arachidonyl-2-chloroethylamide and Disease-Models--Animal

Endovascular perforation was performed to establish a SAH model of rats. ACEA was administered intraperitoneally 1 h after SAH. The CB1R antagonist AM251 was injected intraperitoneally 1 h before SAH induction. Adenoassociated virus- (AAV-) Nrf1 shRNA was infused into the lateral ventricle 3 weeks before SAH induction. Neurological tests, immunofluorescence, DHE, TUNEL, Nissl staining, transmission electron microscopy (TEM), and Western blot were performed.. The expression of CB1R, Nrf1, PINK1, Parkin, and LC3II increased and peaked at 24 h after SAH. ACEA treatment exhibited the antioxidative stress and antiapoptosis effects after SAH. In addition, ACEA treatment increased the expression of Nrf1, PINK1, Parkin, LC3II, and Bcl-xl but repressed the expression of Romo-1, Bax, and cleaved caspase-3. Moreover, the TEM results demonstrated that ACEA promoted the formation of mitophagosome and maintained the normal mitochondrial morphology of neurons. The protective effect of ACEA was reversed by AM251 and Nrf1 shRNA, respectively.. This study demonstrated that ACEA alleviated oxidative stress and neurological dysfunction by promoting mitophagy after SAH, at least in part via the CB1R/Nrf1/PINK1 signaling pathway.

Topics: Animals; Antioxidants; Apoptosis; Arachidonic Acids; Disease Models, Animal; Gene Knockdown Techniques; Male; Mitophagy; Neurons; Neuroprotective Agents; Nuclear Respiratory Factor 1; Oxidative Stress; Piperidines; Protein Kinases; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB1; Signal Transduction; Subarachnoid Hemorrhage; Treatment Outcome

l-Dopa is the most effective drug used for Parkinson's disease (PD), but after long-term treatment, the vast majority of PD patients develop abnormal involuntary movements (AIMs) termed l-Dopa-induced dyskinesia (LID). Cannabinoid receptors in the basal ganglia can modulate motor functions, but their role in the treatment of LID is controversial. Therefore, the aim of this study is to evaluate the motor behavior and mRNA expression of the cannabinoid receptor-1 (CB

Topics: Animals; Arachidonic Acids; Cannabinoid Receptor Agonists; Corpus Striatum; Disease Models, Animal; Dyskinesia, Drug-Induced; Gene Expression; Levodopa; Male; Oxidopamine; Parkinson Disease; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB1; RNA, Messenger

Rational polytherapy in the treatment of refractory epilepsy has been the main therapeutic modality for several years. In treatment with two or more antiepileptic drugs (AEDs), it is of particular importance that AEDs be selected based on their high anticonvulsant properties, minimal side effects, and impact on the formation of new neurons. The aim of the study was to conduct an in vivo evaluation of the relationship between treatments with synthetic cannabinoid arachidonyl-2'-chloroethylamide (ACEA) alone or in combination with valproic acid (VPA) and hippocampal neurogenesis in a mouse pilocarpine model of epilepsy. All studies were performed on adolescent male CB57/BL mice with using the following drugs: VPA (10 mg/kg), ACEA (10 mg/kg), phenylmethylsulfonyl fluoride (PMSF-a substance protecting ACEA against degradation by fatty acid hydrolase, 30 mg/kg), pilocarpine (PILO, a single dose of 290 mg/kg) and methylscopolamine (30 min before PILO to stop peripheral cholinergic effects of pilocarpine, 1 mg/kg). We evaluated the process of neurogenesis after a 10-day treatment with ACEA and VPA, alone and in combination. We observed a decrease of neurogenesis in the PILO control group as compared to the healthy control mice. Furthermore, ACEA + PMSF alone and in combination with VPA significantly increased neurogenesis compared to the PILO control group. In contrast, VPA 10-day treatment had no impact on the level of neurons in comparison to the PILO control group. The combination of ACEA, PMSF and VPA considerably stimulated the process of creating new cells, particularly neurons, while chronic administration of VPA itself had no influence on neurogenesis in the mouse pilocarpine model of epilepsy. The obtained results enabled an in vivo evaluation of neurogenesis after treatment with antiepileptic drugs in an experimental model of epilepsy.

Topics: Animals; Anticonvulsants; Arachidonic Acids; Astrocytes; Disease Models, Animal; Drug Therapy, Combination; Epilepsy; Immunohistochemistry; Male; Mice; Mice, Inbred C57BL; Microscopy, Confocal; Neurogenesis; Pilocarpine; Valproic Acid

Accumulating evidence indicates that cannabinoid CB1 receptor ligands play a pivotal role in seizures, not only in preclinical studies on animals, but also in clinical settings. This study was aimed at characterizing the influence of arachidonyl-2'-chloroethylamide (ACEA-a selective cannabinoid CB1 receptor agonist) co-administered with phenylmethylsulfonyl fluoride (PMSF) on the anticonvulsant potency of various antiepileptic drugs (clobazam, lacosamide, levetiracetam, phenobarbital, tiagabine and valproate) in the 6-Hz corneal stimulation model. Psychomotor seizures in male albino Swiss mice were evoked by a current (32 mA, 6 Hz, 3 s stimulus duration) delivered via corneal electrodes. Potential adverse effects produced by the antiepileptic drugs in combination with ACEA+PMSF were assessed using the chimney test (motor performance), passive avoidance task (remembering and acquisition of learning), and grip-strength test (muscular strength). Brain concentrations of antiepileptic drugs were measured by HPLC to exclude any pharmacokinetic contribution to the observed effect. ACEA (5 mg/kg, i.p.) + PMSF (30 mg/kg, i.p.) significantly potentiated the anticonvulsant potency of levetiracetam (P<0.05), but not that of clobazam, lacosamide, phenobarbital, tiagabine or valproate in the 6-Hz corneal stimulation model. Moreover, ACEA+PMSF did not significantly affect total brain concentrations of levetiracetam in mice. No behavioral side effects were observed in animals receiving combinations of the studied antiepileptic drugs with ACEA+PMSF. In conclusion, the combined administration of ACEA+PMSF with levetiracetam is associated with beneficial anticonvulsant pharmacodynamic interaction in the 6-Hz corneal stimulation model. The selective activation of cannabinoid CB1 receptor-mediated neurotransmission in the brain may enhance levetiracetam-related suppression of seizures in epilepsy patients, contributing to the efficacious treatment of epilepsy in future.

Topics: Acetamides; Animals; Anticonvulsants; Arachidonic Acids; Avoidance Learning; Benzodiazepines; Clobazam; Cornea; Disease Models, Animal; Drug Synergism; Drug Therapy, Combination; Electroshock; Epilepsy, Complex Partial; Lacosamide; Levetiracetam; Male; Mice; Muscle Strength; Nipecotic Acids; Phenobarbital; Phenylmethylsulfonyl Fluoride; Piracetam; Psychomotor Performance; Receptor, Cannabinoid, CB1; Tiagabine; Valproic Acid

Angiotensin (Ang) II and cannabinoids regulate physiologically relevant astroglial functions via receptor-mediated activation of Mitogen-activated protein kinases (MAPKs). In this study, we investigated the consequences of astroglial Ang II type 1 receptor (AT1R) and Cannabinoid type 1 receptor (CB1R) activation, alone and in combination, on MAPK activation in the presence and absence of hypertensive states. In addition, we also investigated a novel unidirectional crosstalk mechanism between AT1R and CB1R, that involves PKC-mediated phosphorylation of CB1R.. Astrocytes were isolated from the brainstem and cerebellum of Spontaneously hypertensive rats (SHRs) and normotensive Wistar rats. The cells were treated with either 100nM Ang II or 10nM Arachidonyl-2'-chloroethylamide (ACEA), both alone and in combination, for varying time periods, and the extent of phosphorylation of MAPKs, ERK and p38, and the phosphorylated forms of CB1R (p-CB1R), were measured using western blotting.. Ang II treatment resulted in a greater activation of MAPKs in SHR brainstem astrocytes, but not SHR cerebellar astrocytes when compared to Wistar rats. ACEA-mediated MAPK activation was significantly lower in brainstem astrocytes of SHRs when compared to Wistar rats. ACEA negatively modulates AT1R-mediated MAPK activation in both cerebellar and brainstem astrocytes of both models. The effect however was diminished in brainstem astrocytes. Ang II caused a significant increase in phosphorylation of CB1R in cerebellar astrocytes, while its effect was diminished in brainstem astrocytes of both models.. Both Ang II and ACEA-induced MAPK activation were significantly altered in SHR astrocytes when compared to Wistar astrocytes. A possible reduction in CB1R functionality, coupled with a hyperfunctional AT1R in the brainstem, could well be significant factors in the development of hypertensive states. AT1R-mediated phosphorylation of CB1R could be critical for impaired cerebellar development characterized by a hyperactive RAS.

Topics: Angiotensin II; Animals; Arachidonic Acids; Astrocytes; Blood Pressure; Cannabinoids; Disease Models, Animal; Humans; Hypertension; MAP Kinase Kinase 1; Phosphorylation; Rats; Rats, Inbred SHR; Receptor, Angiotensin, Type 1; Receptors, Cannabinoid

Cannabinoids have been suggested as a therapeutic target for a variety of brain disorders. Despite the presence of their receptors throughout the auditory system, little is known about how cannabinoids affect auditory function. We sought to determine whether administration of arachidonyl-2'-chloroethylamide (ACEA), a highly-selective CB

Topics: Acoustic Stimulation; Alpha Rhythm; Animals; Arachidonic Acids; Auditory Cortex; Behavior, Animal; Cannabinoid Receptor Agonists; Cytoprotection; Disease Models, Animal; Electrocorticography; Evoked Potentials, Auditory; Evoked Potentials, Auditory, Brain Stem; Female; Guinea Pigs; Hyperacusis; Male; Noise; Reaction Time; Receptor, Cannabinoid, CB1; Salicylic Acid; Signal Transduction; Time Factors; Tinnitus

One of the most common psychological consequences of stroke is post-stroke depression (PSD). While more than 30 percent of stroke patients eventually develop PSD, the neurobiological mechanisms underlying such a phenomenon have not been well investigated. Given the critical involvement of hypothalamic-pituitary-adrenal axis and endocannabinoid system in response to stressful stimuli, we evaluated the hypothesis that cannabinoid receptors in the hypothalamus are critical for modulation of post-stroke depression-like behaviors in rats. To this end, rats were treated with middle cerebral artery occlusion (MCAO) followed by chronic unpredictable mild stress (CUMS) treatment procedure. We then assessed the expression of CB1 and CB2 receptors in the hypothalamus, and evaluated the effects of pharmacological stimulations of CB1 or CB2 receptors on the expression and development of depression-like behaviors in PSD rats. We found that PSD rats exhibited decreased the expression of CB1 receptor, but not CB2 receptor, in the ventral medial hypothalamus (VMH). Such an effect was not observed in the dorsally adjacent brain regions. Furthermore, intra-VMH injections of CB2 receptor agonist, but not CB1 receptor agonist, attenuated the expression of depression-like behaviors in PSD rats. Finally, repeated intraperitoneal injections of CB1 or CB2 receptor agonists during CUMS treatment inhibited the development of depression-like behaviors in PSD rats. Taken together, these results suggest that decreased CB1 receptor expression is likely associated with the development of post-stroke depression, and CB2 receptor may be a potential therapeutic target for the treatment post-stroke depressive disorders.

Topics: Animals; Arachidonic Acids; Cannabinoid Receptor Agonists; Cannabinoids; Depression; Disease Models, Animal; Dose-Response Relationship, Drug; Exploratory Behavior; Food Preferences; Hypothalamus; Infarction, Middle Cerebral Artery; Male; Microinjections; Rats; Rats, Sprague-Dawley; Receptors, Cannabinoid; Stroke

Direct activation of the cannabinoid CB1 receptor in the dorsolateral periaqueductal gray (dlPAG) inhibits anxiety- and panic-related behaviours in experimental animals. It has remained unclear, however, whether the local endocannabinoid signalling is recruited as a protective mechanism against aversive stimuli.. The present study tested the hypothesis that the endocannabinoid system counteracts aversive responses in the dlPAG-stimulation model of panic attacks.. All drugs were infused into the dlPAG of rats. Local chemical stimulation with N-methyl-D-aspartate (NMDA, 1 nmol) was employed to induce panic-like behavioural and cardiovascular responses in freely moving and anaesthetized animals, respectively. The neuronal activity in the dlPAG was investigated by c-Fos immunohistochemistry.. The selective CB1 receptor agonist, ACEA (0.005-0.5 pmol), prevented the NMDA-induced panic-like escape responses. More interestingly, increasing the local levels of endogenous anandamide with a fatty acid amide hydrolase (FAAH) inhibitor, URB597 (0.3-3 nmol), prevented both the behavioural response and the increase in blood pressure induced by NMDA. The effect of URB597 (3 nmol) was reversed by the CB1 receptor antagonist, AM251 (0.1 nmol). Moreover, an otherwise ineffective and sub-threshold dose of NMDA (0.5 nmol) was able to induce a panic-like response if local CB1 receptors were previously blocked by AM251 (0.1 nmol). Finally, URB597 prevented the NMDA-induced neuronal activation of the dlPAG.. The endocannabinoid system in the dlPAG attenuates the behavioural, cellular and cardiovascular consequences of aversive stimuli. This process may be considered for the development of additional treatments against panic and other anxiety-related disorders.

Topics: Amidohydrolases; Animals; Anxiety; Arachidonic Acids; Behavior, Animal; Benzamides; Carbamates; Disease Models, Animal; Endocannabinoids; Enzyme Inhibitors; Male; N-Methylaspartate; Panic Disorder; Periaqueductal Gray; Piperidines; Polyunsaturated Alkamides; Pyrazoles; Rats; Rats, Wistar; Receptor, Cannabinoid, CB1

Panic attacks, a major feature of panic disorder, can be modelled in rats by exposing animals to stimuli that induce escape reactions, such as the elevated T-maze or the activation of the dorsolateral periaqueductal grey. Since the cannabinoid CB1 receptor modulates various types of aversive responses, this study tested the hypothesis that enhancement of endocannabinoid signalling in the dorsolateral periaqueductal grey inhibits panic-like reactions in rats. Local injection of the CB1 agonist, arachidonoyl 2-Chloroethylamide (0.005-0.5 pmol), attenuated the escape response from the open arm of the elevated T-maze, a panicolytic effect. The anandamide hydrolysis inhibitor, URB597 (0.3-3 nmol), did not induce consistent results. In the test of dorsolateral periaqueductal grey stimulation with d,l-homocysteic acid, arachidonoyl 2-Chloroethylamide, at the lowest dose, attenuated the escape reaction. The highest dose of URB597 also inhibited this response, contrary to the result obtained in the elevated T-maze. This effect was reversed by the CB1 antagonist, AM251 (100 pmol). The present results confirm the anti-aversive property of direct CB1 receptor activation in the dorsolateral periaqueductal grey. The effect of the anandamide hydrolysis inhibitor, however, could be detected only in a model employing direct stimulation of this structure. Altogether, these results suggest that anandamide signalling is recruited only under certain types of aversive stimuli.

Topics: Animals; Arachidonic Acids; Benzamides; Carbamates; Disease Models, Animal; Dose-Response Relationship, Drug; Endocannabinoids; Escape Reaction; Male; Maze Learning; Panic Disorder; Periaqueductal Gray; Piperidines; Polyunsaturated Alkamides; Pyrazoles; Rats; Rats, Wistar; Receptor, Cannabinoid, CB1; Signal Transduction

Transcriptional dysregulation is a major pathological feature of Huntington's disease (HD). The goal of this study was to understand how p65/RelA co-regulated genes, specifically those of the cytokine and endocannabinoid systems, were affected in HD. p65/RelA levels were lower in human HD tissue and R6/2 HD mice, as were the levels of the type 1 cannabinoid receptor (CB1), IL-1β, IL-8, CCL5, GM-CSF, MIP-1β, and TNFα, all of which may be regulated by p65/RelA. Activation of p65/RelA restored CB1 and CCL5 expression in STHdh cell models of HD. Therefore, p65/RelA activation may normalize the expression of some genes in HD.

Topics: Adult; Age Factors; Aged; Amidohydrolases; Animals; Arachidonic Acids; Cannabinoids; Cells, Cultured; Corpus Striatum; Cytokines; Disease Models, Animal; Endocannabinoids; Enzyme Inhibitors; Female; Gene Expression Regulation; Humans; Huntingtin Protein; Huntington Disease; Indoles; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Middle Aged; Nerve Tissue Proteins; Neurons; NF-kappa B; Nuclear Proteins; Receptor, Cannabinoid, CB1; Transcription Factor RelA; Trinucleotide Repeats; Young Adult

Studies have suggested that the endocannabinoid system is implicated in the pathophysiology of schizophrenia. We have recently reported that Spontaneously Hypertensive Rats (SHRs) present a deficit in social interaction that is ameliorated by atypical antipsychotics. In addition, SHRs display hyperlocomotion - reverted by atypical and typical antipsychotics. These results suggest that this strain could be useful to study negative symptoms (modeled by a decrease in social interaction) and positive symptoms (modeled by hyperlocomotion) of schizophrenia and the effects of potential drugs with an antipsychotic profile. The aim of this study was to investigate the effects of WIN55-212,2 (CB1/CB2 agonist), ACEA (CB1 agonist), rimonabant (CB1 inverse agonist), AM404 (anandamide uptake/metabolism inhibitor), capsaicin (agonist TRPV1) and capsazepine (antagonist TRPV1) on the social interaction and locomotion of control animals (Wistar rats) and SHRs. The treatment with rimonabant was not able to alter either the social interaction or the locomotion presented by Wistar rats (WR) and SHR at any dose tested. The treatment with WIN55-212,2 decreased locomotion (1mg/kg) and social interaction (0.1 and 0.3mg/kg) of WR, while the dose of 1mg/kg increased social interaction of SHR. The treatment with ACEA increased (0.3mg/kg) and decreased (1mg/kg) locomotion of both strain. The administration of AM404 increased social interaction and decreased locomotion of SHR (5mg/kg), and decreased social interaction and increased locomotion in WR (1mg/kg). The treatment with capsaicin (2.5mg/kg) increased social interaction of both strain and decreased locomotion of SHR (2.5mg/kg) and WR (0.5mg/kg and 2.5mg/kg). In addition, capsazepine (5mg/kg) decreased locomotion of both strains and increased (5mg/kg) and decreased (10mg/kg) social interaction of WR. Our results indicate that the schizophrenia-like behaviors displayed by SHR are differently altered by cannabinoid and vanilloid drugs when compared to control animals and suggest the endocannabinoid and the vanilloid systems as a potential target for the treatment of schizophrenia.

Topics: Analysis of Variance; Animals; Arachidonic Acids; Benzoxazines; Cannabinoid Receptor Modulators; Capsaicin; Disease Models, Animal; Dose-Response Relationship, Drug; Interpersonal Relations; Male; Morpholines; Motor Activity; Naphthalenes; Piperidines; Pyrazoles; Rats; Rats, Inbred SHR; Rats, Wistar; Rimonabant; Schizophrenia; Schizophrenic Psychology; TRPV Cation Channels

Interstitial cystitis is a debilitating bladder inflammation disorder. To date, the understanding of the causes of interstitial cystitis remains largely fragmentary and there is no effective treatment available. Recent experimental results have shown a functional role of the endocannabinoid system in urinary bladder. In this study, we evaluated the anti-inflammatory effect of selective cannabinoid CB1 and CB2 receptor agonists in a mouse model of interstitial cystitis. Bladder inflammation was induced in mice by lipopolysaccharide (LPS) and whole bladders were removed 24h later. LPS induced a significant increase of the contractile amplitude in spontaneous activity and a hypersensitivity to exogenous acetylcholine-induced contraction of whole-isolated bladder. Next, we evaluated the anti-inflammatory activity of cannabinoidergic compounds by pretreating mice with CB1 or CB2 selective agonist compounds, respectively ACEA and JWH015. Interestingly, JWH015, but not ACEA, antagonized LPS-induced bladder inflammation. Additionally, anti-inflammatory activity was studied by evaluation, leukocytes mucosa infiltration, myeloperoxidase activity, and mRNA expression of pro-inflammatory interleukin (IL-1α and IL-1β), tumor necrosis factor-alpha (TNF-α) and cannabinoid CB1 and CB2 receptors. JWH015 significantly decreased leukocytes infiltration in both submucosa and mucosa, as well as the myeloperoxydase activity, in LPS treated mice. JWH015 reduced mRNA expression of IL-1α, IL-1β, and TNF-α. LPS treatment increased expression of bladder CB2 but not CB1 mRNA. Taken together, these findings strongly suggest that modulation of the cannabinoid CB2 receptors might be a promising therapeutic strategy for the treatment of bladder diseases and conditions characterized by inflammation, such as interstitial cystitis.

Topics: Animals; Arachidonic Acids; Cannabinoids; Cystitis, Interstitial; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Indoles; Lipopolysaccharides; Male; Mice; Organ Culture Techniques; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2

In our previous studies, we found that a single ultralow dose of tetrahydrocannabinol (THC; 0.002 mg/kg, three to four orders of magnitude lower than the conventional doses) protects the brain from different insults that cause cognitive deficits. Because various insults may trigger a neuroinflammatory response that leads to secondary damage to the brain, the current study tested whether this extremely low dose of THC could protect the brain from inflammation-induced cognitive deficits. Mice received a single injection of THC (0.002 mg/kg) 48 hr before or 1-7 days after treatment with lipopolysccharide (LPS; 10 mg/kg) and were examined with the object recognition test 3 weeks later. LPS caused long-lasting cognitive deficits, whereas the application of THC before or after LPS protected the mice from this LPS-induced damage. The protective effect of THC was blocked by the cannabinoid (CB) 1 receptor antagonist SR14176A but not by the CB2 receptor antagonist SR141528 and was mimicked by the CB1 agonist ACEA but not by the CB2 agonist HU308. The protective effect of THC was also blocked by pretreatment with GW9662, indicating the involvement of peroxisome proliferator-activated receptor-γ. Biochemical examination of the brain revealed a long-term (at least 7 weeks) elevation of the prostaglandin-producing enzyme cyclooxygenase-2 in the hippocampus and in the frontal cortex following the injection of LPS. Pretreatment with the extremely low dose of THC tended to attenuate this elevation. Our results suggest that an ultralow dose of THC that lacks any psychotrophic activity protects the brain from neuroinflammation-induced cognitive damage and might be used as an effective drug for the treatment of neuroinflammatory conditions, including neurodegenerative diseases.

Topics: Anilides; Animals; Arachidonic Acids; Brain; Camphanes; Cannabinoid Receptor Agonists; Cannabinoid Receptor Antagonists; Cognition Disorders; Cyclooxygenase 2; Disease Models, Animal; Dose-Response Relationship, Drug; Dronabinol; Encephalitis; Lipopolysaccharides; Male; Mice; Mice, Inbred ICR; PPAR gamma; Pyrazoles; Recognition, Psychology

The majority of experimental and clinical studies show that ghrelin and cannabinoids are potent inhibitors of epileptic activity in various models of epilepsy. A number of studies have attempted to understand the connection between ghrelin and cannabinoid signalling in the regulation of food intake. Since no data show a functional interaction between ghrelin and cannabinoids in epilepsy, we examined the relationship between these systems via penicillin-induced epileptiform activity in rats. Doses of the CB1 receptor agonist arachidonyl-2-chloroethylamide (ACEA) (2.5 and 7.5 µg), the CB1 receptor antagonist N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3 carboxamide (AM-251) (0.25 and 0.5 µg) and ghrelin (0.5 and 1 µg) were administered intracerebroventricularly (i.c.v.) 30 minutes after the intracortical (i.c.) application of penicillin. In the interaction groups, the animals received either an effective dose of ACEA (7.5 µg, i.c.v.) or a non-effective dose of ACEA (2.5 µg, i.c.v.) or effective doses of AM-251 (0.25, 0.5 µg, i.c.v.) 10 minutes after ghrelin application. A 1 µg dose of ghrelin suppressed penicillin-induced epileptiform activity. The administration of a 0.25 µg dose of AM-251 increased the frequency of penicillin-induced epileptiform activity by producing status epilepticus-like activity. A 7.5 µg dose of ACEA decreased the frequency of epileptiform activity, whereas a non-effective dose of ACEA (2.5 µg) did not change it. Effective doses of AM-251 (0.25, 0.5 µg) reversed the ghrelin's anticonvulsant activity. The application of non-effective doses of ACEA (2.5 µg) together with ghrelin (0.5 µg) within 10 minutes caused anticonvulsant activity, which was reversed by the administration of AM-251 (0.25 µg). The electrophysiological evidence from this study suggests a possible interaction between ghrelin and cannabinoid CB1 receptors in the experimental model of epilepsy.

Topics: Animals; Anticonvulsants; Arachidonic Acids; Cannabinoid Receptor Agonists; Cannabinoid Receptor Antagonists; Cerebral Cortex; Disease Models, Animal; Electroencephalography; Epilepsy; Ghrelin; Infusions, Intraventricular; Male; Penicillins; Piperidines; Pyrazoles; Rats; Rats, Wistar; Receptor, Cannabinoid, CB1

Angiogenesis in liver cirrhosis leads to splanchnic hyperemia, increased portal inflow, and portosystemic collaterals formation, which may induce lethal complications, such as gastroesophageal variceal hemorrhage and hepatic encephalopathy. Cannabinoids (CBs) inhibit angiogenesis, but the relevant influences in cirrhosis are unknown. In this study, Spraque-Dawley rats received common bile duct ligation (BDL) to induce cirrhosis. BDL rats received vehicle, arachidonyl-2-chloroethylamide (cannabinoid receptor type 1 [CB(1) ] agonist), JWH-015 (cannabinoid receptor type 2 [CB(2) ] agonist), and AM630 (CB(2) antagonist) from days 35 to 42 days after BDL. On the 43rd day, hemodynamics, presence of CB receptors, severity of portosystemic shunting, mesenteric vascular density, vascular endothelial growth factor (VEGF), VEGFR-1, VEGFR-2, phospho-VEGFR-2, cyclooxygenase (COX)-1, COX-2, and endothelial nitric oxide synthase (eNOS) expressions as well as plasma VEGF levels were evaluated. Results showed that CB(1) and CB(2) receptors were present in left adrenal veins of sham rats, splenorenal shunts (the most prominent intra-abdominal shunts) of BDL rats, and mesentery of sham and BDL rats. CB(2) receptor was up-regulated in splenorenal shunts of BDL rats. Both acute and chronic JWH-015 treatment reduced portal pressure and superior mesenteric arterial blood flow. Compared with vehicle, JWH-015 significantly alleviated portosystemic shunting and mesenteric vascular density in BDL rats, but not in sham rats. The concomitant use of JWH-015 and AM630 abolished JWH-015 effects. JWH-133, another CB(2) agonist, mimicked the JWH-015 effects. JWH-015 decreased mesenteric COX-1, COX-2 messenger RNA expressions, and COX-1, COX-2, eNOS protein expressions. Furthermore, JWH-015 decreased intrahepatic angiogenesis and fibrosis.. CB(2) agonist alleviates portal hypertension (PH), severity of portosystemic collaterals and mesenteric angiogenesis, intrahepatic angiogenesis, and fibrosis in cirrhotic rats. The mechanism is, at least partly, through COX and NOS down-regulation. CBs may be targeted in the control of PH and portosystemic collaterals.

Topics: Analysis of Variance; Animals; Arachidonic Acids; Collateral Circulation; Common Bile Duct; Disease Models, Animal; Hemodynamics; Hypertension, Portal; Ligation; Liver Cirrhosis; Mesentery; Neovascularization, Pathologic; Random Allocation; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB2; Reference Values; RNA, Messenger; Splanchnic Circulation; Vascular Endothelial Growth Factor A

The present study shows that chronic administration of the cannabinoid receptor type 1 (CB1) receptor agonist arachidonyl-2-chloroethylamide (ACEA) at pre-symptomatic or at early symptomatic stages, at a non-amnesic dose, reduces the cognitive impairment observed in double AβPP(swe)/PS1(1dE9) transgenic mice from 6 months of age onwards. ACEA has no effect on amyloid-β (Aβ) production, aggregation, or clearance. However, ACEA reduces the cytotoxic effect of Aβ42 oligomers in primary cultures of cortical neurons, and reverses Aβ-induced dephosphorylation of glycogen synthase kinase-3β (GSK3β) in vitro and in vivo. Reduced activity of GSK3β in ACEA-treated mice is further supported by the reduced amount of phospho-tau (Thr181) in neuritic processes around Aβ plaques. In addition, ACEA-treated mice show decreased astroglial response in the vicinity of Aβ plaques and decreased expression of the pro-inflammatory cytokine interferon-γ in astrocytes when compared with age-matched vehicle-treated transgenic mice. Our present results show a beneficial effect of ACEA at both the neuronal, mediated at least in part by GSK3β inhibition, and glial levels, resulting in a reduction of reactive astrocytes and lower expression of interferon-γ. As a consequence, targeting the CB1 receptor could offer a versatile approach for the treatment of Alzheimer's disease.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Arachidonic Acids; Astrocytes; Cerebral Cortex; Cognition; Cognition Disorders; Disease Models, Animal; Female; Gliosis; Glycogen Synthase Kinase 3; Glycogen Synthase Kinase 3 beta; Hippocampus; Male; Mice; Mice, Transgenic; Neurons; Neuroprotective Agents; Pregnancy; Presenilin-1; Primary Cell Culture; Receptor, Cannabinoid, CB1

We report on seizures during anesthesia induction in animals treated with a cannabinoid receptor 1 (CB1R) antagonist for experimental sepsis. Animals received surgery for colon ascendens stent peritonitis-induced sepsis or sham surgery followed by treatment of CB1R antagonist, CB1R agonist, or placebo. Fourteen hours later, animals received pentobarbital or ketamine for anesthesia induction and animal behavior was observed. Tonic-clonic seizures were observed in 5 of 12 septic animals (42%) treated with CB1R antagonist after induction of anesthesia with pentobarbital. The data suggest that CB1R inhibition in combination with pentobarbital may increase the incidence of anesthetic-induced seizures in the case of sepsis.

Topics: Anesthesia; Animals; Arachidonic Acids; Behavior, Animal; Disease Models, Animal; Epilepsy, Tonic-Clonic; Hypnotics and Sedatives; Male; Morpholines; Pentobarbital; Pyrazoles; Rats; Rats, Inbred Lew; Receptor, Cannabinoid, CB1; Sepsis; Time Factors

Endogenous cannabinoid ligands and cannabinoid CB1 receptor agonists have been shown to exert anticonvulsant effects in various experimental models of epilepsy. The purpose of this study was to determine the effects of arachidonyl-2'-chloroethylamide (ACEA-a highly selective cannabinoid CB1 receptor agonist) on the protective action of clonazepam, ethosuximide, phenobarbital, and valproate against pentylenetetrazole (PTZ)-induced clonic seizures in mice. To ascertain any pharmacokinetic contribution of ACEA to the observed interactions between tested drugs, free (non-protein bound) plasma and total brain concentrations of the antiepileptic drugs were estimated. Additionally, acute adverse-effect profiles of the combination of ACEA and different classical antiepileptic drugs (clonazepam, ethosuximide, phenobarbital and valproate) with respect to motor performance, long-term memory and skeletal muscular strength were measured. Results indicated that ACEA (10mg/kg, i.p.) co-administered with phenylmethylsulfonyl fluoride (PMSF-a substance protecting ACEA against degradation by the fatty-acid hydrolase; 30mg/kg, i.p.) significantly potentiated the anticonvulsant activity of ethosuximide, phenobarbital and valproate in the mouse PTZ-induced clonic seizure model by reducing their median effective doses (ED(50) values) from 122.8mg/kg to 71.7mg/kg (P<0.01; for ethosuximide), from 13.77mg/kg to 5.26mg/kg (P<0.05; for phenobarbital), and from 142.7mg/kg to 87.3mg/kg (P<0.05; for valproate), respectively. In contrast, ACEA (10mg/kg, i.p.) in combination with PMSF (30mg/kg, i.p.) had no impact on the protective action of clonazepam against PTZ-induced seizures in mice. However, ACEA (10mg/kg)+PMSF (30mg/kg) considerably increased free plasma and total brain concentrations of ethosuximide and valproate in mice suggesting a pharmacokinetic nature of interaction between drugs. In contrast, free plasma and total brain concentrations of clonazepam and phenobarbital remained unchanged after ACEA+PMSF administration and thus, indicating pharmacodynamic interactions. Moreover, none of the examined combinations of ACEA (10mg/kg, i.p.)+PMSF (30mg/kg, i.p.) with clonazepam, ethosuximide, phenobarbital, and valproate (at their ED(50) values from the PTZ-induced seizure test) affected motor coordination in the chimney test, long-term memory in the passive avoidance task, and muscular strength in the grip-strength test in mice, indicating no possible acute adverse effects in anim

Topics: Animals; Anticonvulsants; Arachidonic Acids; Avoidance Learning; Cannabinoid Receptor Agonists; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Synergism; Drug Therapy, Combination; Hand Strength; Male; Mice; Motor Activity; Pentylenetetrazole; Phenylmethylsulfonyl Fluoride; Seizures

We investigated the effects of cannabinoid receptor agonists on (1) oral cancer cell viability in vitro and (2) oral cancer pain and tumor growth in a mouse cancer model. We utilized immunohistochemistry and Western blot to show that human oral cancer cells express CBr1 and CBr2. When treated with WIN55,212-2 (non-selective), ACEA (CBr1-selective) or AM1241 (CBr2-selective) agonists in vitro, oral cancer cell proliferation was significantly attenuated in a dose-dependent manner. In vivo, systemic administration (0.013M) of WIN55,212-2, ACEA, or AM1241 significantly attenuated cancer-induced mechanical allodynia. Tumor growth was also significantly attenuated with systemic AM1241 administration. Our findings suggest a direct role for cannabinoid mechanisms in oral cancer pain and proliferation. The systemic administration of cannabinoid receptor agonists may have important therapeutic implications wherein cannabinoid receptor agonists may reduce morbidity and mortality of oral cancer.

Topics: Analgesics; Animals; Arachidonic Acids; Benzoxazines; Blotting, Western; Cannabinoids; Cell Line, Tumor; Cell Proliferation; Disease Models, Animal; Female; Fluorescent Antibody Technique; Humans; Hyperalgesia; Immunohistochemistry; Mice; Mice, Nude; Morpholines; Mouth Neoplasms; Naphthalenes; Pain; Receptors, Cannabinoid

The aim of this study was to determine the influence of arachidonyl-2'-chloroethylamide (ACEA - a highly selective cannabinoid type 1 [CB1] receptor agonist) on the protective action and acute adverse effects of carbamazepine, lamotrigine, oxcarbazepine, phenobarbital, phenytoin, and topiramate in the maximal electroshock seizure model and chimney test in mice. Tonic hind limb extension (seizure activity) was evoked in adult male albino Swiss mice by a current (sine-wave, 25 mA, 500 V, 50 Hz, 0.2s stimulus duration) delivered via auricular electrodes. Acute adverse-effect profiles of the studied antiepileptic drugs with respect to motor coordination was assessed in the chimney test. Additionally, long-term memory and skeletal muscular strength were measured along with free plasma (non-protein bound) and total brain antiepileptic drug concentrations. To inhibit the rapid metabolic degradation of ACEA by the fatty-acid amide hydrolase, phenylmethylsulfonyl fluoride (PMSF) was used at a constant ineffective dose of 30 mg/kg. Results indicate that ACEA (2.5 mg/kg, i.p.) co-administered with PMSF (30 mg/kg, i.p.), significantly enhanced the anticonvulsant activity of phenobarbital, but not that of carbamazepine, lamotrigine, oxcarbazepine, phenytoin, or topiramate in the maximal electroshock seizure test in mice. Moreover, ACEA (2.5 mg/kg) with PMSF (30 mg/kg) had no significant impact on the acute adverse effects of all examined antiepileptic drugs in the chimney test in mice. The protective index values (as quotients of the respective TD(50) and ED(50) values denoted from the chimney and maximal electroshock seizure tests, respectively) for the combinations of ACEA (2.5 mg/kg) and PMSF (30 mg/kg) with carbamazepine, oxcarbazepine, phenobarbital, and topiramate were greater than those denoted for the antiepileptic drugs administered alone. Only, the protective index values for the combination of ACEA (2.5 mg/kg) and PMSF (30 mg/kg) with lamotrigine and phenytoin were lower than those determined for the antiepileptic drugs administered alone. Pharmacokinetic experiments revealed that ACEA (2.5 mg/kg) and PMSF (30 mg/kg) affected neither free plasma (non-protein bound) nor total brain concentrations of phenobarbital in mice. Moreover, ACEA and PMSF in combination with carbamazepine, lamotrigine, oxcarbazepine, phenobarbital, phenytoin, and topiramate did not alter long-term memory or skeletal muscular strength in experimental animals. In conclusion, the enhance

Topics: Animals; Anticonvulsants; Arachidonic Acids; Avoidance Learning; Disease Models, Animal; Drug Combinations; Electroshock; Enzyme Inhibitors; Male; Memory Disorders; Mice; Muscle Strength; Muscle, Skeletal; Phenylmethylsulfonyl Fluoride; Psychomotor Performance; Receptor, Cannabinoid, CB1; Seizures

Cannabinoid agonists might serve as neuroprotective agents in neurodegenerative disorders. Here, we examined this hypothesis in a rat model of Huntington's disease (HD) generated by intrastriatal injection of the mitochondrial complex II inhibitor malonate. Our results showed that only compounds able to activate CB2 receptors were capable of protecting striatal projection neurons from malonate-induced death. That CB2 receptor agonists are neuroprotective was confirmed by using the selective CB2 receptor antagonist, SR144528, and by the observation that mice deficient in CB2 receptor were more sensitive to malonate than wild-type animals. CB2 receptors are scarce in the striatum in healthy conditions, but they are markedly upregulated after the lesion with malonate. Studies of double immunostaining revealed a significant presence of CB2 receptors in cells labeled with the marker of reactive microglia OX-42, and also in cells labeled with GFAP (a marker of astrocytes). We further showed that the activation of CB2 receptors significantly reduced the levels of tumor necrosis factor-alpha (TNF-alpha) that had been increased by the lesion with malonate. In summary, our results demonstrate that stimulation of CB2 receptors protect the striatum against malonate toxicity, likely through a mechanism involving glial cells, in particular reactive microglial cells in which CB2 receptors would be upregulated in response to the lesion. Activation of these receptors would reduce the generation of proinflammatory molecules like TNF-alpha. Altogether, our results support the hypothesis that CB2 receptors could constitute a therapeutic target to slowdown neurodegeneration in HD.

Topics: Animals; Arachidonic Acids; Camphanes; Cannabinoids; Cell Death; Central Nervous System Agents; Corpus Striatum; Disease Models, Animal; Huntington Disease; Male; Malonates; Mice; Mice, Knockout; Neuroglia; Neurons; Neuroprotective Agents; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptor, Cannabinoid, CB2; Tumor Necrosis Factor-alpha

Cannabinoid system plays a pivotal role in the seizure threshold modulation which is mainly mediated through activation of the cannabinoid CB(1) receptor. There is also several evidence of interaction between cannabinoid system and other neurotransmitters including nitric oxide (NO) system. Using model of clonic seizure induced by pentylenetetrazole (PTZ) in male NMRI mice, we investigated whether NO is involved in the effects of cannabinoids on the seizure threshold. Injection of the selective cannabinoid CB(1) agonist ACEA (2mg/kg, i.p.) significantly (P<0.01) increased the seizure threshold which was prevented (P<0.001) by pretreatment with the selective CB(1) antagonist AM251 (1mg/kg, i.p.). The NO precursor l-arginine (50 and 100mg/kg, i.p.) potentiated the anticonvulsant effects of the sub-effective dose of ACEA (1mg/kg, i.p.). Pretreatment with non-effective doses of the non-specific NOS inhibitor l-NAME (15 and 30mg/kg, i.p.) and the specific neuronal NOS inhibitor 7-NI (40 and 80mg/kg, i.p.) but not the inducible NOS inhibitor aminoguanidine (10, 50 and 100mg/kg, i.p.) prevented the anticonvulsant effect of ACEA (2mg/kg, i.p.). Co-administration of non-effective dose of AM251 (0.5mg/kg) with both low and per se non-effective doses of l-NAME (1mg/kg, i.p.) and 7-NI (10mg/kg, i.p.) had significant (P<0.01) effect in preventing the anticonvulsant effect of ACEA (2mg/kg, i.p.). Our findings demonstrated that central NO system could be involved in the anticonvulsant properties of the specific cannabinoid CB(1) agonist ACEA, emphasizing on the interaction between two systems in the seizure modulation.

Topics: Analysis of Variance; Animals; Animals, Inbred Strains; Anticonvulsants; Arachidonic Acids; Arginine; Brain; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Interactions; Enzyme Inhibitors; Male; Mice; NG-Nitroarginine Methyl Ester; Nitric Oxide; Pentylenetetrazole; Piperidines; Pyrazoles; Receptor, Cannabinoid, CB1; Seizures

Several results support the conclusion that the cannabinoid system has a role in generation and cessation of epileptic seizures. The aim of this study was to evaluate the effects of intracerebroventricular AM-251 [N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide], a CB1-receptor antagonist, and ACEA (arachidonyl-2-chloroethylamide), a CB1-receptor agonist, on penicillin-induced epileptiform activity in rats.. In the first set of experiments, 30 min after penicillin injection, AM-251, at doses of 0.125, 0.25, 0.5, and 1 μg, was administered intracerebroventricularly (i.c.v.). In the second set of experiments, 30 min after penicillin injection, ACEA, at doses of 2.5, 5, 7.5, and 15 μg (i.c.v.), was administered. In the third set of experiments, AM-251, at doses of 0.125 and 0.25 μg (i.c.v.), was administered 10 min before ACEA (7.5 μg, i.c.v.) injection.. ACEA, at a dose of 7.5 μg, significantly decreased the frequency of penicillin-induced epileptiform activity without changing the amplitude. ACEA, at doses of 2.5, 5, and 15 μg, had no impact on either frequency or amplitude of epileptiform activity. AM-251, at doses of 0.25 and 0.50 μg, significantly increased the frequency of epileptiform activity. AM-251, at a dose of 0.25 μg (i.c.v.), was the most effective in changing the frequency of penicillin-induced epileptiform activity, and it also caused status epilepticus-like activity. AM-251, at doses of 0.125 and 0.25 μg, 10 min before ACEA (7.5 μg), reversed the anticonvulsant action of ACEA.. The results of the present study provide electrophysiologic evidence for the role of CB1 receptors in regulating the frequency of epileptiform activity in the model of penicillin-induced epilepsy. To elucidate the precise mechanism of cannabinoid action in the brain during seizure, more advanced electrophysiologic and neurochemical studies are required.

Topics: Animals; Anticonvulsants; Arachidonic Acids; Brain; Cannabinoids; Cerebral Cortex; Disease Models, Animal; Dose-Response Relationship, Drug; Electroencephalography; Epilepsy; Injections, Intraventricular; Male; Penicillins; Piperidines; Pyrazoles; Rats; Receptor, Cannabinoid, CB1; Seizures

Bone cancer pain has a strong impact on the quality of life of patients, but it is difficult to treat. Therefore, development of a novel strategy for the treatment of bone cancer pain is needed for improvement of patient quality of life. This study examined whether selective spinal cannabinoid receptor 1 (CB1) activation alleviates bone cancer pain and also examined the spinal expression of CB1.. A bone cancer pain model was made by implantation of sarcoma cells into the intramedullary space of the mouse femur. In behavioral experiments, the authors examined the effects of activation of spinal CB1 and inhibition of metabolism of endocannabinoid on bone cancer-related pain behaviors. Immunohistochemical experiments examined the distribution and localization of CB1 in the superficial dorsal horn of the spinal cord using specific antibodies.. Spinal CB1 activation by exogenous administration of a CB1 agonist arachidonyl-2-chloroethylamide reduced bone cancer-related pain behaviors, including behaviors related to spontaneous pain and movement-evoked pain. In immunohistochemical experiments, although mu-opioid receptor 1 expression was reduced in the superficial dorsal horn ipsilateral to the site of implantation of sarcoma cells, CB1 expression was preserved. In addition, CB1 was mainly expressed in the axon terminals, but not in the dendritic process in the superficial dorsal horn.. Spinal CB1 activation reduced bone cancer-related pain behavior. Presynaptic inhibition may contribute to the analgesic effects of spinal CB1 activation. These findings may lead to novel strategies for the treatment of bone cancer pain.

Topics: Analgesics; Animals; Arachidonic Acids; Bone Neoplasms; Disease Models, Animal; Gene Expression Regulation, Neoplastic; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Pain; Pain Measurement; Posterior Horn Cells; Receptor, Cannabinoid, CB1

Contradictory results exist concerning the effects of systemic injections of CB(1) cannabinoid receptor agonists on anxiety-related behaviors. Direct drug administration into brain structures related to aversive responses can potentially help to clarify the role of cannabinoids on anxiety. One such structure is the midbrain dorsolateral periaqueductal gray (dlPAG). Therefore, the aim of this study was to test the hypothesis that the activation of the CB(1) receptor in the dlPAG would attenuate anxiety-related behaviors. Male Wistar rats with cannula aimed at the dlPAG received injections of the endogenous cannabinoid anandamide, the anandamide transport inhibitor AM404, the anandamide analogue ACEA or the CB(1) receptor antagonist AM251, and were submitted to the elevated plus maze (EPM), an animal model of anxiety. Anandamide (0.5-50pmol) and ACEA (0.05-5pmol) induced anxiolytic-like effects with bell-shaped dose-response curves, the higher doses being ineffective. The anandamide anxiolytic effect was potentiated by AM404 (50pmol) and prevented by AM251 (100pmol). Neither AM404 (0.5-50pmol) nor AM251 (1-100pmol) alone modified the animal behavior in the EPM. The present study suggests that the dlPAG is a possible neuroanatomical site for anxiolytic-like effects mediated by CB(1) agonists. Furthermore, this work supports the importance of neuronal uptake as a mechanism that limits the in vivo actions of anandamide.

Topics: Animals; Anxiety; Arachidonic Acids; Behavior, Animal; Cannabinoids; Disease Models, Animal; Dose-Response Relationship, Drug; Endocannabinoids; Male; Maze Learning; Periaqueductal Gray; Piperidines; Polyunsaturated Alkamides; Pyrazoles; Rats; Rats, Wistar; Receptor, Cannabinoid, CB1

We have recently demonstrated that two plant-derived cannabinoids, Delta9-tetrahydrocannabinol and cannabidiol (CBD), are neuroprotective in an animal model of Parkinson's disease (PD), presumably because of their antioxidant properties. To further explore this issue, we examined the neuroprotective effects of a series of cannabinoid-based compounds, with more selectivity for different elements of the cannabinoid signalling system, in rats with unilateral lesions of nigrostriatal dopaminergic neurons caused by local application of 6-hydroxydopamine. We used the CB1 receptor agonist arachidonyl-2-chloroethylamide (ACEA), the CB2 receptor agonist HU-308, the non-selective agonist WIN55,212-2, and the inhibitors of the endocannabinoid inactivation AM404 and UCM707, all of them administered i.p. Daily administration of ACEA or WIN55,212-2 did not reverse 6-hydroxydopamine-induced dopamine (DA) depletion in the lesioned side, whereas HU-308 produced a small recovery that supports a possible involvement of CB2 but not CB1 receptors. AM404 produced a marked recovery of 6-hydroxydopamine-induced DA depletion and tyrosine hydroxylase deficit in the lesioned side. Possibly, this is caused by the antioxidant properties of AM404, which are derived from the presence of a phenolic group in its structure, rather than by the capability of AM404 to block the endocannabinoid transporter, because UCM707, another transporter inhibitor devoid of antioxidant properties, did not produce the same effect. None of these effects were observed in non-lesioned contralateral structures. We also examined the timing for the effect of CBD to provide neuroprotection in this rat model of PD. We found that CBD, as expected, was able to recover 6-hydroxydopamine-induced DA depletion when it was administered immediately after the lesion, but it failed to do that when the treatment started 1 week later. In addition, the effect of CBD implied an upregulation of mRNA levels for Cu,Zn-superoxide dismutase, a key enzyme in endogenous defenses against oxidative stress. In summary, our results indicate that those cannabinoids having antioxidant cannabinoid receptor-independent properties provide neuroprotection against the progressive degeneration of nigrostriatal dopaminergic neurons occurring in PD. In addition, the activation of CB2 (but not CB1) receptors, or other additional mechanisms, might also contribute to some extent to the potential of cannabinoids in this disease.

Topics: Animals; Antioxidants; Arachidonic Acids; Benzoxazines; Cannabinoid Receptor Agonists; Cannabinoid Receptor Antagonists; Cannabinoids; Disease Models, Animal; Dopamine; Furans; Male; Morpholines; Naphthalenes; Nerve Degeneration; Neuroprotective Agents; Organ Culture Techniques; Oxidative Stress; Oxidopamine; Parkinsonian Disorders; Polyunsaturated Alkamides; Rats; Rats, Sprague-Dawley; Receptors, Cannabinoid; Superoxide Dismutase; Sympatholytics

Several lines of evidence suggest that cannabinoid compounds are anticonvulsant since they have inhibitory effects at micromolar doses, which are mediated by activated receptors coupling to Gi/o proteins. Surprisingly, both the analgesic and anticonvulsant effects of opioids are enhanced by ultra-low doses (nanomolar to picomolar) of the opioid antagonist naltrexone and as opioid and cannabinoid systems interact, it has been shown that ultra-low dose naltrexone also enhances cannabinoid-induced antinociception. However, regarding the seizure modulating properties of both classes of receptors this study investigated whether ultra-low dose cannabinoid antagonist AM251 influences cannabinoid anticonvulsant effects. The clonic seizure threshold (CST) was tested in separate groups of male NMRI mice following injection of vehicle, the cannabinoid selective agonist arachidonyl-2-chloroethylamide (ACEA) and ultra-low doses of the cannabinoid CB1 antagonist AM251 and a combination of ACEA and AM251 doses in a model of clonic seizure induced by pentylenetetrazole (PTZ). Systemic administration of ultra-low doses of AM251 (10 fg/kg-100 ng/kg) significantly potentiated the anticonvulsant effect of ACEA at 0.5 and 1 mg/kg. Moreover, inhibition of cannabinoid induced excitatory signaling by AM251 (100 pg/kg) unmasked a strong anticonvulsant effect for very low doses of ACEA (100 ng/kg-100 microg/kg), suggesting that a presumed inhibitory component of cannabinoid receptor signaling can exert strong seizure-protective effects even at very low levels of cannabinoid receptor activation. A similar potentiation by AM251 (100 pg/kg and 1 ng/kg) of anticonvulsant effects of non-effective dose of ACEA (0.5 and 1 mg/kg) was also observed in the generalized tonic-clonic model of seizure. The present data suggest that ultra-low doses of cannabinoid receptor antagonists may provide a potent strategy to modulate seizure susceptibility, especially in conjunction with very low doses of cannabinoids.

Topics: Animals; Anticonvulsants; Arachidonic Acids; Cannabinoid Receptor Agonists; Cannabinoid Receptor Antagonists; Convulsants; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Synergism; Male; Mice; Pentylenetetrazole; Piperidines; Pyrazoles; Seizures

Oil of mustard (OM) is a potent neuronal activator that is known to elicit visceral hyperalgesia when given intracolonically, but the full extent to which OM is also proinflammatory in the gastrointestinal tract is not known. We have previously shown that male CD-1 mice given a single administration of 0.5% OM develop a severe colitis that is maximum at day 3 and that gradually lessens until essentially absent by day 14. OM-induced neuronal stimulation is reported to be reduced by cannabinoid agonists, and cannabinoid receptor 1 (CB1R)-/- mice have exacerbated experimental colitis. Therefore, we examined the role of cannabinoids in this OM-induced 3-day model of colitis in CD-1 mice and in a 7-day dextran sulfate sodium (DSS) colitis model in BALB/c mice. In OM colitis, the CB1R-selective agonist ACEA and the CB2R-selective agonist JWH-133 reduced (P < 0.05) colon weight gain (means +/- SE; 82 +/- 13% and 47 +/- 15% inhibition, respectively), colon shrinkage (98 +/- 24% and 42 +/- 12%, respectively), colon inflammatory damage score (49 +/- 11% and 40 +/- 12%, respectively), and diarrhea (58 +/- 12% and 43 +/- 11%, respectively). Histological damage was similarly reduced by these treatments. Likewise, CBR agonists attenuated DSS colitis, albeit at higher doses; ACEA at 10 mg/kg, twice daily, inhibited (P < 0.05) macroscopic and microscopic scores (46 +/- 9% and 63 +/- 7%, respectively); whereas 20 mg/kg, twice daily, of JWH-133 was required to diminish (P < 0.05) macroscopic and microscopic scores (29 +/- 7% and 43 +/- 5%, respectively). CB1R and CB2R immunostaining of colon sections revealed that CB1R in enteric neurons was more intense in colitic vs. control mice; however, CB1R was also increased in the endothelial layer in OM colitis only. CB2R immunostaining was more marked in infiltrated immune cells in OM colitis. These findings validate the OM colitis model with respect to the DSS model and provide strong support to the emerging idea that cannabinoid receptor activation mediates protective mechanisms in experimental colitis. The demonstration of CB1R agonist effects in colitis support the neurogenic nature of the OM-induced colitis model and reinforce the importance of neuronal activation in intestinal inflammation.

Topics: Animals; Arachidonic Acids; Cannabinoids; Colitis; Dextran Sulfate; Disease Models, Animal; Male; Mice; Mice, Inbred BALB C; Mustard Plant; Plant Oils; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Treatment Outcome

Brain slices from 7-d-old Wistar rats were exposed to oxygen-glucose deprivation (OGD) for 30 min. OGD slices were incubated with vehicle or with the CB1/CB2 cannabinoid agonist WIN55212 (50 microM), the CB1 agonist arachidonyl-2-chloroethylamide (ACEA) (50 microM), or the CB2 agonist JW133 (50 microM), alone or combined with the CB1 and CB2 receptor antagonist SR 141716 (50 microM) or SR 144528 (50 microM), respectively. Neuronal damage was assessed by histologic analysis and spectrophotometric determination of lactate dehydrogenase (LDH) efflux into the incubation medium. Additionally, medium glutamate levels were determined by high-performance liquid chromatography (HPLC) and those of tumor necrosis factor alpha (TNF-alpha) by enzyme-linked immunosorbent assay. Finally, inducible nitric oxide synthase (iNOS) and CB1/CB2 receptor expression were determined in slices homogenate by Western blot. Both CB1 and CB2 receptors were expressed in slices. OGD increased CB1 expression, cellular damage, LDH efflux, glutamate and TNF-alpha release, and inducible nitric oxide synthase (iNOS) expression; WIN55212 inhibited all these actions. SR141716 and SR144528 inhibited the effect of R(+)-WIN-55212-2 (WIN), as well as the reduction of LDH efflux by ACEA and JW133, respectively. In conclusion, WIN55212 afforded robust neuroprotection in the forebrain slices exposed to OGD, by acting on glutamatergic excitotoxicity, TNF-alpha release, and iNOS expression; this neuroprotective effect seemed to be mediated by CB1 and CB2 receptors.

Topics: Anaerobiosis; Animals; Animals, Newborn; Arachidonic Acids; Benzoxazines; Brain; Brain Chemistry; Brain Ischemia; Cannabinoid Receptor Agonists; Cannabinoids; Disease Models, Animal; Hypoxia, Brain; L-Lactate Dehydrogenase; Morpholines; Naphthalenes; Neuroprotective Agents; Nitric Oxide Synthase Type II; Piperidines; Pyrazoles; Rats; Rats, Wistar; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Rimonabant; Tumor Necrosis Factor-alpha

Endogenous cannabinoid ligands and cannabinoid CB(1) receptor agonists have been shown to exert potent anticonvulsant effects in various experimental models of epilepsy. The purpose of this study was to determine the effects of arachidonyl-2'-chloroethylamide (ACEA; N-(2-chloroethyl)-5Z,8Z,11Z,14Z-eicosatetraenamide, a highly selective cannabinoid CB(1) receptor agonist) on the threshold for electroconvulsions and the anticonvulsant activity of valproate in the maximal electroshock-induced seizures in mice. To inhibit the rapid metabolic degradation of ACEA by the fatty-acid amide hydrolase, phenylmethylsulfonyl fluoride (PMSF) was used at a constant ineffective dose of 30 mg/kg (i.p.). Moreover, the effects of ACEA and PMSF on the acute adverse-effect profile of valproate were determined in the chimney test. Additionally, the adverse-effect potentials of combination of ACEA, PMSF with valproate were examined in the step-through passive avoidance task (long-term memory) and grip-strength test (neuromuscular strength). To ascertain any pharmacokinetic contribution of ACEA and PMSF to the observed interaction between tested drugs, both free (non-protein bound) plasma and total brain concentrations of valproate were estimated. Results indicated that ACEA (5 and 7.5 mg/kg; i.p.) combined with PMSF increased significantly (P<0.001) the electroconvulsive threshold in mice. ACEA at low doses of 1.25 and 2.5 mg/kg, i.p., with PMSF had no impact on threshold for electroconvulsions. Similarly, neither PMSF (30 mg/kg) nor ACEA (15 mg/kg) administered alone affected the electroconvulsive threshold in mice. Moreover, ACEA (at a subthreshold dose of 2.5 mg/kg; i.p.) co-administered with PMSF potentiated significantly the antielectroshock activity of valproate by reducing its ED(50) from 258.3 to 195.1 mg/kg (P<0.01). Isobolographic transformation of data revealed that the interactions between valproate and ACEA (at 1.25 and 2.5 mg/kg) combined with PMSF were additive. In the chimney test, the combination of ACEA (2.5 mg/kg) and PMSF (30 mg/kg) had no effect on acute adverse effect of valproate and its TD(50) (356.4 mg/kg) did not differ significantly from that for valproate administered alone (TD(50)=404.4 mg/kg). Moreover, none of the examined drugs administered either alone or in combinations produced long-term memory deficits in the step-through passive avoidance task and impaired neuromuscular strength in the grip-strength test in mice. In contrast, ACEA (2.5 mg/kg

Topics: Amidohydrolases; Animals; Anticonvulsants; Arachidonic Acids; Avoidance Learning; Brain; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Synergism; Electroshock; Enzyme Inhibitors; Forelimb; Male; Memory; Mice; Molecular Structure; Muscles; Phenylmethylsulfonyl Fluoride; Receptor, Cannabinoid, CB1; Seizures; Time Factors; Valproic Acid