sr-144528 and Pain

sr-144528 has been researched along with Pain* in 24 studies

Reviews

1 review(s) available for sr-144528 and Pain

ArticleYear
Cannabinoids and pain.
    Current opinion in investigational drugs (London, England : 2000), 2001, Volume: 2, Issue:3

    Recent advances have dramatically increased our understanding of cannabinoid pharmacology: the psychoactive constituents of Cannabis sativa have been isolated, synthetic cannabinoids described and an endocannabinoid system identified, together with its component receptors, ligands and their biochemistry. Strong laboratory evidence now underwrites anecdotal claims of cannabinoid analgesia in inflammatory and neuropathic pain. Sites of analgesic action have been identified in brain, spinal cord and the periphery, with the latter two presenting attractive targets for divorcing the analgesic and psychotrophic effects of cannabinoids. Clinical trials are now required, but are hindered by a paucity of cannabinoids of suitable bioavailability and therapeutic ratio.

    Topics: Amides; Amidohydrolases; Analgesics; Animals; Arachidonic Acids; Benzoxazines; Brain; Camphanes; Cannabinoid Receptor Modulators; Cannabinoids; Cell Membrane; Clinical Trials as Topic; Disease Models, Animal; Drug Design; Drug Interactions; Endocannabinoids; Enzyme Inhibitors; Ethanolamines; Glycerides; Humans; Injections, Spinal; Molecular Structure; Morpholines; Naphthalenes; Pain; Palmitates; Palmitic Acids; Piperidines; Plant Extracts; Polyunsaturated Alkamides; Pyrazoles; Receptors, Cannabinoid; Receptors, Drug; Rimonabant; Spinal Cord

2001

Other Studies

23 other study(ies) available for sr-144528 and Pain

ArticleYear
Antinociceptive effects of JWH015 in female and male rats.
    Behavioural pharmacology, 2018, Volume: 29, Issue:2 and 3-Sp

    Despite greater chronic pain prevalence in females compared with males, and the analgesic potential of cannabinoid receptor type 2 (CB2) agonists, CB2 agonists have rarely been tested in females. The aim of the present study was to compare the antinociceptive effects of a CB2-preferring agonist, (2-methyl-1-propyl-1H-indol-3-yl)-1-naphthalenylmethanone (JWH015), in female and male rats against acute pain and persistent inflammatory pain. JWH015 (5-20 mg/kg, intraperitoneally) produced dose-dependent and time-dependent increases in latency to respond on the tail withdrawal and paw pressure tests that did not differ statistically between the sexes. JWH015 dose-dependently decreased locomotor activity in both sexes, but was more potent in females than males. JWH015 produced little catalepsy in either sex. In females, the antinociceptive effects of JWH015 against acute pain were blocked by rimonabant and SR144528, whereas locomotor suppression was antagonized by rimonabant. When administered 3 days after intraplantar injection of complete Freund's adjuvant, JWH015 produced a significantly greater antiallodynic effect in females at the highest dose tested (10 mg/kg, intraperitoneally). Antiallodynic effects of JWH015 were antagonized by rimonabant and SR144528 in both sexes. These studies indicate that systemically administered JWH015 produced antinociception that was both CB1 and CB2 receptor-mediated in both sexes. Unlike [INCREMENT]-9-tetrahydrocannabinol and other nonselective cannabinoid agonists, the CB2-preferring agonist JWH015 may produce more equivalent antinociception in females and males.

    Topics: Analgesics; Animals; Camphanes; Cannabinoid Receptor Agonists; Dronabinol; Female; Freund's Adjuvant; Indoles; Male; Pain; Pain Measurement; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Rimonabant; Sex Factors

2018
Antinociceptive effect of the cannabinoid agonist, WIN 55,212-2, in the orofacial and temporomandibular formalin tests.
    European journal of pain (London, England), 2010, Volume: 14, Issue:1

    Orofacial pain disorders are frequent in the general population and their pharmacological treatment is not always adequately resolved. Cannabinoids have demonstrated their analgesic effect in several pain conditions, both in animal models and in clinical situations. The aim of the present study was to evaluate the cannabinoid-mediated antinociception in two inflammatory models of orofacial pain (orofacial and temporomandibular joint (TMJ) formalin test) and to compare it with a spinal inflammatory model (paw formalin test). WIN 55,212-2 (0.5, 1mg/kg), a synthetic cannabinoid agonist, was intraperitoneally (i.p.) administered prior to formalin and significantly reduced the nociceptive behavioural responses in these inflammatory tests. To elucidate which subtype of receptor could be involved in such effect, two selective cannabinoid antagonists were administered prior to WIN. SR141716A (1mg/kg i.p.), the CB1 receptor-selective antagonist, was able to prevent the cannabinoid-induced analgesia in all three models, whereas SR144528 (1mg/kg i.p.), the CB2 receptor-selective antagonist, only prevented it in the paw formalin test. A comparison with the antinociceptive effects of morphine (2.5, 5, 10mg/kg, i.p.), indomethacin (2.5, 5mg/kg, i.p.) and ketamine (25, 50mg/kg, i.p.) was also performed. Morphine displayed a dose-dependent reduction of acute and inflammatory pain in all three models, whereas indomethacin and ketamine only attenuated inflammatory pain at the highest tested doses. These results indicate that the cannabinoid-induced antinociception in the orofacial region is mediated by activation of CB1 cannabinoid receptor. Moreover WIN was as effective as morphine and more effective than indomethacin and ketamine, in oral inflammatory pain.

    Topics: Analgesics; Analgesics, Opioid; Anesthetics, Dissociative; Animals; Anti-Inflammatory Agents, Non-Steroidal; Behavior, Animal; Benzoxazines; Camphanes; Facial Pain; Formaldehyde; Indomethacin; Inflammation; Ketamine; Male; Morphine; Morpholines; Motor Activity; Naphthalenes; Pain; Piperidines; Pyrazoles; Rats; Rats, Wistar; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Rimonabant; Temporomandibular Joint Disorders

2010
Spinal and peripheral analgesic effects of the CB2 cannabinoid receptor agonist AM1241 in two models of bone cancer-induced pain.
    British journal of pharmacology, 2010, Volume: 160, Issue:3

    The activation of CB(2) receptors induces analgesia in experimental models of chronic pain. The present experiments were designed to study whether the activation of peripheral or spinal CB(2) receptors relieves thermal hyperalgesia and mechanical allodynia in two models of bone cancer pain.. NCTC 2472 osteosarcoma or B16-F10 melanoma cells were intratibially inoculated to C3H/He and C57BL/6 mice. Thermal hyperalgesia was assessed by the unilateral hot plate test and mechanical allodynia by the von Frey test. AM1241 (CB(2) receptor agonist), AM251 (CB(1) receptor antagonist), SR144528 (CB(2) receptor antagonist) and naloxone were used. CB(2) receptor expression was measured by Western blot.. AM1241 (0.3-10 mg.kg(-1)) abolished thermal hyperalgesia and mechanical allodynia in both tumour models. The antihyperalgesic effect was antagonized by subcutaneous, intrathecal or peri-tumour administration of SR144528. In contrast, the antiallodynic effect was inhibited by systemic or intrathecal, but not peri-tumour, injection of SR144528. The effects of AM1241 were unchanged by AM251 but were prevented by naloxone. No change in CB(2) receptor expression was found in spinal cord or dorsal root ganglia.. Spinal CB(2) receptors are involved in the antiallodynic effect induced by AM1241 in two neoplastic models while peripheral and spinal receptors participate in the antihyperalgesic effects. Both effects were mediated by endogenous opiates. The use of drugs that activate CB(2) receptors could be a useful strategy to counteract bone cancer-induced pain symptoms.

    Topics: Analgesics; Animals; Bone Neoplasms; Camphanes; Cannabinoids; Cell Line, Tumor; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Interactions; Ganglia, Spinal; Humans; Mice; Mice, Inbred C3H; Mice, Inbred C57BL; Naloxone; Osteosarcoma; Pain; Pain Measurement; Piperidines; Pyrazoles; Receptor, Cannabinoid, CB2; Spinal Cord

2010
The endocannabinoid transport inhibitor AM404 modulates nociception in cholestasis.
    Neuroscience letters, 2009, Oct-25, Volume: 462, Issue:3

    Cholestasis is associated with increased activity of the endogenous opioid system that results in analgesia. Endocannabinoid system can reduce pain sensitivity. Considering the interaction that has been shown between the endogenous opioid and endocannabinoid systems in nociception processing, we studied the effect of AM404, an endocannabinoid transport inhibitor, on modulation of nociception in cholestasis, a model of elevated endogenous opioid tone. Cholestasis was induced by ligation of the main bile duct using two ligatures and transection of the duct at the midpoint between them. A significant increase (P<0.01) in TF was observed in cholestatic rats compared to unoperated and sham rats. AM404 (10 mg/kg, i.p.) significantly increased TFL at 5, 30 min but not 60 min after injection in cholestatic animals compared to the vehicle treated cholestatic group (P<0.05, P<0.001, respectively). AM404 injection to unoperated and sham rats did not alter baseline TFL. The effect of AM404 in cholestatic rats was blocked by co-administration of a CB(1) receptor antagonist, AM251 (1 mg/kg, i.p.) but not by the CB2 receptor antagonist, SR144528 (1 mg/kg, i.p.). Naloxone injection blocked the antinociception induced by cholestasis in bile duct ligated group. Antinociception produced by injection of AM404 in cholestatics was also attenuated by co-administration of naloxone. These data show that AM404 potentiates antinociception induced by cholestasis and indicate that there are possible interactions between opioid and cannabinoid systems in this experimental model of elevated endogenous opioid tone. The inhibitory effects of AM404 in this model are mediated by cannabinoid CB(1) and not CB(2) receptors.

    Topics: Animals; Arachidonic Acids; Biological Transport; Camphanes; Cannabinoid Receptor Modulators; Cholestasis; Endocannabinoids; Male; Naloxone; Opioid Peptides; Pain; Piperidines; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2

2009
Evaluation of prevalent phytocannabinoids in the acetic acid model of visceral nociception.
    Drug and alcohol dependence, 2009, Nov-01, Volume: 105, Issue:1-2

    Considerable preclinical research has demonstrated the efficacy of Delta(9)-tetrahydrocannabinol (Delta(9)-THC), the primary psychoactive constituent of Cannabis sativa, in a wide variety of animal models of pain, but few studies have examined other phytocannabinoids. Indeed, other plant-derived cannabinoids, including cannabidiol (CBD), cannabinol (CBN), and cannabichromene (CBC) elicit antinociceptive effects in some assays. In contrast, tetrahydrocannabivarin (THCV), another component of cannabis, antagonizes the pharmacological effects of Delta(9)-THC. These results suggest that various constituents of this plant may interact in a complex manner to modulate pain. The primary purpose of the present study was to assess the antinociceptive effects of these other prevalent phytocannabinoids in the acetic acid stretching test, a rodent visceral pain model. Of the cannabinoid compounds tested, Delta(9)-THC and CBN bound to the CB(1) receptor and produced antinociceptive effects. The CB(1) receptor antagonist, rimonabant, but not the CB(2) receptor antagonist, SR144528, blocked the antinociceptive effects of both compounds. Although THCV bound to the CB(1) receptor with similar affinity as Delta(9)-THC, it had no effects when administered alone, but antagonized the antinociceptive effects of Delta(9)-THC when both drugs were given in combination. Importantly, the antinociceptive effects of Delta(9)-THC and CBN occurred at lower doses than those necessary to produce locomotor suppression, suggesting motor dysfunction did not account for the decreases in acetic acid-induced abdominal stretching. These data raise the intriguing possibility that other constituents of cannabis can be used to modify the pharmacological effects of Delta(9)-THC by either eliciting antinociceptive effects (i.e., CBN) or antagonizing (i.e., THCV) the actions of Delta(9)-THC.

    Topics: Acetic Acid; Analgesics; Animals; Anti-Obesity Agents; Camphanes; Cannabinoids; Cyclohexanols; Dose-Response Relationship, Drug; Dronabinol; Male; Mice; Mice, Inbred ICR; Motor Activity; Pain; Pain Measurement; Piperidines; Pyrazoles; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Rimonabant; RNA, Messenger

2009
CB(2) cannabinoid receptor antagonist SR144528 decreases mu-opioid receptor expression and activation in mouse brainstem: role of CB(2) receptor in pain.
    Neurochemistry international, 2008, Volume: 53, Issue:6-8

    Formerly considered as an exclusively peripheral receptor, it is now accepted that CB(2) cannabinoid receptor is also present in limited amounts and distinct locations in the brain of several animal species, including mice. However, the possible roles of CB(2) receptors in the brain need to be clarified. The aim of our work was to study the mu-opioid receptor (MOR) mRNA expression level and functional activity after acute in vivo and in vitro treatments with the endocannabinoid noladin ether (NE) and with the CB(2) receptor antagonist SR144528 in brainstem of mice deficient in either CB(1) or CB(2) receptors. This study is based on our previous observations that noladin ether (NE) produces decrease in the activity of MOR in forebrain and this attenuation can be antagonized by the CB(2) cannabinoid antagonist SR144528, suggesting a CB(2) receptor mediated effect. We used quantitative real-time PCR to examine the changes of MOR mRNA levels, [(35)S]GTPgammaS binding assay to analyze the capability of mu-opioid agonist DAMGO to activate G-proteins and competition binding assays to directly measure the ligand binding to MOR in mice brainstem. After acute NE administration no significant changes were observed on MOR signaling. Nevertheless pretreatment of mice with SR144528 prior to the administration of NE significantly decreased MOR signaling suggesting the involvement of SR144528 in mediating the effect of MOR. mRNA expression of MORs significantly decreased both in CB(1) wild-type and CB(1) knockout mice after a single injection of SR144528 at 0.1mg/kg when compared to the vehicle treated controls. Consequently, MOR-mediated signaling was attenuated after acute in vivo treatment with SR144528 in both CB(1) wild-type and CB(1) knockout mice. In vitro addition of 1microM SR144528 caused a decrease in the maximal stimulation of DAMGO in [(35)S]GTPgammaS binding assays in CB(2) wild-type brainstem membranes whereas no significant changes were observed in CB(2) receptor knockouts. Radioligand binding competition studies showed that the noticed effect of SR144528 on MOR signaling is not mediated through MORs. Our data demonstrate that the SR144528 caused pronounced decrease in the activity of MOR is mediated via CB(2) cannabinoid receptors.

    Topics: Animals; Binding, Competitive; Brain Stem; Camphanes; Cannabinoid Receptor Modulators; Down-Regulation; Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; Glycerides; Mice; Mice, Inbred C57BL; Mice, Knockout; Nociceptors; Pain; Pyrazoles; Radioligand Assay; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Receptors, Opioid, mu; RNA, Messenger

2008
Pharmacological evaluation of a novel cannabinoid 2 (CB2) ligand, PF-03550096, in vitro and in vivo by using a rat model of visceral hypersensitivity.
    Journal of pharmacological sciences, 2008, Volume: 106, Issue:2

    Previous studies have shown that cannabinoid 2 (CB(2))-receptor agonists might have analgesic effects on visceral hypersensitivity. To extend these results, we have determined the pharmacological characteristics of a newly designed CB(2) ligand, N-[(1S)-1-(aminocarbonyl)-2,2-dimethylpropyl]-3-(3-hydroxy-3-methylbutyl)-2-oxo-2,3-dihydro-1H-benzimidazole-1-carboxamide (PF-03550096), in vitro and in vivo. PF-03550096 showed high affinity to human (K(i) = 7.9 +/- 1.7 nM) and rat CB(2) receptors (K(i) = 47 +/- 5.6 nM). In a cell-based functional assay, PF-03550096 behaved as a full agonist and showed high selectivity for human CB(2) receptors. Orally administered PF-03550096 (3, 10 mg/kg) inhibited the 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced decrease in colonic pain threshold with statistical significance. The inhibitory effect of PF-03550096 (10 mg/kg) was significantly reversed by a selective CB(2) antagonist, N-(1S)-endo-1,3,3-trimethylbicyclo[2.2.1]heptan-2-yl-5-(4-chloro-3-methylphenyl)-1(4-methylbenzyl)-pyrazole-3-carboxamide (SR144528), while SR144528 itself did not modify colonic pain threshold. These results indicate that PF-03550096 is a potent CB(2) agonist and possesses efficacy in a rat model of visceral hypersensitivity.

    Topics: Animals; Benzimidazoles; Camphanes; Cell Line; CHO Cells; Cricetinae; Cricetulus; Cyclic AMP; Humans; Irritable Bowel Syndrome; Male; Pain; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Trinitrobenzenesulfonic Acid

2008
First in vivo evidence for a functional interaction between chemokine and cannabinoid systems in the brain.
    The Journal of pharmacology and experimental therapeutics, 2008, Volume: 325, Issue:2

    Growing evidence supports the idea that in addition to their well established role in the immune system, chemokines might play a role in both normal and pathological brain function, and the chemokine network could interact with other neuromodulators. The chemokine stromal cell-derived growth factor (SDF)-1alpha/CXCL12, a member of the CXC chemokine family, was tested for its possible effect on the analgesic responses of the cannabinoid receptor agonist aminoalkylindole 4,5-dihydro-2-methyl-4-(4-morpholinylmethyl)-1-(1-naphthalenyl-carbonyl)-6H-pyrrolo-[3,2,1ij]quinolin-6-one [(+)-WIN 55,212-2, hereafter WIN 55,212-2] at the level of the periaqueductal gray (PAG), a brain region critical to the processing of pain signals, and a primary site of action of many analgesic compounds. The administration of WIN 55,212-2 (0.1-0.4 microg/microl) into the PAG resulted in antinociception in a dose-dependent manner. The selective cannabinoid (CB)1 antagonist N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide hydrochloride (SR 141716A; 1-10 microg) given into the PAG blocked the WIN 55,212-2-induced antinociception. In contrast, the selective CB2 antagonist N-[(1S)-endo-1,3,3-trimethyl bicyclo heptan-2-yl]-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-pyrazole-3-carboxamide (SR144528; 10 microg) did not alter the WIN 55,212-2-induced antinociception. Pretreatment with SDF-1alpha/CXCL12 (100 ng) caused a reduction in antinociceptive responses of WIN 55,212-2. The inhibitory effect of SDF-1alpha/CXCL12 on WIN 55,212-2-induced antinociception was reversed by octahydrochloride [corrected] hydrate (AMD 3100) (10-50 ng), an antagonist of the SDF-1alpha/CXCL12, acting at its receptor, CXCR4. This study reports the first in vivo evidence of a functional interaction between chemokine and cannabinoid systems in the brain, showing that the activation of SDF-1alpha/CXCL12 receptors (CXCR4) in the PAG interferes with the analgesic effects of WIN 55212-2.

    Topics: Analgesics; Animals; Benzoxazines; Camphanes; Chemokine CXCL12; Male; Morpholines; Naphthalenes; Pain; Periaqueductal Gray; Piperidines; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Receptors, CXCR4; Rimonabant

2008
The effect of the palmitoylethanolamide analogue, palmitoylallylamide (L-29) on pain behaviour in rodent models of neuropathy.
    British journal of pharmacology, 2007, Volume: 151, Issue:7

    Cannabinoids are associated with analgesia in acute and chronic pain states. A spectrum of central cannabinoid (CB(1)) receptor-mediated motor and psychotropic side effects limit their therapeutic potential. Here, we investigate the analgesic effect of the palmitoylethanolamide (PEA) analogue, palmitoylallylamide (L-29), which via inhibition of fatty acid amide hydrolase (FAAH) may potentiate endocannabinoids thereby avoiding psychotropic side effects.. The in vivo analysis of the effect of L-29 on measures of pain behaviour in three rat models of neuropathic pain.. Systemically administered L-29 (10 mg kg(-1)) reduced hypersensitivity to mechanical and thermal stimuli in the partial sciatic nerve injury (PSNI) model of neuropathic pain; and mechanical hypersensitivity in a model of antiretroviral (ddC)-associated hypersensitivity and a model of varicella zoster virus (VZV)-associated hypersensitivity. The effects of L-29 were comparable to those of gabapentin (50 mg kg(-1)). The CB(1) receptor antagonist SR141716a (1 mg kg(-1)) and the CB(2) receptor antagonist SR144528 (1 mg kg(-1)) reduced the effect of L-29 on hypersensitivity in the PSNI and ddC models, but not in the VZV model. The peroxisome proliferator-activated receptor-alpha antagonist, MK-886 (1 mg kg(-1)), partially attenuated the effect of L-29 on hypersensitivity in the PSNI model. L-29 (10 mg kg(-1)) significantly attenuated thigmotactic behaviour in the open field arena without effect on locomotor activity.. L-29 produces analgesia in a range of neuropathic pain models. This presents L-29 as a novel analgesic compound that may target the endogenous cannabinoid system while avoiding undesirable side effects associated with direct cannabinoid receptor activation.

    Topics: Amides; Amines; Animals; Behavior, Animal; Camphanes; Cyclohexanecarboxylic Acids; Dose-Response Relationship, Drug; Endocannabinoids; Ethanolamines; Gabapentin; gamma-Aminobutyric Acid; Hindlimb; Indoles; Injections, Intraperitoneal; Male; Pain; Pain Measurement; Pain Threshold; Palmitic Acids; Physical Stimulation; Piperidines; PPAR alpha; Pyrazoles; Rats; Rats, Wistar; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Rimonabant; Sciatic Neuropathy; Temperature; Zalcitabine

2007
The antinociceptive effect of Delta9-tetrahydrocannabinol in the arthritic rat involves the CB(2) cannabinoid receptor.
    European journal of pharmacology, 2007, Sep-10, Volume: 570, Issue:1-3

    Cannabinoid CB(2) receptors have been implicated in antinociception in animal models of both acute and chronic pain. We evaluated the role both cannabinoid CB(1) and CB(2) receptors in mechanonociception in non-arthritic and arthritic rats. The antinociceptive effect of Delta(9)-tetrahydrocannabinol (Delta(9)THC) was determined in rats following administration of the cannabinoid CB(1) receptor-selective antagonist, SR141716A, the cannabinoid CB(2) receptor-selective antagonist, SR144528, or vehicle. Male Sprague-Dawley rats were rendered arthritic using Freund's complete adjuvant and tested for mechanical hyperalgesia in the paw-pressure test. Arthritic rats had a baseline paw-pressure of 83 +/- 3.6 g versus a paw-pressure of 177 +/- 6.42 g in non-arthritic rats. SR144528 or SR141716A (various doses mg/kg; i.p.) or 1:1:18 (ethanol:emulphor:saline) vehicle were injected 1 h prior to Delta(9)THC (4 mg/kg; i.p) or 1:1:18 vehicle and antinociception determined 30min post Delta(9)THC. AD(50)'s for both antagonists were calculated with 95% confidence limits. In addition, midbrain and spinal cord were removed for determination of cannabinoid CB(1) and CB(2) receptor protein density in the rats. SR144528 significantly attenuated the antinociceptive effect of Delta(9)THC in the arthritic rats [AD(50) = 3.3 (2.7-4) mg/kg], but not in the non-arthritic rats at a dose of 10/mg/kg. SR141716A significantly attenuated Delta(9)THC-induced antinociception in both the non-arthritic [AD(50) = 1.4 (0.8-2) mg/kg] and arthritic rat [AD(50) = 2.6 (1.8-3.1) mg/kg]. SR141716A or SR144528 alone did not result in a hyperalgesic effect as compared to vehicle. Our results indicate that the cannabinoid CB(2) receptor plays a critical role in cannabinoid-mediated antinociception, particularly in models of chronic inflammatory pain.

    Topics: Analgesics; Animals; Arthritis, Experimental; Camphanes; Dronabinol; Male; Mesencephalon; Pain; Piperidines; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Rimonabant; Spinal Cord

2007
The inhibition of monoacylglycerol lipase by URB602 showed an anti-inflammatory and anti-nociceptive effect in a murine model of acute inflammation.
    British journal of pharmacology, 2007, Volume: 152, Issue:5

    2-arachidonoylglycerol (2-AG) is an endocannabinoid whose hydrolysis is predominantly catalysed by the enzyme monoacylglycerol lipase (MAGL). The development of MAGL inhibitors could offer an opportunity to investigate the anti-inflammatory and anti-nociceptive role of 2-AG, which have not yet been elucidated. On these bases, URB602, a MAGL inhibitor, was tested in a murine model of inflammation/inflammatory pain.. Acute inflammation was induced by intraplantar injection of lambda-carrageenan into mice. The highest dose to be employed has been selected performing the tetrad assays for cannabimimetic activity in mice. URB602 anti-inflammatory and anti-nociceptive efficacy (assessed by plethysmometer and plantar test, respectively) was evaluated both in a preventive regimen (drug administered 30 min before carrageenan) and in a therapeutic regimen (URB602 administered 30 min after carrageenan). To elucidate the cannabinoid receptor involvement, rimonabant and SR144528, CB1 and CB2 selective antagonists, respectively, were given 15 min before URB602.. Systemic administration of URB602 elicited a dose-dependent anti-oedemigen and anti-nociceptive effect that was reversed exclusively by the CB2 receptor antagonist. The efficacy of URB602 persisted also when the compound was administered in a therapeutic regimen, suggesting the ability of URB602 to improve established disease.. The present report highlighted the ability of the selective MAGL inhibitor, URB602, to prevent and treat an acute inflammatory disease without producing adverse psychoactive effects. The data presented herein also contributed to clarify the physiological role of 2-AG in respect to inflammatory reactions, suggesting its protective role in the body.

    Topics: Acute Disease; Animals; Biphenyl Compounds; Body Temperature; Camphanes; Carrageenan; Disease Models, Animal; Dose-Response Relationship, Drug; Edema; Hindlimb; Hyperalgesia; Inflammation; Injections, Intraperitoneal; Male; Mice; Mice, Inbred C57BL; Monoacylglycerol Lipases; Pain; Pain Measurement; Pain Threshold; Piperidines; Pyrazoles; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Rimonabant

2007
Non-cannabinoid CB1, non-cannabinoid CB2 antinociceptive effects of several novel compounds in the PPQ stretch test in mice.
    European journal of pharmacology, 2006, Sep-28, Volume: 546, Issue:1-3

    The analgesic and anti-hyperalgesic effects of cannabinoid- and vanilloid-like compounds, plus the fatty acid amide hydrolase (FAAH) inhibitor Cyclohexylcarbamic acid 3'-carbamoyl-biphenyl-3-yl ester (URB597), and acetaminophen, were evaluated in the phenyl-p-quinone (PPQ) pain model, using different routes of administration in combination with opioid and cannabinoid receptor antagonists. All the compounds tested produced analgesic effects. Delta(9)-tetrahydrocannabinol (Delta(9)-THC) and (R)-(+)-arachidonyl-1'-hydroxy-2'-propylamide ((R)-methanandamide) were active by three routes of administration: i.p., s.c. and, p.o. Delta(9)-THC produced ED(50)s of 2.2 mg/kg (0.3-15.6) i.p., 9 mg/kg (4.3-18.9) s.c., and 6.4 mg/kg (5.5-7.6) p.o. Similarly, (R)-methanandamide yielded ED(50)s of 2.9 mg/kg (1-8) i.p., 11 mg/kg (7-17) s.c., and 11 mg/kg (0.9-134) p.o. N-vanillyl-arachidonyl-amide (arvanil) was active by two routes, producing ED(50)s of 4.7 mg/kg (3.0-7.4) s.c. and 0.06 mg/kg (0.02-0.2) i.p. Palmitoylethanolamide, URB597, and acetaminophen were active i.p., resulting in ED(50)s of 3.7 mg/kg (3.2-4.2), 22.9 mg/kg (11.1-47.2), and 160 mg/kg (63-405), respectively. None of the cannabinoid or opioid receptor antagonists tested blocked the compounds evaluated, with two exceptions: the antinociceptive effects of Delta(9)-THC and URB597 were completely blocked by SR141716A, a cannabinoid CB(1) receptor antagonist. Western immunoassays performed using three opioid receptor antibodies, a cannabinoid CB(1) receptor antibody and a transient receptor potential vanilloid type 1(TRPV(1)) receptor antibody, yielded no change in receptor protein levels after short-term arvanil, (R)-methanandamide or Delta(9)-THC administration. These data suggest that all the compounds tested, except Delta(9)-THC and URB597, produced analgesia via a non-cannabinoid CB(1), non-cannabinoid CB(2) pain pathway not yet identified.

    Topics: Acetaminophen; Amides; Analgesics; Animals; Arachidonic Acids; Benzamides; Benzoquinones; Camphanes; Capsaicin; Carbamates; Dose-Response Relationship, Drug; Dronabinol; Endocannabinoids; Ethanolamines; Hyperalgesia; Male; Mesencephalon; Mice; Mice, Inbred ICR; Narcotic Antagonists; Pain; Palmitic Acids; Piperidines; Pyrazoles; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Receptors, Opioid; Rimonabant; Spinal Cord; TRPV Cation Channels

2006
Effects of a cannabinoid agonist on spinal nociceptive neurons in a rodent model of neuropathic pain.
    Journal of neurophysiology, 2006, Volume: 96, Issue:6

    The effects of the synthetic cannabinoid WIN 55,212-2 on heat-evoked firing of spinal wide dynamic range (WDR) neurons were examined in a rodent model of neuropathic pain. Fifty-eight WDR neurons (1 cell/animal) were recorded from the ipsilateral spinal dorsal horns of rats with chronic constriction injury (CCI) and sham-operated controls. Relative to sham-operated controls, neurons recorded in CCI rats showed elevations in spontaneous firing, noxious heat-evoked responses, and afterdischarge firing as well as increases in receptive field size. WIN 55,212-2 (0.0625, 0.125, and 0.25 mg/kg, intravenous) dose-dependently suppressed heat-evoked activity and decreased the receptive field areas of dorsal horn WDR neurons in both nerve injured and control rats with a greater inhibition in CCI rats. At the dose of 0.125 mg/kg iv, WIN 55,212-2 reversed the hyperalgesia produced by nerve injury. The effect of intravenous administration of WIN 55,212-2 appears to be centrally mediated because administration of the drug directly to the ligated nerve did not suppress the heat-evoked neuronal activity in CCI rats. Pretreatment with the cannabinoid CB(1) receptor antagonists SR141716A or AM251, but not the CB(2) antagonist SR144528, blocked the effects. These results provide a neural basis for reports of potent suppression by cannabinoids of the abnormal sensory responses that result from nerve injury.

    Topics: Analgesics; Animals; Behavior, Animal; Benzoxazines; Camphanes; Cannabinoid Receptor Agonists; Cannabinoid Receptor Antagonists; Dose-Response Relationship, Drug; Electrophysiology; Hot Temperature; Hyperalgesia; In Vitro Techniques; Morpholines; Naphthalenes; Neurons; Nociceptors; Pain; Peripheral Nervous System Diseases; Piperidines; Posterior Horn Cells; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Rimonabant; Spinal Cord

2006
Involvement of cannabinoid receptors in inflammatory hypersensitivity to colonic distension in rats.
    Neurogastroenterology and motility, 2006, Volume: 18, Issue:10

    Activation of cannabinoid CB1 and CB2 receptors is known to attenuate nociception and hyperalgesia in somatic inflammatory conditions. The aim of this study was to determine whether cannabinoids modulate colonic sensitivity in basal and inflammatory conditions. The effects of CB1 and CB2 receptor agonists and antagonists on the abdominal contractile response to colorectal distension (CRD) in basal conditions and after 2,4,6-trinitrobenzenesulphonic acid-induced colitis were investigated. As previously described, colitis triggered a hypersensitivity to CRD. In basal conditions, both CB1 (WIN 55212-2) and CB2 (JWH 015) agonists reduced the abdominal response to CRD at a dose of 1 mg kg(-1), i.p. Both compounds were active at a lower dose (0.1 mg kg(-1)) abolishing the hypersensitivity induced by colitis. Administered alone, CB1 (Rimonabant) and CB2 (SR 144528) receptor antagonists (10 mg kg(-1)) had no effect on basal sensitivity. In contrast, the CB1, but not the CB2, receptor antagonist enhanced colitis-induced hyperalgesia. It is concluded that colonic inflammation enhances the antinociceptive action of CB1 and CB2 receptor agonists, and activates an endogenous, CB1 receptor mediated, antinociceptive pathway.

    Topics: Animals; Benzoxazines; Calcium Channel Blockers; Camphanes; Colitis; Colon; Dose-Response Relationship, Drug; Indoles; Inflammation; Male; Manometry; Morpholines; Muscle Contraction; Muscle, Smooth; Naphthalenes; Nociceptors; Pain; Piperidines; Pressure; Pyrazoles; Rats; Rats, Wistar; Receptors, Cannabinoid; Rimonabant; Trinitrobenzenesulfonic Acid

2006
Cannabinoid CB2 receptor agonist activity in the hindpaw incision model of postoperative pain.
    European journal of pharmacology, 2005, Dec-19, Volume: 527, Issue:1-3

    The identification of peripherally expressed CB2 receptors and reports that the selective activation of cannabinoid CB2 receptors produces antinociception without traditional cannabinergic side effects suggests that selective cannabinoid CB2 receptor agonists might be useful in the management of pain. In a rat hindpaw incision model, we examined the antiallodynic activity of the selective cannabinoid CB2 receptor agonists AM1241 (3-30 mg/kg i.p.), GW405833 (3-30 mg/kg i.p.), and HU-308 (0.3-30 mg/kg i.p.). The rank order for efficacy in the hindpaw incision model following a dose of 10 mg/kg, i.p. was AM1241 > GW405833 = HU-308, and the selective cannabinoid CB2 receptor antagonist, SR144528, reversed the antiallodynic effect of HU-308. Together, these data suggest that selective cannabinoid CB2 receptor agonists might represent a new class of postoperative analgesics.

    Topics: Animals; Camphanes; Cannabinoids; Drug Administration Schedule; Foot Injuries; Hindlimb; Indoles; Male; Models, Animal; Morpholines; Pain; Pain Measurement; Pain, Postoperative; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB2; Time Factors

2005
Evidence that CB-1 and CB-2 cannabinoid receptors mediate antinociception in neuropathic pain in the rat.
    Pain, 2004, Volume: 109, Issue:1-2

    The roles of the two cannabinoid receptor subtypes, CB-1 and CB-2, have not been clarified in cannabinoid-mediated analgesia. We investigated the efficacy of the non-selective cannabinoid receptor agonist CP55,940 in the modulation of responses in the rat to both acute pain (tail flick) and neuropathic pain (tactile allodynia following chronic L5/6 spinal nerve ligation). Responses were also assessed in the presence of the CB-1 antagonist SR141716A (SR1) and the CB-2 antagonist SR144528 (SR2). CP55,940 attenuated tactile allodynia (ED(50) 0.04 mg/kg i.t. (95% CI 0.032-0.044 mg/kg), 0.12 mg/kg i.p. (95% CI 0.10-0.15 mg/kg)) and induced thermal antinociception (ED(50) tail flick 0.07 mg/kg i.t. (95% CI 0.05-0.10 mg/kg), 0.17 mg/kg i.p. (95% CI 0.11-0.26 mg/kg)). SR1 0.5 mg/kg i.t. attenuated the antinociceptive effect of CP55,940 in both modalities. However, SR1 1.0 mg/kg i.p. decreased tail flick latency but had no effect on tactile allodynia antinociception. In contrast, SR2 1.0 mg/kg i.p. significantly decreased the effect of i.p. CP55,940 on both tail flick antinociception and tactile allodynia (P<0.005). The combination of SR1 and SR2 (i.p.) had an additive effect in decreasing the antinociception induced by CP55,940 on tail flick responses (P<0.005). These results suggest a role for CB-2 receptor-mediated antinociception in both acute and neuropathic pain in addition to centrally located CB-1 mechanisms.

    Topics: Analgesics; Analysis of Variance; Animals; Behavior, Animal; Camphanes; Cyclohexanols; Dose-Response Relationship, Drug; Drug Administration Routes; Drug Interactions; Ligation; Male; Nociceptors; Pain; Pain Measurement; Piperidines; Pyrazoles; Rats; Rats, Sprague-Dawley; Reaction Time; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Rimonabant; Spinal Nerves; Time Factors

2004
A peripheral cannabinoid mechanism suppresses spinal fos protein expression and pain behavior in a rat model of inflammation.
    Neuroscience, 2003, Volume: 117, Issue:3

    The present studies were conducted to test the hypothesis that systemically inactive doses of cannabinoids suppress inflammation-evoked neuronal activity in vivo via a peripheral mechanism. We examined peripheral cannabinoid modulation of spinal Fos protein expression, a marker of neuronal activity, in a rat model of inflammation. Rats received unilateral intraplantar injections of carrageenan (3%). In behavioral studies, carrageenan induced allodynia and mechanical hyperalgesia in response to stimulation with von Frey monofilaments. The cannabinoid agonist WIN55,212-2 (30 microg intraplantarly), administered concurrently with carrageenan, attenuated carrageenan-evoked allodynia and hyperalgesia relative to control conditions. In immunocytochemical studies, WIN55,212-2 suppressed the development of carrageenan-evoked Fos protein expression in the lumbar dorsal horn of the spinal cord relative to vehicle treatment. The same dose administered systemically or to the noninflamed contralateral paw failed to alter either carrageenan-evoked allodynia and hyperalgesia or carrageenan-evoked Fos protein expression, consistent with a peripheral site of action. The suppressive effects of WIN55,212-2 (30 microg intraplantarly) on carrageenan-evoked Fos protein expression and pain behavior were blocked by local administration of either the CB(2) antagonist SR144528 (30 microg intraplantarly) or the CB(1) antagonist SR141716A (100 microg intraplantarly). WIN55,212-3, the enantiomer of the active compound, also failed to suppress carrageenan-evoked Fos protein expression. These data provide direct evidence that a peripheral cannabinoid mechanism suppresses the development of inflammation-evoked neuronal activity at the level of the spinal dorsal horn and implicate a role for CB(2) and CB(1) in peripheral cannabinoid modulation of inflammatory nociception.

    Topics: Analgesics; Animals; Behavior, Animal; Benzoxazines; Camphanes; Cannabinoids; Carrageenan; Disease Models, Animal; Drug Administration Routes; Drug Interactions; Edema; Functional Laterality; Gene Expression Regulation; Immunohistochemistry; Inflammation; Male; Mechanoreceptors; Morpholines; Naphthalenes; Pain; Pain Measurement; Physical Stimulation; Piperidines; Proto-Oncogene Proteins c-fos; Pyrazoles; Rats; Rats, Sprague-Dawley; Rimonabant; Spinal Cord; Time Factors

2003
A cannabinoid agonist differentially attenuates deep tissue hyperalgesia in animal models of cancer and inflammatory muscle pain.
    Pain, 2003, Volume: 103, Issue:1-2

    Pain associated with cancer and chronic musculoskeletal disorders can be difficult to control. We used murine models of cancer and inflammatory muscle pain to examine whether the cannabinoid receptor agonist WIN55,212-2 reduces hyperalgesia originating in deep tissues. C3H/He mice were anesthetized and implanted with osteolytic NCTC clone 2472 cells into the humeri or injected with 4% carrageenan into the triceps muscles of both forelimbs. At the time of peak hyperalgesia, WIN55,212-2 (1-30mg/kg) or vehicle was administered intraperitoneally and forelimb grip force was measured 0.5-24h later. WIN55,212-2 produced time- and dose-related antihyperalgesia in both models. A 10mg/kg dose of WIN55,212-2 fully reversed carrageenan-evoked muscle hyperalgesia. However, 30mg/kg of WIN55,212-2 attenuated tumor-evoked hyperalgesia only approximately 50%. After controlling for the difference in magnitude of hyperalgesia between the two models, WIN55,212-2 was still more potent at reducing hyperalgesia in the inflammatory model. In the cancer pain model, the antihyperalgesic effect of WIN55,212-2 was partially blocked by pretreatment with the selective CB1 (SR141716A) but not the CB2 (SR144528) receptor antagonist. In contrast, both antagonists blocked antihyperalgesic effects of WIN55,212-2 on carrageenan-evoked muscle hyperalgesia. Catalepsy and loss of motor coordination, known side effects of cannabinoids, did not account for the antihyperalgesia produced by WIN55,212-2. These data show that cannabinoids attenuate deep tissue hyperalgesia produced by both cancer and inflammatory conditions. Interestingly, cannabinoids differentially modulated carrageenan- and tumor-evoked hyperalgesia in terms of potency and receptor subtypes involved suggesting that differences in underlying mechanisms may exist between these two models of deep tissue pain.

    Topics: Animals; Benzoxazines; Calcium Channel Blockers; Camphanes; Cannabinoids; Carrageenan; Catalepsy; Disease Models, Animal; Dopamine Antagonists; Dose-Response Relationship, Drug; Drug Interactions; Fibrosarcoma; Haloperidol; Hand Strength; Humerus; Hyperalgesia; Male; Mice; Mice, Inbred C3H; Morpholines; Myositis; Naphthalenes; Neoplasm Transplantation; Neoplasms; Pain; Piperidines; Psychomotor Performance; Pyrazoles; Receptors, Cannabinoid; Receptors, Drug; Rimonabant

2003
Selective activation of cannabinoid CB(2) receptors suppresses spinal fos protein expression and pain behavior in a rat model of inflammation.
    Neuroscience, 2003, Volume: 119, Issue:3

    Activation of cannabinoid CB(2) receptors attenuates thermal nociception in untreated animals while failing to produce centrally mediated effects such as hypothermia and catalepsy [Pain 93 (2001) 239]. The present study was conducted to test the hypothesis that activation of CB(2) in the periphery suppresses the development of inflammatory pain as well as inflammation-evoked neuronal activity at the level of the CNS. The CB(2)-selective cannabinoid agonist AM1241 (100, 330 micrograms/kg i.p.) suppressed the development of carrageenan-evoked thermal and mechanical hyperalgesia and allodynia. The AM1241-induced suppression of carrageenan-evoked behavioral sensitization was blocked by the CB(2) antagonist SR144528 but not by the CB(1) antagonist SR141716A. Intraplantar (ipl) administration of AM1241 (33 micrograms/kg ipl) suppressed hyperalgesia and allodynia following administration to the carrageenan-injected paw but was inactive following administration in the contralateral (noninflamed) paw, consistent with a local site of action. In immunocytochemical studies, AM1241 suppressed spinal Fos protein expression, a marker of neuronal activity, in the carrageenan model of inflammation. AM1241 suppressed carrageenan-evoked Fos protein expression in the superficial and neck region of the dorsal horn but not in the nucleus proprius or the ventral horn. The suppression of carrageenan-evoked Fos protein expression induced by AM1241 was blocked by coadministration of SR144528 in all spinal laminae. These data provide evidence that actions at cannabinoid CB(2) receptors are sufficient to suppress inflammation-evoked neuronal activity at rostral levels of processing in the spinal dorsal horn, consistent with the ability of AM1241 to normalize nociceptive thresholds and produce antinociception in inflammatory pain states.

    Topics: Analgesics; Animals; Camphanes; Cannabinoids; Carrageenan; Disease Models, Animal; Drug Interactions; Hyperalgesia; Inflammation; Male; Nociceptors; Pain; Pain Threshold; Piperidines; Posterior Horn Cells; Proto-Oncogene Proteins c-fos; Pyrazoles; Rats; Rats, Sprague-Dawley; Reaction Time; Receptor, Cannabinoid, CB2; Receptors, Cannabinoid; Receptors, Drug; Rimonabant

2003
Decrease in efficacy and potency of nonsteroidal anti-inflammatory drugs by chronic delta(9)-tetrahydrocannabinol administration.
    The Journal of pharmacology and experimental therapeutics, 2002, Volume: 303, Issue:1

    Cannabinoids have been shown to increase the release of arachadonic acid, whereas nonsteroidal anti-inflammatory drugs (NSAIDs) have been shown to decrease the analgesic effects of cannabinoids. We evaluated the antinociceptive effects of chronic administration of Delta(9)-tetrahydrocannabinol (Delta(9)-THC), anandamide (an endogenous cannabinoid), arachadonic acid, ethanolamine, and methanandamide on several NSAIDs via p.o. and/or i.p. routes of administration using the mouse p-phenylquinone (PPQ) test, a test for visceral nociception. Our studies with a cannabinoid receptor (CB1) antagonist [N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboximide hydrochloride (SR141716A)], a CB2 antagonist [N-((1S)-endo-1,3,3-trimethyl-bicyclo-heptan-2-yl]-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-pyrazole-3-carboxamide) (SR144528)], and an another CB2 agonist [1,1-dimethylbutyl-1-deoxy-Delta(9)-THC (JWH-133)] were performed to better characterize PPQ interactions with cannabinoid receptors. The acute affects of Delta(9)-THC were blocked by SR141716A (i.p.) and partially blocked by SR144528 (i.p.). When NSAIDs (p.o.) were administered, the ED(50) values were as follows: 23 mg/kg aspirin, 3 mg/kg indomethacin, 5 mg/kg celecoxib, 3 mg/kg ketorolac, 57 mg/kg acetaminophen (32.3-99.8), and 0.8 mg/kg diclofenac (0.1-4.9). In animals given chronic Delta(9)-THC, only diclofenac and acetaminophen were active. Conversely, chronic methanandamide (i.p.) did not alter the antinociceptive effects of the NSAIDs. Neither the CB1 or CB2 antagonist blocked the effects of the NSAIDs. The effects of chronic arachadonic acid, ethanolamine, and anandamide could not be evaluated. In summary, our data indicate that chronic Delta(9)-THC alters the cyclooxygenase system. Alternatively, the data suggest that this alteration is not due to chronic endogenous cannabinoid release. Based upon these data, we hypothesize that human subjects who are chronic users of Delta(9)-THC may not respond to analgesic treatment with the above NSAIDs.

    Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Arachidonic Acid; Arachidonic Acids; Aspirin; Camphanes; Diclofenac; Dose-Response Relationship, Drug; Dronabinol; Endocannabinoids; Ethanolamines; Indomethacin; Kinetics; Male; Mice; Mice, Inbred ICR; Pain; Polyunsaturated Alkamides; Pyrazoles; Receptors, Cannabinoid; Receptors, Drug

2002
Arvanil-induced inhibition of spasticity and persistent pain: evidence for therapeutic sites of action different from the vanilloid VR1 receptor and cannabinoid CB(1)/CB(2) receptors.
    European journal of pharmacology, 2002, Mar-29, Volume: 439, Issue:1-3

    Activation of cannabinoid receptors causes inhibition of spasticity, in a mouse model of multiple sclerosis, and of persistent pain, in the rat formalin test. The endocannabinoid anandamide inhibits spasticity and persistent pain. It not only binds to cannabinoid receptors but is also a full agonist at vanilloid receptors of type 1 (VR1). We found here that vanilloid VR1 receptor agonists (capsaicin and N-N'-(3-methoxy-4-aminoethoxy-benzyl)-(4-tert-butyl-benzyl)-urea [SDZ-249-665]) exhibit a small, albeit significant, inhibition of spasticity that can be attenuated by the vanilloid VR1 receptor antagonist, capsazepine. Arvanil, a structural "hybrid" between capsaicin and anandamide, was a potent inhibitor of spasticity at doses (e.g. 0.01 mg/kg i.v.) where capsaicin and cannabinoid CB(1) receptor agonists were ineffective. The anti-spastic effect of arvanil was unchanged in cannabinoid CB(1) receptor gene-deficient mice or in wildtype mice in the presence of both cannabinoid and vanilloid receptor antagonists. Likewise, arvanil (0.1-0.25 mg/kg) exhibited a potent analgesic effect in the formalin test, which was not reversed by cannabinoid and vanilloid receptor antagonists. These findings suggest that activation by arvanil of sites of action different from cannabinoid CB(1)/CB(2) receptors and vanilloid VR1 receptors leads to anti-spastic/analgesic effects that might be exploited therapeutically.

    Topics: Animals; Arachidonic Acids; Benzoxazines; Camphanes; Cannabinoid Receptor Modulators; Capsaicin; Disease Models, Animal; Dose-Response Relationship, Drug; Genotype; Mice; Mice, Inbred Strains; Mice, Knockout; Morpholines; Multiple Sclerosis; Muscle Spasticity; Naphthalenes; Pain; Pain Measurement; Piperidines; Pyrazoles; Receptors, Cannabinoid; Receptors, Drug; Rimonabant

2002
CB1 and CB2 cannabinoid receptors are implicated in inflammatory pain.
    Pain, 2002, Volume: 96, Issue:3

    The cannabinoid agonist, HU210 has been evaluated in vivo in nociceptive and inflammatory pain models in the rat. The ED50 for the anti-nociceptive (increasing mechanical withdrawal threshold) effect was 0.1 mg/kg-1 i.p., and for anti-hypersensitivity and anti-inflammatory activity was 5 g/kg-1 i.p. (in the carrageenan model). The selective CB1 antagonist, AM281 (0.5 microg/kg-1 i.p.) reversed effects of HU210 (10 and 30 microg/kg-1 i.p.) in both nociceptive and inflammatory models of hypersensitivity. The selective CB2 antagonist, SR144528 (1 mg/kg-1 i.p.) antagonised effects of HU210 (30 microg/kg-1 i.p.) in the carrageenan induced inflammatory hypersensitivity. The CB2 agonist, 1-(2,3-Dichlorobenzoyl)-5-methoxy-2-methyl-(2-(morpholin-4-yl)ethyl)-1H-indole (GW405833) inhibited the hypersensitivity and was anti-inflammatory in vivo. These effects were blocked by SR144528. These findings suggest that CB1 receptors are involved in nociceptive pain and that both CB1 and CB2 receptors are involved in inflammatory hypersensitivity. Future studies will investigate effects on identified inflammatory cells within the inflamed tissue to further elucidate the role of cannabinoid receptors.

    Topics: Acute Disease; Animals; Camphanes; Cannabinoids; Carrageenan; Dronabinol; Hypersensitivity; Indoles; Male; Morpholines; Neurogenic Inflammation; Nociceptors; Pain; Pyrazoles; Rats; Rats, Inbred Strains; Receptor, Cannabinoid, CB2; Receptors, Cannabinoid; Receptors, Drug

2002
Antinociceptive activity of the endogenous fatty acid amide, palmitylethanolamide.
    European journal of pharmacology, 2001, May-11, Volume: 419, Issue:2-3

    The endogenous fatty acid ethanolamide, palmitylethanolamide, alleviated, in a dose-dependent manner, pain behaviors elicited in mice by injections of formalin (5%, intraplantar), acetic acid (0.6%, 0.5 ml per animal, intraperitoneal, i.p.), kaolin (2.5 mg per animal, i.p.), and magnesium sulfate (120 mg per kg, i.p.). The antinociceptive effects of palmitylethanolamide were prevented by the cannabinoid CB2 receptor antagonist SR144528 [N-([1s]-endo-1.3.3-trimethylbicyclo[2.3.1]heptan-2-yl)-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-pyrazole-3-carboxamide], not by the cannabinoid CB1 receptor antagonist SR141716A [N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide x HCl]. By contrast, palmitylethanolamide had no effect on capsaicin-evoked pain behavior or thermal nociception. The endogenous cannabinoid, anandamide (arachidonylethanolamide), alleviated nociception in all tests (formalin, acetic acid, kaolin, magnesium sulfate, capsaicin and hot plate). These effects were prevented by the cannabinoid CB1 receptor antagonist SR141716A, not the cannabinoid CB2 receptor antagonist SR141716A. Additional fatty acid ethanolamides (oleylethanolamide, myristylethanolamide, palmitoleylethanolamide, palmitelaidylethanolamide) had little or no effect on formalin-evoked pain behavior, and were not investigated in other pain models. These results support the hypothesis that endogenous palmitylethanolamide participates in the intrinsic control of pain initiation. They also suggest that the putative receptor site activated by palmitylethanolamide may provide a novel target for peripherally acting analgesic drugs.

    Topics: Amides; Analgesics; Analysis of Variance; Animals; Arachidonic Acids; Calcium Channel Blockers; Camphanes; Dose-Response Relationship, Drug; Drug Synergism; Endocannabinoids; Ethanolamines; Formaldehyde; Male; Mice; Pain; Palmitic Acids; Polyunsaturated Alkamides; Pyrazoles

2001