piperidines and oleylamide

The endocannabinoid system has been associated with antiproliferative effects in several types of tumors through cannabinoid receptor-mediated cell death mechanisms. Oleamide (ODA) is a CB1/CB2 agonist associated with cell growth and migration by adhesion and/or ionic signals associated with Gap junctions. Antiproliferative mechanisms related to ODA remain unknown. In this work, we evaluated the effects of ODA on cell viability and morphological changes in a rat RG2 glioblastoma cell line and compared these effects with primary astrocyte cultures from 8-day postnatal rats. RG2 and primary astrocyte cultures were treated with ODA at increasing concentrations (25, 50, 100, and 200 μM) for different periods of time (12, 24, and 48 h). Changes in RG2 cell viability and morphology induced by ODA were assessed by viability/mitochondrial activity test and phase contrast microscopy, respectively. The ratios of necrotic and apoptotic cell death, and cell cycle alterations, were evaluated by flow cytometry. The roles of CB1 and CB2 receptors on ODA-induced changes were explored with specific receptor antagonists. ODA (100 μM) induced somatic damage, detachment of somatic bodies, cytoplasmic polarization, and somatic shrinkage in RG2 cells at 24 and 48 h. In contrast, primary astrocytes treated at the same ODA concentrations exhibited cell aggregation but not cell damage. ODA (100 μM) increased apoptotic cell death and cell arrest in the G1 phase at 24 h in the RG2 line. The effects induced by ODA on cell viability of RG2 cells were independent of CB1 and CB2 receptors or changes in intracellular calcium transient. Results of this novel study suggest that ODA exerts specific antiproliferative effects on RG2 glioblastoma cells through unconventional apoptotic mechanisms not involving canonical signals.

Topics: Animals; Cell Death; Cell Line, Tumor; Cell Survival; Dose-Response Relationship, Drug; Glioblastoma; Hypnotics and Sedatives; Oleic Acids; Piperidines; Pyrazoles; Rats; Rats, Inbred F344; Rats, Wistar; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2

In this study, we have pursued to assess oleamide's potential role in reward and aversion mechanisms. To reach this goal we infused oleamide, either 1 μg into the nucleus accumbens shell (NAccS) and evaluated its effects on conditioned place preference (CCP) or 10 μg, to evaluate conditioned place aversion (CPA). Extinction and reinstatement were also evaluated in both cases. We sought to determine if CPP occurs via cannabinoid receptor 1 (CB1R) and CPA via serontoninergic 2c receptor (5HT2cR). Results revealed that 1 μg of oleamide administered bilaterally into the NAccS induced CPP, while 10 μg induced CPA. In both conditions CPP or CPA, reinstatement after extinction was induced. AM251 (CB1R inverse-agonist) prevented CPP induced with 1 μg; while SB242084 (5HT2cR antagonist) not only prevented CPA induced with 10 μg but caused a switch to CPP. These results suggest that oleamide at low doses promotes reward through CB1R, and aversion at high doses via 5HT2cR.

Topics: Aminopyridines; Animals; Conditioning, Operant; Extinction, Psychological; Indoles; Male; Nucleus Accumbens; Oleic Acids; Piperidines; Pyrazoles; Rats; Rats, Wistar; Receptor, Cannabinoid, CB1; Receptor, Serotonin, 5-HT2C; Reward; Serotonin 5-HT2 Receptor Antagonists

The forced swim test and the tail suspension test in mice were used to determine the antidepressant-like activity.. Concomitant intraperitoneal administration of per se inactive doses of oleamide (5 mg/kg) or AM251 (0.25 mg/kg) and the tested biometals (i.e. magnesium, 10 mg/kg or zinc, 5 mg/kg) shortened the immobility time of animals in the forced swim test and the tail suspension test. The observed effect was not associated with an increase in spontaneous locomotor activity of mice.. The simultaneous modulation of the cannabinoid system and supplementation of magnesium or zinc produce at least additive antidepressant-like effect.

Topics: Animals; Antidepressive Agents; Behavior Rating Scale; Depression; Drug Synergism; Hypnotics and Sedatives; Ligands; Magnesium; Male; Mice; Motor Activity; Oleic Acids; Piperidines; Pyrazoles; Receptor, Cannabinoid, CB1; Swimming; Trace Elements; Zinc

The endocannabinoid system, through the cannabinoid type 1 (CB1) and 2 (CB2) receptors modulates many physiological functions, including different aspects of memory-related processes. The aim of the present experiments was to explore the role of the endocannabinoid system, through CB1 receptors in the different stages of short-term (acquisition, retention and retrieval) and long-term (acquisition, consolidation and retrieval) memory-related responses, using the inhibitory avoidance (IA) test in mice. Our results revealed that an acute injection of oleamide (10 and 20mg/kg), a CB1 receptor agonist, impairs the short-term or/and long-term acquisition, retention/consolidation, retrieval memory and learning processes in the IA test in mice. In turn, in this test an acute injection of AM 251 (1 and 3mg/kg), a CB1 receptor antagonist, improves the short-term or/and long-term memory stages, described above. Moreover, this memory impairment induced by effective dose of oleamide (20mg/kg) is reversed by non-effective dose of AM 251 (0.25mg/kg) in the IA task, which proves the selectivity of oleamide to CB1 receptors and confirms that the CB1 receptor-related mechanism is one of the possible mechanisms, responsible for memory and learning responses. Obtained results provide clear evidence that the endocannabinoid system, through CB1 receptors, participates in the different stages of short- and long-term memory-related behavior. This knowledge may open in the future new possibilities for the development of CB-based therapies, especially for memory impairment human disorders.

Topics: Animals; Avoidance Learning; Cannabinoid Receptor Agonists; Cannabinoid Receptor Antagonists; Dose-Response Relationship, Drug; Inhibition, Psychological; Male; Memory; Mice; Motor Activity; Neuropsychological Tests; Oleic Acids; Piperidines; Pyrazoles; Receptor, Cannabinoid, CB1

A growing body of psychiatric research has emerged, focusing on the role of endocannabinoid system in psychiatric disorders. For example, the endocannabinoid system, via cannabinoid CB (CB1 and CB2) receptors, is able to control the function of many receptors, such as N-methyl-D-aspartate (NMDA) receptors connected strictly with psychosis or other schizophrenia-associated symptoms. The aim of the present research was to investigate the impact of the CB1 receptor ligands on the symptoms typical for schizophrenia. We provoked psychosis-like effects in mice by an acute administration of NMDA receptor antagonist, MK-801 (0.1-0.6 mg/kg). An acute administration of MK-801 induced psychotic symptoms, manifested in the increase in locomotor activity (hyperactivity), measured in actimeters, as well as the memory impairment, assessed in the passive avoidance task. We revealed that an acute injection of CB1 receptor agonist, oleamide (5-20 mg/kg), had no influence on the short- and long-term memory-related disturbances, as well as on the hyperlocomotion in mice, provoking by an acute MK-801. In turn, an amnestic effects or hyperactivity induced by an acute MK-801 was attenuated by an acute administration of AM 251 (0.25-3 mg/kg), a CB1 receptor antagonist. The present findings confirm that endocannabinoid system is able to modify a variety of schizophrenia-like responses, including the cognitive disturbances and hyperlocomotion in mice. Antipsychotic-like effects induced by CB1 receptor antagonist, obtained in our research, confirm the potential effect of CB1 receptor blockade and could have important therapeutic implications on clinical settings, in the future.

Topics: Animals; Antipsychotic Agents; Cannabinoid Receptor Modulators; Disease Models, Animal; Dizocilpine Maleate; Dose-Response Relationship, Drug; Endocannabinoids; Excitatory Amino Acid Antagonists; Male; Memory Disorders; Memory, Long-Term; Memory, Short-Term; Mice; Motor Activity; Oleic Acids; Piperidines; Pyrazoles; Receptor, Cannabinoid, CB1; Schizophrenia; Schizophrenic Psychology

The purpose of the experiments was to explore the role of the endocannabinoid system, through cannabinoid (CB) receptor ligands, nicotine and scopolamine, in the depression-related responses using the forced swimming test (FST) in mice. Our results revealed that acute injection of oleamide (10 and 20 mg/kg), a CB1 receptor agonist, caused antidepressant-like effect in the FST, while AM 251 (0.25-3 mg/kg), a CB1 receptor antagonist, did not provoke any effect in this test. Moreover, acute administration of both CB2 receptor agonist, JWH 133 (0.5 and 1 mg/kg) and CB2 receptor antagonist, AM 630 (0.5 mg/kg), exhibited antidepressant action. Antidepressant effects of oleamide and JWH 133 were attenuated by acute injection of both non-effective dose of AM 251, as well as AM 630. Among the all CB compounds used, only the combination of non-effective dose of oleamide (2.5 mg/kg) with non-effective dose of nicotine (0.5 mg/kg) caused an antidepressant effect. However, none of the CB receptor ligands, had influence on the antidepressant effects provoked by nicotine (0.2 mg/kg) injection. In turn, the combination of non-effective dose of oleamide (2.5 mg/kg); JWH (2 mg/kg) or AM 630 (2 mg/kg), but not of AM 251 (0.25 mg/kg), with non-effective dose of scopolamine (0.1 mg/kg), exhibited antidepressant properties. Indeed, all of the CB compounds used, intensified the antidepressant-like effects induced by an acute injection of scopolamine (0.3 mg/kg). Our results provide clear evidence that the endocannabinoid system participates in the depression-related behavior and through interactions with cholinergic system modulate these kind of responses.

Topics: Animals; Antidepressive Agents; Cannabinoids; Depressive Disorder; Disease Models, Animal; Indoles; Ligands; Male; Mice; Motor Activity; Nicotine; Oleic Acids; Piperidines; Pyrazoles; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Scopolamine; Swimming

Endocannabinoids (eCBs) are mediators of the homeostatic and hedonic systems that modulate food ingestion. Hence, eCBs, by regulating the hedonic system, may be modulating the valence of the emotion associated to food ingestion (positive: pleasant or negative: unpleasant). Our first goal was to demonstrate that palatable food induces conditioned place preference (CPP), hence a positive-valence emotion. Additionally, we analyzed if this CPP is blocked by AM251, inducing a negative valence emotion, meaning avoiding the otherwise pursued compartment. The second goal was to demonstrate that CPP induced by regular food would be strengthened by the simultaneous administration of anandamide or oleamide, and if such, CPP is blocked by AM251. Finally, we tested the capacity of eCBs (without food) to induce CPP. Our results indicate that rats readily developed CPP to palatable food, which was blocked by AM251. The CPP induced by regular food was strengthened by eCBs and blocked by AM251. Finally, oleamide, unlike anandamide, induced CPP. These results showed that eCBs mediate the positive valence (CPP) of the emotion associated to food ingestion. It was also observed that the blockade of the CB1 receptor causes a loss of correlation between food and CPP (negative valence: avoidance). These data further support the role of eCBs as regulators of the hedonic value of food.

Topics: Animals; Arachidonic Acids; Cannabinoid Receptor Modulators; Eating; Emotions; Endocannabinoids; Oleic Acids; Piperidines; Polyunsaturated Alkamides; Psychomotor Performance; Pyrazoles; Rats; Rats, Wistar

The central nervous system control of food intake has been extensively studied, hence, several neurotransmitter systems regulating this function are now clearly identified, for example, the endocannabinoid and serotoninergic systems. The former stimulates feeding while the latter inhibits it. Oleamide (Ole) is a cannabimimetic molecule affecting both systems. In this work, we tested the orexigenic and anorectic potential of Ole when administered into the nucleus accumbens shell (NAcS), a brain region that has been related to the orexigenic effects of cannabinoids. Additionally, we tested if Ole administered into this nucleus affects the activity of the hypothalamic nuclei involved in feeding behaviour, just as other cannabinoids do. We found a hyperphagic effect of Ole that is mediated through CB1 activation. The combination of Ole and the CB1 antagonist, AM251, produced a hypophagia that was fully blocked by SB212084, a 5-HT2C receptor antagonist. We also show that blockade of 5-HT2C and 5-HT2A receptors in the NAcS stimulates food intake. Finally, the combination of Ole and AM251 activates hypothalamic nuclei, an effect also blocked by SB242084. In conclusion, we show, for the first time, that Ole administered into the NAcS has a dual effect on feeding behaviour, acting through cannabinoid and serotonin receptors. These effects probably result from a downstream interaction with the hypothalamus.

Topics: Aminopyridines; Animals; Eating; Feeding Behavior; Hyperphagia; Hypothalamus; Indoles; Ketanserin; Male; Motor Activity; Nucleus Accumbens; Oleic Acids; Piperidines; Pyrazoles; Rats; Rats, Wistar; Receptor, Cannabinoid, CB1; Receptor, Serotonin, 5-HT2A; Receptor, Serotonin, 5-HT2C; Serotonin 5-HT2 Receptor Antagonists

These experiments aimed to assess whether enhanced activity at the cannabinoid CB1 receptor elicits antidepressant-like effects. To examine this we administered 1 and 5 mg/kg doses of the endocannabinoid uptake inhibitor AM404; 5 and 25 microg/kg doses of HU-210, a potent CB1 receptor agonist; 1, 2.5 and 5 mg/kg of oleamide, which elicits cannabinoidergic actions; 1 and 5 mg/kg doses of AM 251, a selective CB1 receptor antagonist, as well as 10 mg/kg desipramine (a positive antidepressant control) and measured the duration of immobility, during a 5-min test session of the rat Porsolt forced swim test. Results demonstrated that administration of desipramine reduced immobility duration by about 50% and that all of AM404, oleamide and HU-210 administration induced comparable decreases in immobility that were blocked by pretreatment with AM 251. Administration of the antagonist AM 251 alone had no effect on immobility at either dose. These data suggest that enhancement of CB1 receptor signaling results in antidepressant effects in the forced swim test similar to that seen following conventional antidepressant administration.

Topics: Animals; Antidepressive Agents; Antidepressive Agents, Tricyclic; Arachidonic Acids; Desipramine; Dose-Response Relationship, Drug; Dronabinol; Male; Motor Activity; Oleic Acids; Piperidines; Pyrazoles; Rats; Rats, Long-Evans; Receptor, Cannabinoid, CB1; Swimming

Cannabinoids have been shown to impair cognition in vivo and block long-term potentiation (LTP), a candidate experimental model of learning and memory in vitro, via cannabinoid receptor (CB1) activation. cis-Oleamide (cOA) is an endogenous sleep-inducing lipid with putative cannabinomimetic properties. We hypothesise that cOA is cannabinomimetic and perform a comparative study with synthetic and endogenous cannabinoids on their effects on synaptic conditioning via two different patterns of stimulation in the hippocampal slice. CB1 agonists, R(+)-WIN55212-2 and anandamide, but not cOA blocked high frequency stimulation (HFS)-LTP. R(+)-WIN55212-2 and cOA (stereoselectively) attenuated responses to theta-burst-LTP, while anandamide did not. The anandamide transport inhibitor, AM404, attenuated HFS-LTP, an effect reversed by the CB1 receptor antagonist SR141716A but not mimicked by the vanilloid receptor agonist capsaicin. TFNO, an inhibitor of fatty acid amide hydrolase (FAAH), the enzyme responsible for degrading anandamide, failed to block HFS-LTP alone or in combination with cOA. On the contrary, this combination was as effective as cOA on its own in attenuating theta-burst-LTP. cOA effects on theta-burst-LTP were prevented in the presence of the GABA(A) receptor blocker picrotoxin, but not by pretreatment with SR141716A. These findings suggest that cOA neither directly activates CB1 receptors nor acts via the proposed "entourage" effect [Nature 389 (1997) 25] to increase titres of anandamide through FAAH inhibition. The selective effects of cOA on theta-burst-conditioning may reflect modulation of GABAergic transmission. Anandamide uptake inhibition, but not blockade of FAAH, effectively increases synaptic concentrations of endocannabinoids.

Topics: Amidohydrolases; Analysis of Variance; Animals; Animals, Newborn; Arachidonic Acids; Benzoxazines; Cannabinoids; Capsaicin; Drug Interactions; Electric Stimulation; Electrophysiology; Endocannabinoids; Excitatory Postsynaptic Potentials; Hippocampus; Hypnotics and Sedatives; In Vitro Techniques; Long-Term Potentiation; Male; Morpholines; Naphthalenes; Neurons; Oleic Acids; Piperidines; Polyunsaturated Alkamides; Pyrazoles; Rats; Rimonabant; Sleep

The unsaturated fatty acid amide oleamide (OA), which accumulates in the CSF of rats during sleep deprivation, induces electroencephalographically measured sleep when administered intracerebroventricularly. The mechanism of sleep induction by OA is unclear but may derive from enhancements of GABA or 5-HT receptor function, or alternatively from changes in the catabolism or uptake of the related fatty acid amide anandamide, an endogenous cannabinoid-1 (CB1) receptor ligand. The present study tests the latter hypothesis by administering OA alone and in combination with the CB1 receptor antagonist SR141716. As previously reported, 2.8 microg OA administered intracerebroventricularly significantly shortened electroencephalographic sleep latency. SR141716 in a dose of 3 microg had no effects on sleep by itself, but when co-administered with OA prevented its sleep-inducing effects. These data suggest that at least one aspect of the hypnotic action of OA involves interactions with the CB1 receptor system, possibly by blocking the metabolism of the endogenous CB1 receptor agonist anandamide.

Topics: Animals; Hypnotics and Sedatives; Male; Oleic Acids; Piperidines; Pyrazoles; Rats; Rats, Sprague-Dawley; Receptors, Cannabinoid; Receptors, Drug; Rimonabant; Sleep