involvement of the various components of the endocannabinoid system may differ depending on the type of rewarding event investigated, this system appears to play a major role in modulating reward processes.
Collapse
|
31
|
Sink KS, McLaughlin PJ, Wood JAT, Brown C, Fan P, Vemuri VK, Pang Y, Olzewska T, Thakur GA, Makriyannis A, Parker LA, Salamone JD. The novel cannabinoid CB1 receptor neutral antagonist AM4113 suppresses food intake and food-reinforced behavior but does not induce signs of nausea in rats. Neuropsychopharmacology 2008; 33:946-55. [PMID: 17581535 PMCID: PMC3711240 DOI: 10.1038/sj.npp.1301476] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Drugs that interfere with cannabinoid CB1 transmission suppress various food-motivated behaviors, and it has been suggested that such drugs could be useful as appetite suppressants. Biochemical studies indicate that most of these drugs assessed thus far have been CB1 inverse agonists, and although they have been shown to suppress food intake, they also appear to induce nausea and malaise. The present studies were undertaken to characterize the behavioral effects of AM4113, which is a CB1 neutral antagonist, and to examine whether this drug can reduce food-reinforced behaviors and feeding on diets with varying macronutrient compositions. Biochemical data demonstrated that AM4113 binds to CB1 receptors, but does not show inverse agonist properties (ie no effects on cyclic-AMP production). In tests of spontaneous locomotion and analgesia, AM4113 reversed the effects of the CB1 agonist AM411. AM4113 suppressed food-reinforced operant responding with rats responding on fixed ratio (FR) 1 and 5 schedules of reinforcement in a dose-dependent manner, and also suppressed feeding on high-fat, high-carbohydrate, and lab chow diets. However, in the same dose range that suppressed feeding, AM4113 did not induce conditioned gaping, which is a sign of nausea and food-related malaise in rats. These results suggest that AM4113 may decrease appetite by blocking endogenous cannabinoid tone, and that this drug may be less associated with nausea than CB1 inverse agonists.
Collapse
Affiliation(s)
- Kelly S Sink
- Department of Psychology, University of Connecticut, Storrs, CT, USA
| | | | - Jodi Anne T Wood
- Center for Drug Discovery, Northeastern University, Boston, MA, USA
| | - Cara Brown
- Department of Psychology, University of Connecticut, Storrs, CT, USA
| | - Pusheng Fan
- Center for Drug Discovery, Northeastern University, Boston, MA, USA
| | - V Kiran Vemuri
- Center for Drug Discovery, Northeastern University, Boston, MA, USA
| | - Yan Pang
- Center for Drug Discovery, Northeastern University, Boston, MA, USA
| | - Teresa Olzewska
- Center for Drug Discovery, Northeastern University, Boston, MA, USA
| | - Ganesh A Thakur
- Center for Drug Discovery, Northeastern University, Boston, MA, USA
| | - Alex Makriyannis
- Center for Drug Discovery, Northeastern University, Boston, MA, USA
| | - Linda A Parker
- Department of Psychology, University ofGuelph, Guelph, ON, Canada
| | - John D Salamone
- Department of Psychology, University of Connecticut, Storrs, CT, USA
- Correspondence: Dr JD Salamone, Department of Psychology, University of Connecticut, 406 Babbidge Rd, Storrs, CT 06269-1020, USA, Tel: +1 860 486 4302, Fax: +1 860 486 2760,
| |
Collapse
|
32
|
Tallett AJ, Blundell JE, Rodgers RJ. Grooming, scratching and feeding: role of response competition in acute anorectic response to rimonabant in male rats. Psychopharmacology (Berl) 2007; 195:27-39. [PMID: 17639351 DOI: 10.1007/s00213-007-0880-2] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2007] [Accepted: 06/24/2007] [Indexed: 10/23/2022]
Abstract
RATIONALE Although the CB1 receptor antagonist/inverse agonist rimonabant acutely suppresses food intake in rodents, the behavioural specificity of this effect remains unclear. OBJECTIVES To profile the behavioural effects of rimonabant in a free-feeding context. MATERIALS AND METHODS Videoanalysis was employed to characterise the effects of acute rimonabant (1.5 and 3.0 mg/kg, IP) on the behaviour of non-deprived male rats exposed to palatable mash. Data were also collected on post-treatment weight gain, and, as prolonged appetite suppression has been found after single dosing with compounds of this series, rats were reassessed (drug-free) for food intake 7 days after initial testing. RESULTS Both doses of rimonabant not only decreased mash consumption (44-55%) but also reduced 24-h weight gain. Although videoanalysis confirmed the inhibitory effects of rimonabant on feeding behaviour, it also revealed concurrent reductions in locomotion, rearing and sniffing as well as substantial (up to tenfold) and dose-dependent increases in grooming and scratching. Timecourse analyses further revealed that rimonabant dose-dependently induced frequent episodes of atypical scratching that waned over the test but which were succeeded by prolonged and behaviourally disruptive grooming. Finally, as groups did not differ in mash consumption on retest, any prolonged anorectic effect of acute rimonabant dissipates within 7 days of treatment. CONCLUSIONS The anorectic response to rimonabant in male rats would appear to be due largely to response competition. This parsimonious conclusion is supported by the less profound (although still significant) increases in scratching and grooming observed in rats treated with a sub-anorectic dose (0.5 mg/kg) of the compound.
Collapse
Affiliation(s)
- A J Tallett
- Behavioural Neuroscience Laboratory, Institute of Psychological Sciences, University of Leeds, Leeds, UK
| | | | | |
Collapse
|
33
|
Tallett AJ, Blundell JE, Rodgers JR. Acute anorectic response to cannabinoid CB1 receptor antagonist/inverse agonist AM 251 in rats: indirect behavioural mediation. Behav Pharmacol 2007; 18:591-600. [PMID: 17912043 DOI: 10.1097/fbp.0b013e3282eff0a9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Despite a large and consistent literature on the suppressant effects of cannabinoid CB1 receptor antagonists/inverse agonists (e.g. rimonabant, AM 251) on food intake and weight gain in rodents, surprisingly little is known about the behavioural selectivity of such effects. In this study, ethological scoring was used to characterize the acute behavioural effects of the rimonabant analogue AM 251 (1.5 and 3.0 mg/kg, intraperitoneally) in nondeprived male rats during a 1-h test with palatable mash. Data were also collected on daily weight gain and on retest food intake 7 days after dosing. Results showed that the higher dose of AM 251 significantly inhibited mash consumption (32% decrease relative to vehicle control), reduced time spent feeding during the test and suppressed body weight gain over the 48-h period that followed acute dosing. No effects on mash consumption were observed when the animals were retested drug-free 1 week after drug treatment. Detailed video analysis of the test sessions showed that, over the dose range tested, AM 251 did not significantly interfere with the vast majority of noningestive behaviours. Both doses of the compound, however, significantly increased the incidence of and the time spent on scratching, whereas the higher dose additionally increased both the number and duration of grooming episodes. The latter effect in particular disrupted the normal structure of behaviour (behavioural satiety sequence) with atypically high levels of grooming displacing feeding during the middle part of the test session. Overall, the behavioural profile of AM 251 in a free-feeding context is very similar to (but approximately two-fold less potent than) that recently reported for the parent molecule, rimonabant. Together, these data strongly suggest that the acute anorectic response to CB1 receptor antagonists/inverse agonists is indirectly mediated via major alterations to other components of the behavioural repertoire.
Collapse
Affiliation(s)
- Amy J Tallett
- Behavioural Neuroscience Laboratory, Institute of Psychological Sciences, University of Leeds, Leeds, UK
| | | | | |
Collapse
|
34
|
Cippitelli A, Bilbao A, Gorriti MA, Navarro M, Massi M, Piomelli D, Ciccocioppo R, Rodríguez de Fonseca F. The anandamide transport inhibitor AM404 reduces ethanol self-administration. Eur J Neurosci 2007; 26:476-86. [PMID: 17650118 DOI: 10.1111/j.1460-9568.2007.05665.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The endocannabinoid system mediates in the pharmacological actions of ethanol and genetic studies link endocannabinoid signaling to alcoholism. Drugs activating cannabinoid CB1 receptors have been found to promote alcohol consumption but their effects on self-administration of alcohol are less clear because of the interference with motor performance. To avoid this problem, a novel pharmacological approach to the study of the contribution of the cannabinoid system in alcoholism may be to use drugs that locally amplify the effects of alcohol on endogenous cannabinoids. In the present study we addressed this model by studying the effects of the anandamide transport inhibitor N-(4-hydroxyphenyl) arachidonoyl-ethanolamide (AM404) on both ethanol self-administration and reinstatement of alcohol-seeking behavior in rats. The results show that AM404 significantly reduced ethanol self-administration in a dose-dependent manner but failed to modify reinstatement for lever pressing induced by the stimulus associated with alcohol. This effect was not due to a motor depressant effect and was not related to a decrease in general motivational state, as it was not effective in other reward paradigms such as lever pressing for a saccharin solution. The mechanism of action of AM404 does not involve cannabinoid CB1 receptors as the CB1-selective antagonist SR141716A did not block the reduction of ethanol self-administration induced by the anandamide uptake blocker. Moreover, 3-(1,1-dimethylheptyl)-(-)-11-hydroxy-delta 8-tetrahydrocannabinol (HU-210), a classical cannabinoid receptor agonist, did not affect ethanol self-administration. The effects of AM404 are not mediated by either vanilloid VR1 receptors or cannabinoid CB2 receptors because it is not antagonized by either the VR1 receptor antagonist capsazepine or the CB2 antagonist AM630. These results indicate that AM404 may be considered as an innovative approach to reduce alcohol consumption.
Collapse
MESH Headings
- Alcohol Drinking/psychology
- Animals
- Arachidonic Acids/metabolism
- Arachidonic Acids/pharmacology
- Capsaicin/analogs & derivatives
- Capsaicin/pharmacology
- Central Nervous System Depressants/pharmacology
- Conditioning, Operant/drug effects
- Depression, Chemical
- Endocannabinoids
- Ethanol/pharmacology
- Extinction, Psychological/drug effects
- Hypothermia/chemically induced
- Hypothermia/physiopathology
- Male
- Motor Activity/drug effects
- Polyunsaturated Alkamides/metabolism
- Rats
- Rats, Wistar
- Receptor, Cannabinoid, CB1/agonists
- Receptor, Cannabinoid, CB1/antagonists & inhibitors
- Receptor, Cannabinoid, CB2/antagonists & inhibitors
- Reinforcement, Psychology
- Saccharin/pharmacology
- Self Administration
- TRPV Cation Channels/antagonists & inhibitors
Collapse
Affiliation(s)
- Andrea Cippitelli
- Fundación IMABIS (The European TARGALC Consortium), Hospital Carlos Haya, Avenida Carlos Haya s/n, 7 Planta, Pabellón A, 29010 Málaga, Spain
| | | | | | | | | | | | | | | |
Collapse
|
35
|
Chambers AP, Vemuri VK, Peng Y, Wood JT, Olszewska T, Pittman QJ, Makriyannis A, Sharkey KA. A neutral CB1 receptor antagonist reduces weight gain in rat. Am J Physiol Regul Integr Comp Physiol 2007; 293:R2185-93. [PMID: 17959701 DOI: 10.1152/ajpregu.00663.2007] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Cannabinoid (CB)1 receptor inverse agonists inhibit food intake in animals and humans but also potentiate emesis. It is not clear whether these effects result from inverse agonist properties or from the blockade of endogenous cannabinoid signaling. Here, we examine the effect of a neutral CB1 antagonist, AM4113, on food intake, weight gain, and emesis. Neutral antagonist and binding properties were confirmed in HEK-293 cells transfected with human CB1 or CB2 receptors. AM4113 had no effect on forskolin-stimulated cAMP production at concentrations up to 630 nM. The Ki value of AM4113 (0.80 +/- 0.44 nM) in competitive binding assays with the CB1/2 agonist [3H]CP55,940 was 100-fold more selective for CB1 over CB2 receptors. We determined that AM4113 antagonized CB1 receptors in brain by blocking hypothermia induced by CP55,940. AM4113 (0-20 mg/kg) significantly reduced food intake and weight gain in rat. Compared with AM251, higher doses of AM4113 were needed to produce similar effects on food intake and body weight. Unlike AM251 (5 mg/kg), a highly anorectic dose of AM4113 (10 mg/kg) did not significantly potentiate vomiting induced by the emetic morphine-6-glucoronide. We show that a centrally active neutral CB1 receptor antagonist shares the appetite suppressant and weight loss effects of inverse agonists. If these compounds display similar properties in humans, they could be developed into a new class of antiobesity agents.
Collapse
Affiliation(s)
- Adam P Chambers
- Hotchkiss Brain Institute, Department of Physiology and Biophysics, University of Calgary, Alberta, Canada
| | | | | | | | | | | | | | | |
Collapse
|
36
|
Arias Horcajadas F. Cannabinoids in eating disorders and obesity. Mol Neurobiol 2007; 36:113-28. [PMID: 17952656 DOI: 10.1007/s12035-007-0018-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2006] [Accepted: 03/28/2007] [Indexed: 10/23/2022]
Abstract
Cannabinoid system is a crucial mechanism in regulating food intake and energy metabolism. It is involved in central and peripheral mechanisms regulating such behavior, interacting with many other signaling systems with a role in metabolic regulation. Cannabinoid agonists promote food intake, and soon a cannabinoid antagonist, rimonabant, will be marketed for the treatment of obesity. It not only causes weight loss, but also alleviates metabolic syndrome. We present a review of current knowledge on this subject, along with data from our own research: genetic studies on this system in eating disorders and obesity and studies locating cannabinoid receptors in areas related to food intake. Such studies suggest cannabinoid hyperactivity in obesity, and this excessive activity may have prognostic implications.
Collapse
|
37
|
Thornton-Jones ZD, Kennett GA, Vickers SP, Clifton PG. A comparison of the effects of the CB(1) receptor antagonist SR141716A, pre-feeding and changed palatability on the microstructure of ingestive behaviour. Psychopharmacology (Berl) 2007; 193:1-9. [PMID: 17372721 DOI: 10.1007/s00213-007-0745-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2006] [Accepted: 02/12/2007] [Indexed: 02/05/2023]
Abstract
RATIONALE The cannabinoid CB(1) receptor inverse agonist SR141716A (rimonabant) is known to cause hypophagia and this study uses microstructural data to elucidate the relevant behavioural mechanisms. OBJECTIVES The aim of these studies was to determine the behavioural changes induced by SR141716A in animals consuming either a fat or carbohydrate solution. These behavioural changes were directly compared with those induced by behavioural manipulations that modify motivational state and palatability. METHODS Male hooded Lister rats drank a highly palatable fat emulsion (10% Intralipid) or a carbohydrate solution (10% sucrose) during 30-min test sessions. Microstructural analyses of licking patterns were made after either administration of SR141716A (0, 0.3, 1 and 3 mg/kg, ip) or one of the after behavioural manipulations: pre-feeding, addition of quinine to the fat solution or changes in sucrose concentration. RESULTS Intake of the fat solution was decreased after both the drug treatment and the behavioural manipulations of pre-feeding and addition of quinine. Pre-feeding and SR141716A-induced reductions were mediated via changes in bout number whereas addition of quinine caused a decrease in bout size. Although sucrose drinking was also decreased by pre-feeding, reduced sucrose concentration and SR141716A, the drug did not significantly alter the microstructure of intake. CONCLUSIONS The effects of SR141716A on consumption of Intralipid solutions are likely to reflect changes in motivational state rather than modified hedonic impact.
Collapse
|
38
|
Salamone JD, McLaughlin PJ, Sink K, Makriyannis A, Parker LA. Cannabinoid CB1 receptor inverse agonists and neutral antagonists: effects on food intake, food-reinforced behavior and food aversions. Physiol Behav 2007; 91:383-8. [PMID: 17521686 PMCID: PMC2806672 DOI: 10.1016/j.physbeh.2007.04.013] [Citation(s) in RCA: 107] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Drugs that interfere with cannabinoid CB1 receptor transmission suppress a number of food-related behaviors, and these compounds are currently being assessed for their potential utility as appetite suppressants. In addition to rimonabant (SR141716A), several other compounds have been evaluated, including AM251 and AM1387. Biochemical studies indicate that most of the drugs assessed thus far have been CB1 inverse agonists, and these drugs all act to suppress food intake and disrupt food-reinforced behavior. Behavioral tests involving intake of different diets (i.e., high fat, high carbohydrate, laboratory chow) indicate that consumption of all three food types is disrupted by CB1 inverse agonists, and that, expressed as a percent of baseline intake, the effect is roughly comparable across different diets. Although CB1 inverse agonists do not appear to produce severe motor impairments that disrupt feeding behavior, there is evidence that they can induce nausea and malaise. Recent studies have been undertaken to characterize the behavioral effects of CB1 receptor neutral antagonists such as AM4113 to determine if these drugs can reduce feeding and food-reinforced behaviors. Across a variety of different tests, AM4113 produces effects on food-motivated behavior that are very similar to those produced by CB1 inverse agonists. Moreover, this drug did not induce conditioned gaping in rats or vomiting in ferrets. These results suggest that CB1 receptor neutral antagonists may decrease appetite by blocking endogenous cannabinoid tone, and that these drugs may be less associated with nausea than is the case for CB1 inverse agonists.
Collapse
Affiliation(s)
- John D Salamone
- Department of Psychology, University of Connecticut, 406 Babbidge Road, Storrs, CT 06269-1020, USA.
| | | | | | | | | |
Collapse
|
39
|
Niyuhire F, Varvel SA, Thorpe AJ, Stokes RJ, Wiley JL, Lichtman AH. The disruptive effects of the CB1 receptor antagonist rimonabant on extinction learning in mice are task-specific. Psychopharmacology (Berl) 2007; 191:223-31. [PMID: 17211653 PMCID: PMC2638087 DOI: 10.1007/s00213-006-0650-6] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2006] [Accepted: 11/11/2006] [Indexed: 11/26/2022]
Abstract
RATIONALE Disruption of CB(1) receptor signaling through the use of CB(1) (-/-) mice or the CB(1) receptor antagonist rimonabant (SR141716) has been demonstrated to impair extinction of learned responses in conditioned fear and Morris water maze tasks. In contrast, CB(1) (-/-) mice exhibited normal extinction rates in an appetitively motivated operant conditioning task. OBJECTIVES The purpose of this study was to test whether rimonabant would differentially disrupt extinction learning between fear-motivated and food-motivated tasks. MATERIALS AND METHODS Separate groups of C57BL/6J mice were trained in two aversively motivated tasks, conditioned freezing and passive avoidance, and an appetitively motivated operant conditioning task at a fixed ratio (FR-5) schedule of food reinforcement. After acquisition, the respective reinforcers in each task were withheld, and an intraperitoneal injection of vehicle or rimonabant was given 30 min before each extinction session. RESULTS Rimonabant (3 mg/kg) treatment significantly disrupted extinction in both the conditioned freezing and passive avoidance tasks but failed to affect extinction rates in the operant conditioning task, whether using daily or weekly extinction sessions. Interestingly, rimonabant (3 mg/kg) prevented the significant increases in lever pressing (i.e., extinction burst) that occurred during the first extinction session of the operant conditioning task. CONCLUSIONS These results support the hypothesis that the CB(1) receptor plays a vital role in the extinction of aversive memories but is not essential for extinction of learned responses in appetitively motivated tasks.
Collapse
Affiliation(s)
- Floride Niyuhire
- Department of Pharmacology and Toxicology, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA 23298-0613, USA
| | | | | | | | | | | |
Collapse
|
40
|
Foltin RW, Haney M. Effects of the cannabinoid antagonist SR141716 (rimonabant) and d-amphetamine on palatable food and food pellet intake in non-human primates. Pharmacol Biochem Behav 2007; 86:766-73. [PMID: 17445873 PMCID: PMC1940269 DOI: 10.1016/j.pbb.2007.03.004] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2006] [Revised: 03/05/2007] [Accepted: 03/06/2007] [Indexed: 11/19/2022]
Abstract
The purpose of this study was to determine if a cannabinoid CB(1) receptor antagonist would selectively decrease consumption of highly palatable food in non-human primates. The CB(1) receptor antagonist SR141716 (rimonabant; 0.12-1.0 mg/kg, i.m.) and the stimulant anorectic drug d-amphetamine (0.12-1.0 mg/kg, i.m.) were administered to non-food deprived baboons for the purpose of measuring the effect of each drug on consumption of the normal diet, and a large single meal of a high-carbohydrate candy. Four male and four female baboons had access to food 24 h each day, but they had to complete a two phase operant procedure in order to eat. Responding on one lever during a 30-min appetitive phase was required before animals could start a consumption phase, where responding on another lever led to food delivery, i.e., a meal. Three days a week baboons received a jelly sugar-coated candy (Skittles) during the first meal and then pellets were available in subsequent meals. All baboons ate as many individual candies in one meal as they did pellets throughout the entire day. Acute d-amphetamine and, to a lesser extent, SR141716 decreased both candy intake in a single meal and pellet intake in a single meal and over 24 h. d-Amphetamine, but not SR141716, increased latency to the candy meal and the first pellet meal indicating that the two drugs differentially altered feeding topography. Although males ate more food pellets than females, few other sex differences were observed. Thus, although effective in decreasing food intake, there was no evidence of a specific effect of CB(1) receptor antagonism on consumption of a large meal or a palatable food.
Collapse
Affiliation(s)
- Richard W Foltin
- Division on Substance Abuse, New York State Psychiatric Institute, Department of Psychiatry, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA.
| | | |
Collapse
|
41
|
Chambers AP, Koopmans HS, Pittman QJ, Sharkey KA. AM 251 produces sustained reductions in food intake and body weight that are resistant to tolerance and conditioned taste aversion. Br J Pharmacol 2006; 147:109-16. [PMID: 16258524 PMCID: PMC1615836 DOI: 10.1038/sj.bjp.0706439] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The cannabinoid 1 (CB(1)) receptor has been implicated in the regulation of food intake. Here, we examine the effect of the CB(1) receptor antagonist AM 251 on food intake and body weight over a prolonged period. Further, we examine whether AM 251 produces conditioned taste aversion (CTA) and if sustained antagonism at central receptors contributes to its anorectic effect. The effect of AM 251 of food intake and body weight was examined in daily (1 mg kg(-1)) and 5-day (5 mg kg(-1)) dosing schedules. Matching reductions in food intake and body weight were observed in both paradigms. A single administration of AM 251 (5 mg kg(-1)) significantly reduced food intake for 4 days. Tolerance to the anorectic effects of AM 251 did not develop in either dosing strategy. Active avoidance of AM 251 (3; 5 mg kg(-1), i.p.) was examined using a CTA assay. Rats showed no evidence of CTA associated with AM 251. We investigated the sustained effect of AM 251 (5 mg kg(-1), i.p.) on CB(1) receptors in the hypothalamus using Delta(9)-tetrahydrocannabinol (8 mg kg(-1), i.p.) induced hypothermia. AM 251 initially blocked hypothermia, but this effect was not seen 2 or 4 days later. The results demonstrate that smaller, or infrequent, administrations of AM 251 can produce sustained reductions in food intake and body weight in rat. Reductions in food intake were sustained longer than AM 251 antagonized the effects of a CB(1) receptor agonist in the hypothalamus, and occurred independently of CTA.
Collapse
Affiliation(s)
- Adam P Chambers
- Department of Physiology & Biophysics, Hotchkiss Brain Institute and Institute of Infection, Inflammation and Immunity, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, Canada T2N 4N1
| | - Henry S Koopmans
- Department of Physiology & Biophysics, Hotchkiss Brain Institute and Institute of Infection, Inflammation and Immunity, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, Canada T2N 4N1
| | - Quentin J Pittman
- Department of Physiology & Biophysics, Hotchkiss Brain Institute and Institute of Infection, Inflammation and Immunity, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, Canada T2N 4N1
| | - Keith A Sharkey
- Department of Physiology & Biophysics, Hotchkiss Brain Institute and Institute of Infection, Inflammation and Immunity, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta, Canada T2N 4N1
- Author for correspondence:
| |
Collapse
|
42
|
Jarrett MM, Scantlebury J, Parker LA. Effect of delta9-tetrahydrocannabinol on quinine palatability and AM251 on sucrose and quinine palatability using the taste reactivity test. Physiol Behav 2006; 90:425-30. [PMID: 17118412 DOI: 10.1016/j.physbeh.2006.10.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2006] [Revised: 10/03/2006] [Accepted: 10/10/2006] [Indexed: 10/23/2022]
Abstract
Here we provide evidence that the cannabinoid agonist, Delta9-tetrahydrocannabinol (Delta9-THC) enhances quinine palatability and the CB1 antagonist/inverse agonist, AM251, reduces sucrose and quinine palatability using the taste reactivity test, which provides a direct measure of palatability independently of appetitive behavior. In Experiment 1, rats were treated with a low dose of Delta9-THC (0.5 mg/kg) or Vehicle 30 min, 60 min, 120 min or 240 min prior to a 5-min intraoral infusion of a highly unpalatable 0.05% quinine solution. Regardless of the post-injection interval, Delta9-THC reduced rejection of quinine. The Delta9-THC-induced palatability shift was reversed by AM251. In Experiment 2, rats were injected with either AM251 (1 mg/kg) or Vehicle prior to receiving a 5-min intraoral infusion of either 32% sucrose or 0.05% quinine solution. AM251 significantly decreased sucrose-elicited hedonic reactions across both time intervals; however, AM251 did not significantly modify the rejection of 0.05% quinine solution. When the concentration of the quinine solution was reduced to 0.01% in Experiment 3, AM251 enhanced quinine aversion. Although the range of concentrations of the solutions tested in the present data is limited, our results suggest that the cannabinoid system may modulate the palatability of ingested substances regardless of the palatability of the ingested substance.
Collapse
Affiliation(s)
- Maegan M Jarrett
- Department of Psychology Wilfrid Laurier University Waterloo, Ontario, Canada N2L 3C5
| | | | | |
Collapse
|
43
|
Carai MAM, Colombo G, Maccioni P, Gessa GL. Efficacy of rimonabant and other cannabinoid CB1 receptor antagonists in reducing food intake and body weight: preclinical and clinical data. CNS DRUG REVIEWS 2006; 12:91-9. [PMID: 16958983 PMCID: PMC6494144 DOI: 10.1111/j.1527-3458.2006.00091.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The present paper focuses on the different lines of evidence indicating that cannabinoid CB(1) receptor antagonists, including the prototype rimonabant, reduce food intake and body weight in laboratory animals. Recent clinical surveys demonstrated that rimonabant significantly reduced body weight also in overweight/obese humans. Treatment with rimonabant was associated with a beneficial effect on different metabolic parameters and cardiovascular risk factors linked to overweight. The data reviewed in this paper suggest that cannabinoid CB(1) receptor antagonists may constitute a novel class of drugs potentially effective in the treatment of obesity-related disorders.
Collapse
Affiliation(s)
- Mauro A M Carai
- C.N.R. Institute of Neuroscience, University of Cagliari, Cagliari (CA), Italy.
| | | | | | | |
Collapse
|
44
|
Matias I, Bisogno T, Di Marzo V. Endogenous cannabinoids in the brain and peripheral tissues: regulation of their levels and control of food intake. Int J Obes (Lond) 2006; 30 Suppl 1:S7-S12. [PMID: 16570107 DOI: 10.1038/sj.ijo.0803271] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Endocannabinoids were first defined in 1995 as 'endogenous substances capable of binding to and functionally activating the cannabinoid receptors'. To date, two well-established endocannabinoids, N-arachidonoylethanolamine (anandamide) and 2-arachidonoylglycerol (2-AG), as well as a few other putative ligands, all derived from long-chain polyunsaturated fatty acids, have been identified in animal tissues. The biosynthetic and metabolic pathways for anandamide and 2-AG have been elucidated, and most of the enzymes therein involved have been cloned. We now know that CB1 receptors, and endocannabinoids in tissue concentrations sufficient to activate them, are more widely distributed than originally thought, and are found in brain and peripheral organs involved in the control of energy intake and processing, including the hypothalamus, nucleus accumbens, brainstem, vagus nerve, gastrointestinal tract, adipose tissue and liver. Endocannabinoid biosynthetic and inactivating pathways are under the regulation of neuropeptides and hormones involved in energy homeostasis, and endocannabinoid levels are directly affected by the diet. Endocannabinoids, in turn, regulate the expression and action of mediators involved in nutrient intake and processing. These cross-talks are at the basis of the proposed role of endocannabinoid signalling in the control of food intake, from invertebrates to lower vertebrates and mammals, and their perturbation appears to contribute to the development of eating disorders.
Collapse
Affiliation(s)
- I Matias
- Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche, Pozzuoli (NA), Italy
| | | | | |
Collapse
|
45
|
Thornton-Jones ZD, Kennett GA, Benwell KR, Revell DF, Misra A, Sellwood DM, Vickers SP, Clifton PG. The cannabinoid CB1 receptor inverse agonist, rimonabant, modifies body weight and adiponectin function in diet-induced obese rats as a consequence of reduced food intake. Pharmacol Biochem Behav 2006; 84:353-9. [PMID: 16814374 DOI: 10.1016/j.pbb.2006.06.001] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2006] [Revised: 05/09/2006] [Accepted: 06/01/2006] [Indexed: 11/26/2022]
Abstract
The cannabinoid CB1 receptor inverse agonist rimonabant induces hypophagia and body weight loss. Reduced body weight may potentially be due to decreased food intake or to direct metabolic effects of drug administration on energy expenditure. This study uses a paired-feeding protocol to quantify the contributions of energy intake to rimonabant-induced body weight loss. Diet-induced obese (DIO) rats were dosed with rimonabant (3, 10 mg/kg PO once daily) and matched with pair-fed controls. Food intake and body weight were measured daily. Blood samples and adipose tissue were collected on day 15 for measurement of plasma adiponectin and adiponectin mRNA levels. DIO rats treated with rimonabant and pair-fed controls showed very similar changes in body weight. Although tolerance developed to the anorectic effect of rimonabant, total food intake was significantly decreased over the 14-day study period and fully accounted for the observed reductions in body weight. Adiponectin mRNA and plasma adiponectin were elevated in vehicle-treated chow-fed animals compared to obese controls, and did not differ between rimonabant-treated and pair-fed animals. The similarities between rimonabant-treated and pair-fed animals in body weight loss and the absence of differences in measures of adiponectin activity between drug-treated and pair-fed animals suggest that the outcomes of this experiment were solely mediated by the drug-induced reduction in food intake.
Collapse
Affiliation(s)
- Zoë D Thornton-Jones
- Department of Psychology, John Maynard Smith Building, University of Sussex, Brighton, BN1 9QG, UK
| | | | | | | | | | | | | | | |
Collapse
|
46
|
Jobst EE, Enriori PJ, Sinnayah P, Cowley MA. Hypothalamic regulatory pathways and potential obesity treatment targets. Endocrine 2006; 29:33-48. [PMID: 16622291 DOI: 10.1385/endo:29:1:33] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/08/2005] [Revised: 11/30/1999] [Accepted: 11/08/2005] [Indexed: 12/25/2022]
Abstract
With an ever-growing population of obese people as well as comorbidities associated with obesity, finding effective weight loss strategies is more imperative than ever. One of the challenges in curbing the obesity crisis is designing successful strategies for long-term weight loss and weight-loss maintenance. Currently, weight-loss strategies include promotion of therapeutic lifestyle changes (diet and exercise), pharmacological therapy, and bariatric surgery. This review focuses on several pharmacological targets that activate central nervous system pathways that normally limit food intake and body weight. Though it is likely that no single therapy will prove effective for everyone, this review considers several recent pre-clinical targets, and several compounds that have been in human clinical trials.
Collapse
Affiliation(s)
- Erin E Jobst
- Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA.
| | | | | | | |
Collapse
|
47
|
Wiley JL, Burston JJ, Leggett DC, Alekseeva OO, Razdan RK, Mahadevan A, Martin BR. CB1 cannabinoid receptor-mediated modulation of food intake in mice. Br J Pharmacol 2006; 145:293-300. [PMID: 15778743 PMCID: PMC1576140 DOI: 10.1038/sj.bjp.0706157] [Citation(s) in RCA: 145] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
1 Marijuana's appetite-increasing effects have long been known. Recent research suggests that the CB(1) cannabinoid receptor antagonist SR141716A may suppress appetite. This study represents a further, systematic investigation of the role of CB(1) cannabinoid receptors in the pharmacological effects of cannabinoids on food intake. 2 Mice were food-restricted for 24 h and then allowed access to their regular rodent chow for 1 h. Whereas the CB(1) antagonist SR141716A dose-dependently decreased food consumption at doses that did not affect motor activity, Delta(9)-tetrahydrocannabinol (Delta(9)-THC) increased food consumption at doses that had no effect on motor activity. O-3259 and O-3257, structural analogs of SR141716A, produced effects similar to those of the parent compound. 3 Amphetamine (a known anorectic) and diazepam (a benzodiazepine and CNS depressant) decreased food consumption, but only at doses that also increased or decreased motor activity, respectively. The CB(2) cannabinoid receptor antagonist SR144528 and the nonpsychoactive cannabinoid cannabidiol did not affect food intake nor activity. 4 SR141716A decreased feeding in wild-type mice, but lacked pharmacological activity in CB(1) knockout mice; however, basal food intake was lower in CB(1) knockout mice. Amphetamine decreased feeding in both mouse genotypes. 5 These results suggest that SR141716A may affect the actions of endogenous cannabinoids in regulating appetite or that it may have effects of its own aside from antagonism of cannabinoid effects (e.g., decreased feeding behavior and locomotor stimulation). In either case, these results strongly suggest that CB(1) receptors may play a role in regulation of feeding behavior.
Collapse
MESH Headings
- Animals
- Dose-Response Relationship, Drug
- Dronabinol/chemistry
- Dronabinol/pharmacology
- Eating/drug effects
- Eating/physiology
- Female
- Male
- Mice
- Mice, Inbred ICR
- Mice, Knockout
- Piperidines/chemistry
- Piperidines/pharmacology
- Pyrazoles/chemistry
- Pyrazoles/pharmacology
- Receptor, Cannabinoid, CB1/agonists
- Receptor, Cannabinoid, CB1/antagonists & inhibitors
- Receptor, Cannabinoid, CB1/deficiency
- Receptor, Cannabinoid, CB1/physiology
- Rimonabant
Collapse
Affiliation(s)
- Jenny L Wiley
- Department of Pharmacology and Toxicology, Virginia Commonwealth University, Box 980613, Richmond, VA 23298-0613, USA.
| | | | | | | | | | | | | |
Collapse
|
48
|
McMahon LR, Amin MR, France CP. SR 141716A differentially attenuates the behavioral effects of delta9-THC in rhesus monkeys. Behav Pharmacol 2006; 16:363-72. [PMID: 16148440 DOI: 10.1097/00008877-200509000-00008] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The prototypic cannabinoid CB1 antagonist SR 141716A is one important pharmacologic tool for examining CB1 receptors that mediate the behavioral and physiologic effects of delta9-tetrahydrocannabinol (delta9-THC). This study examined the effects of SR 141716A on the rate-decreasing, hypothermic and discriminative stimulus effects of delta9-THC in rhesus monkeys. In monkeys (n=4) responding under a multiple fixed ratio (FR-10:FR-10) schedule of food presentation and stimulus-shock termination, the potency of i.m. delta9-THC to decrease responding in the food component (ED50=0.64 mg/kg) was threefold greater than its potency in the stimulus-shock termination component (ED50=2.14 mg/kg). In the same monkeys, hypothermia was induced by delta9-THC at a dose (e.g. 0.32 mg/kg) that did not alter responding in either schedule component; the maximum decrease was 2.1 degrees C at a dose of 3.2 mg/kg. A dose of 0.32 mg/kg of SR 141716A, significantly attenuated delta9-THC-induced hypothermia without attenuating the rate-decreasing effects of delta9-THC in either component of the multiple schedule. The largest dose of i.m. SR 141716A that was studied, 1.0 mg/kg, significantly decreased rectal temperature and responding in the food component but did not significantly decrease responding in the stimulus-shock termination component of the multiple schedule. In a separate group of monkeys (n=3) that discriminated i.v. delta9-THC (0.1 mg/kg) while responding under an FR-5 schedule of stimulus-shock termination, SR 141716A (0.32 and 1 mg/kg) significantly increased the ED50 of the delta9-THC by 2.3- and 3.7-fold, respectively. Collectively, these results demonstrate that the behavioral effects of delta9-THC are not equally attenuated by SR 141716A.
Collapse
MESH Headings
- Animals
- Behavior, Animal/drug effects
- Behavior, Animal/physiology
- Body Temperature/drug effects
- Discrimination, Psychological/drug effects
- Dose-Response Relationship, Drug
- Dronabinol/pharmacology
- Female
- Macaca mulatta
- Male
- Piperidines/pharmacology
- Pyrazoles/pharmacology
- Receptor, Cannabinoid, CB1/agonists
- Receptor, Cannabinoid, CB1/antagonists & inhibitors
- Receptor, Cannabinoid, CB1/physiology
- Rimonabant
- Time Factors
Collapse
Affiliation(s)
- L R McMahon
- Department of Pharmacology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229-3900, USA.
| | | | | |
Collapse
|
49
|
Economidou D, Mattioli L, Cifani C, Perfumi M, Massi M, Cuomo V, Trabace L, Ciccocioppo R. Effect of the cannabinoid CB1 receptor antagonist SR-141716A on ethanol self-administration and ethanol-seeking behaviour in rats. Psychopharmacology (Berl) 2006; 183:394-403. [PMID: 16261315 DOI: 10.1007/s00213-005-0199-9] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2004] [Accepted: 09/05/2005] [Indexed: 11/25/2022]
Abstract
RATIONALE It has been suggested that endocannabinoid mechanisms are involved in the control of ethanol consumption. OBJECTIVES The aims of the present study were (1) to evaluate the role of the endocannabinoid system in the control of operant ethanol self-administration and in the reinstatement of ethanol seeking, when induced by stress or conditioned stimuli and (2) to offer new insights on the specificity of such a role. METHODS Rats were administered intraperitoneally with the selective cannabinoid CB1 receptor antagonist, SR-141716A, 30 min before operant self-administration or reinstatement sessions. Two schedules of reinforcement, the fixed-ratio 1 (FR1) and the progressive ratio (PR), were used to study 10% (w/v) alcohol and 5.0% sucrose self-administration. NaCl (2% w/v) intake in sodium-depleted rats was studied only under the FR1 program. RESULTS Treatment with SR-141716A (0.3-3.0 mg/kg) significantly attenuated FR1 alcohol self-administration and lowered the break point for ethanol under PR. SR-141716A also markedly inhibited the reinstatement of alcohol seeking elicited by presentation of cues predictive of drug availability. Conversely, the cannabinoid antagonist did not prevent the reinstatement of alcohol seeking induced by foot-shock stress. Lever pressing for sucrose under FR1 and PR schedules was also significantly decreased by SR-141716A treatment, whereas the drug modestly and only at the highest dose decreased 2% NaCl self-administration. CONCLUSIONS Results emphasize that endocannabinoid mechanisms play a major role in the control of ethanol self-administration and in the reinstatement of conditioned ethanol seeking. However, these effects extend to the control of operant behaviours motivated by natural rewards (i.e. sucrose). On the other hand, SR-141716A only weakly reduces NaCl self-administration in sodium-depleted rats, in which salt intake is largely controlled by homeostatic mechanisms. Overall, these observations demonstrate that the inhibition of operant behaviour following blockade of CB1 receptors by SR-141716A is linked to a reduction of reward-related responding and is not related to drug-induced motor deficits.
Collapse
Affiliation(s)
- Daina Economidou
- Department of Experimental Medicine and Public Health, University of Camerino, Via Scalzino 3, 62032, Camerino, Italy
| | | | | | | | | | | | | | | |
Collapse
|
50
|
Witkin JM, Tzavara ET, Davis RJ, Li X, Nomikos GG. A therapeutic role for cannabinoid CB1 receptor antagonists in major depressive disorders. Trends Pharmacol Sci 2005; 26:609-17. [PMID: 16260047 DOI: 10.1016/j.tips.2005.10.006] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2005] [Revised: 09/15/2005] [Accepted: 10/11/2005] [Indexed: 11/30/2022]
Abstract
Cannabinoid receptors in the CNS have been implicated in the control of appetite, cognition, mood and drug dependence. Recent findings support the hypothesis that cannabinoid CB1 receptor blockade might be associated with antidepressant and anti-stress effects. A novel potential antidepressant drug class based on this mechanism is supported by the neuroanatomical localization of CB1 receptors and signal transduction pathways that are involved in emotional responses, together with the antidepressant-like neurochemical and behavioral effects induced by CB1 receptor antagonists. Selective CB1 receptor antagonists are in development for the treatment of obesity and tobacco smoking, and could be tested for antidepressant efficacy because recent results of clinical studies suggest that they would also treat comorbid symptoms of depression such as cognitive deficiencies, weight gain, impulsivity and dependence disorders. Thus, CB1 receptor antagonism might constitute an integrated pharmacotherapeutic approach that impacts the affective, cognitive, appetitive and motivational neuronal networks involved in mood disorders.
Collapse
Affiliation(s)
- Jeffrey M Witkin
- Psychiatric Drug Discovery, Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285-0510, USA.
| | | | | | | | | |
Collapse
|