Anandamide alters the membrane properties, halts the cell division and prevents drug efflux in multidrug resistant Staphylococcus aureus.

Antibiotic resistance is a serious public health problem throughout the world. Overcoming methicillin and multidrug-resistant Staphylococcus aureus (MRSA/MDRSA) infections has become a challenge and there is an urgent need for new therapeutic approaches. We have previously demonstrated that the endocannabinoid Anandamide (AEA) can sensitize MRSA to antibiotics. Here we have studied the mechanism of action using a MDRSA clinical isolate that are sensitized by AEA to methicillin and norfloxacin. We found that AEA treatment halts the growth of both antibiotic-sensitive and antibiotic-resistant S. aureus. The AEA-treated bacteria become elongated and the membranes become ruffled with many protrusions. AEA treatment also leads to an increase in the percentage of bacteria having a complete septum, suggesting that the cell division is halted at this stage. The latter is supported by cell cycle analysis that shows an accumulation of bacteria in the G2/M phase after AEA treatment. We further observed that AEA causes a dose-dependent membrane depolarization that is partly relieved upon time. Nile red staining of the bacterial membranes indicates that AEA alters the membrane structures. Importantly, 4'-6-diamidino-2-phenylindole (DAPI) accumulation assay and ethidium bromide efflux (EtBr) assay unveiled that AEA leads to a dose-dependent drug accumulation by inhibiting drug efflux. In conclusion, our study demonstrates that AEA interferes with cell division, alters the membrane properties of MDRSA, and leads to increased intracellular drug retention, which can contribute to the sensitization of MDRSA to antibiotics.

Characterization of pepcan-23 as pro-peptide of RVD-hemopressin (pepcan-12) and stability of hemopressins in mice.

Hemopressins ((x)-PVNFKLLSH) or peptide endocannabinoids (pepcans) can bind to cannabinoid receptors. RVD-hemopressin (pepcan-12) was shown to act as endogenous allosteric modulator of cannabinoid receptors, with opposite effects on CB1 and CB2, respectively. Moreover, the N-terminally elongated pepcan-23 was detected in different tissues and was postulated to be the pro-peptide of RVD-hemopressin. Currently, data about the pharmacokinetics, tissue distribution and stability of hemopressin-type peptides are lacking. Here we investigated the secondary structure and physiological role of pepcan-23 as precursor of RVD-hemopressin. We assessed the metabolic stability of these peptides, including hemopressin. Using LC-ESI-MS/MS, pepcan-23 was measured in mouse tissues and human whole blood (~50 pmol/mL) and in plasma was the most stable endogenous peptide containing the hemopressin sequence. Using peptide spiked human whole blood, mouse adrenal gland and liver homogenates demonstrate that pepcan-23 acts as endogenous pro-peptide of RVD-hemopressin. Furthermore, administered pepcan-23 converted to RVD-hemopressin in mice. In circular dichroism spectroscopy, pepcan-23 showed a helix-unordered-helix structure and efficiently formed complexes with divalent metal ions, in particular Cu(II) and Ni(II). Hemopressin and RVD-hemopressin were not bioavailable to the brain and showed poor stability in plasma, in agreement with their overall poor biodistribution. Acute hemopressin administration (100 mg/kg) did not modulate endogenous RVD-hemopressin/pepcan-23 levels or influence the endocannabinoid lipidome but increased 1-stearoyl-2-arachidonoyl-sn-glycerol. Overall, we show that pepcan-23 is a biological pro-peptide of RVD-hemopressin and divalent metal ions may regulate this process. Given the lack of metabolic stability of hemopressins, administration of pepcan-23 as pro-peptide may be suitable in pharmacological experiments as it is converted to RVD-hemopressin in vivo.

The rise and fall of anandamide: processes that control synthesis, degradation, and storage.

Anandamide is an endocannabinoid derived from arachidonic acid-containing membrane lipids and has numerous biological functions. Its effects are primarily mediated by the cannabinoid receptors CB1 and CB2, and the vanilloid TRPV1 receptor. Anandamide is known to be involved in sleeping and eating patterns as well as pleasure enhancement and pain relief. This manuscript provides a review of anandamide synthesis, degradation, and storage and hence the homeostasis of the anandamide signaling system.

Inhibitions of anandamide transport and FAAH synthesis decrease apoptosis and oxidative stress through inhibition of TRPV1 channel in an in vitro seizure model.

The expression level of TRPV1 is high in hippocampus which is a main epileptic area in the brain. In addition to the actions of capsaicin (CAP) and reactive oxygen species (ROS), the TRPV1 channel is activated in neurons by endogenous cannabinoid, anandamide (AEA). In the current study, we investigated the role of inhibitors of TRPV1 (capsazepine, CPZ), AEA transport (AM404), and FAAH (URB597) on the modulation of Ca2+ entry, apoptosis, and oxidative stress in in vitro seizure-induced rat hippocampus and human glioblastoma (DBTRG) cell line. The seizure was induced in the hippocampal and DBTRG neurons using in vitro 4-aminopyridine (4-AP) to trigger a seizure-like activity model. CPZ and AM404 were fully effective in reversing 4-AP-induced intracellular free Ca2+ concentration of the hippocampus and TRPV1 current density of DBTRG. However, AEA and CAP did not activate TRPV1 in the URB597-treated neurons. Hence, we observed TRPV1 blocker effects of URB597 in the DBTRG neurons. In addition, the AM404 and CPZ treatments decreased intracellular ROS production, mitochondrial membrane depolarization, apoptosis, caspases 3 and 9 values in the hippocampus. In conclusion, the results indicate that inhibition of AEA transport, FAAH synthesis, and TRPV1 activity can result in remarkable neuroprotective effects in the epileptic neurons. Possible molecular pathways of involvement of capsazepine (CPZ) and AM4040 in anandamide and capsaicin (CAP)-induced apoptosis, oxidative stress, and Ca2+ accumulation through TRPV1 channel in the seizure-induced rat hippocampus and human glioblastoma neurons. The TRPV1 channel is activated by different stimuli including reactive oxygen species (ROS), anandamide (AEA), and CAP and it is blocked by capsazepine (CPZ). Cannabinoid receptor type 1 (CB1) is also activated by AEA. The AEA levels in cytosol are decreased by fatty acid amide hydrolase (FAAH) enzyme. Inhibition of FAAH through URB597 induces stimulation of CB1 receptor through accumulation AEA. URB597 acts antiepileptic effects through inhibition of TRPV1. Overloaded Ca2+ concentration of mitochondria can induce an apoptotic program by stimulating the release of apoptosis-promoting factors such as caspases 3 and caspase 9 by generating ROS due to respiratory chain damage. AM404 and CPZ reduce TRPV1 channel activation and Ca2+ entry in the in vitro 4-AP seizure model-induced hippocampal and glioblastoma neurons.

Perspectivas futuras en el tratamiento farmacológico de la vejiga hiperactiva / Future perspectives in pharmacological treatment of overactive bladder

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Big conductance calcium-activated potassium channel openers control spasticity without sedation.

BACKGROUND AND PURPOSE: Our initial aim was to generate cannabinoid agents that control spasticity, occurring as a consequence of multiple sclerosis (MS), whilst avoiding the sedative side effects associated with cannabis. VSN16R was synthesized as an anandamide (endocannabinoid) analogue in an anti-metabolite approach to identify drugs that target spasticity. EXPERIMENTAL APPROACH: Following the initial chemistry, a variety of biochemical, pharmacological and electrophysiological approaches, using isolated cells, tissue-based assays and in vivo animal models, were used to demonstrate the activity, efficacy, pharmacokinetics and mechanism of action of VSN16R. Toxicological and safety studies were performed in animals and humans. KEY RESULTS: VSN16R had nanomolar activity in tissue-based, functional assays and dose-dependently inhibited spasticity in a mouse experimental encephalomyelitis model of MS. This effect occurred with over 1000-fold therapeutic window, without affecting normal muscle tone. Efficacy was achieved at plasma levels that are feasible and safe in humans. VSN16R did not bind to known CB1 /CB2 /GPPR55 cannabinoid-related receptors in receptor-based assays but acted on a vascular cannabinoid target. This was identified as the major neuronal form of the big conductance, calcium-activated potassium (BKCa ) channel. Drug-induced opening of neuronal BKCa channels induced membrane hyperpolarization, limiting excessive neural-excitability and controlling spasticity. CONCLUSIONS AND IMPLICATIONS: We identified the neuronal form of the BKCa channel as the target for VSN16R and demonstrated that its activation alleviates neuronal excitability and spasticity in an experimental model of MS, revealing a novel mechanism to control spasticity. VSN16R is a potential, safe and selective ligand for controlling neural hyper-excitability in spasticity.

4'-O-methylhonokiol increases levels of 2-arachidonoyl glycerol in mouse brain via selective inhibition of its COX-2-mediated oxygenation.

BACKGROUND AND PURPOSE: 4'-O-methylhonokiol (MH) is a natural product showing anti-inflammatory, anti-osteoclastogenic, and neuroprotective effects. MH was reported to modulate cannabinoid CB2 receptors as an inverse agonist for cAMP production and an agonist for intracellular [Ca2+]. It was recently shown that MH inhibits cAMP formation via CB2 receptors. In this study, the exact modulation of MH on CB2 receptor activity was elucidated and its endocannabinoid substrate-specific inhibition (SSI) of cyclooxygenase-2 (COX-2) and CNS bioavailability are described for the first time. METHODS: CB2 receptor modulation ([35S]GTPγS, cAMP, and ß-arrestin) by MH was measured in hCB2-transfected CHO-K1 cells and native conditions (HL60 cells and mouse spleen). The COX-2 SSI was investigated in RAW264.7 cells and in Swiss albino mice by targeted metabolomics using LC-MS/MS. RESULTS: MH is a CB2 receptor agonist and a potent COX-2 SSI. It induced partial agonism in both the [35S]GTPγS binding and ß-arrestin recruitment assays while being a full agonist in the cAMP pathway. MH selectively inhibited PGE2 glycerol ester formation (over PGE2) in RAW264.7 cells and significantly increased the levels of 2-AG in mouse brain in a dose-dependent manner (3 to 20 mg kg(-1)) without affecting other metabolites. After 7 h from intraperitoneal (i.p.) injection, MH was quantified in significant amounts in the brain (corresponding to 200 to 300 nM). CONCLUSIONS: LC-MS/MS quantification shows that MH is bioavailable to the brain and under condition of inflammation exerts significant indirect effects on 2-AG levels. The biphenyl scaffold might serve as valuable source of dual CB2 receptor modulators and COX-2 SSIs as demonstrated by additional MH analogs that show similar effects. The combination of CB2 agonism and COX-2 SSI offers a yet unexplored polypharmacology with expected synergistic effects in neuroinflammatory diseases, thus providing a rationale for the diverse neuroprotective effects reported for MH in animal models.

The cannabinoid receptor antagonist AM251 increases paraoxon and chlorpyrifos oxon toxicity in rats.

Organophosphorus anticholinesterases (OPs) elicit acute toxicity by inhibiting acetylcholinesterase (AChE), leading to acetylcholine accumulation and overstimulation of cholinergic receptors. Endocannabinoids (eCBs, e.g., arachidonoyl ethanolamide [AEA] and 2-arachidonoyl glycerol [2-AG]) are neuromodulators that regulate neurotransmission by reducing neurotransmitter release. The eCBs are degraded by the enzymes fatty acid amide hydrolase (FAAH, primarily involved in hydrolysis of AEA) and monoacylglycerol lipase (MAGL, primarily responsible for metabolism of 2-AG). We previously reported that the cannabinoid receptor agonist WIN 55,212-2 reduced cholinergic toxicity after paraoxon exposure. This study compared the effects of the cannabinoid receptor antagonist AM251 on acute toxicity following either paraoxon (PO) or chlorpyrifos oxon (CPO). CPO was more potent in vitro than PO at inhibiting AChE (≈ 2 fold), FAAH (≈ 8 fold), and MAGL (≈ 19 fold). Rats were treated with vehicle, PO (0.3 and 0.6 mg/kg, sc) or CPO (6 and 12 mg/kg, sc) and subsets treated with AM251 (3mg/kg, ip; 30 min after OP). Signs of toxicity were recorded for 4h and rats were then sacrificed. OP-treated rats showed dose-related involuntary movements, with AM251 increasing signs of toxicity with the lower dosages. PO and CPO elicited excessive secretions, but AM251 had no apparent effect with either OP. Lethality was increased by AM251 with the higher dosage of PO, but no lethality was noted with either dosage of CPO, with or without AM251. Both OPs caused extensive inhibition of hippocampal AChE and FAAH (>80-90%), but only CPO inhibited MAGL (37-50%). These results provide further evidence that eCB signaling can influence acute OP toxicity. The selective in vivo inhibition of MAGL by CPO may be important in the differential lethality noted between PO and CPO with AM251 co-administration.

Correlating FAAH and anandamide cellular uptake inhibition using N-alkylcarbamate inhibitors: from ultrapotent to hyperpotent.

Besides the suggested role of a putative endocannabinoid membrane transporter mediating the cellular uptake of the endocannabinoid anandamide (AEA), this process is intrinsically coupled to AEA degradation by the fatty acid amide hydrolase (FAAH). Differential blockage of each mechanism is possible using specific small-molecule inhibitors. Starting from the natural product-derived 2E,4E-dodecadiene scaffold previously shown to interact with the endocannabinoid system (ECS), a series of diverse N-alkylcarbamates were prepared with the aim of generating novel ECS modulators. While being inactive at cannabinoid receptors and monoacylglycerol lipase, these N-alkylcarbamates showed potent to ultrapotent picomolar FAAH inhibition in U937 cells. Overall, a highly significant correlation (Spearman's rho=0.91) was found between the inhibition of FAAH and AEA cellular uptake among 54 compounds. Accordingly, in HMC-1 cells lacking FAAH expression the effect on AEA cellular uptake was dramatically reduced. Unexpectedly, 3-(4,5-dihydrothiazol-2-yl)phenyl carbamates and the 3-(1,2,3-thiadiazol-4-yl)phenyl carbamates WOBE490, WOBE491 and WOBE492 showed a potentiation of cellular AEA uptake inhibition in U937 cells, resulting in unprecedented femtomolar (hyperpotent) IC50 values. Potential methodological issues and the role of cellular accumulation of selected probes were investigated. It is shown that albumin impacts the potency of specific N-alkylcarbamates and, more importantly, that accumulation of FAAH inhibitors can significantly increase their effect on cellular AEA uptake. Taken together, this series of N-alkylcarbamates shows a FAAH-dependent inhibition of cellular AEA uptake, which can be strongly potentiated using specific head group modifications. These findings provide a rational basis for the development of hyperpotent AEA uptake inhibitors mediated by ultrapotent FAAH inhibition.

Ketoconazole inhibits the cellular uptake of anandamide via inhibition of FAAH at pharmacologically relevant concentrations.

BACKGROUND: The antifungal compound ketoconazole has, in addition to its ability to interfere with fungal ergosterol synthesis, effects upon other enzymes including human CYP3A4, CYP17, lipoxygenase and thromboxane synthetase. In the present study, we have investigated whether ketoconazole affects the cellular uptake and hydrolysis of the endogenous cannabinoid receptor ligand anandamide (AEA). METHODOLOGY/PRINCIPAL FINDINGS: The effects of ketoconazole upon endocannabinoid uptake were investigated using HepG2, CaCo2, PC-3 and C6 cell lines. Fatty acid amide hydrolase (FAAH) activity was measured in HepG2 cell lysates and in intact C6 cells. Ketoconazole inhibited the uptake of AEA by HepG2 cells and CaCo2 cells with IC50 values of 17 and 18 µM, respectively. In contrast, it had modest effects upon AEA uptake in PC-3 cells, which have a low expression of FAAH. In cell-free HepG2 lysates, ketoconazole inhibited FAAH activity with an IC50 value (for the inhibitable component) of 34 µM. CONCLUSIONS/SIGNIFICANCE: The present study indicates that ketoconazole can inhibit the cellular uptake of AEA at pharmacologically relevant concentrations, primarily due to its effects upon FAAH. Ketoconazole may be useful as a template for the design of dual-action FAAH/CYP17 inhibitors as a novel strategy for the treatment of prostate cancer.

N-Palmitoylethanolamine depot injection increased its tissue levels and those of other acylethanolamide lipids.

N-Palmitoylethanolamine (NAE 16:0) is an endogenous lipid signaling molecule that has limited water solubility, and its action is short-lived due to its rapid metabolism. This poses a problem for use in vivo as oral administration requires a high concentration for significant levels to reach target tissues, and injection of the compound in a dimethyl sulfoxide- or ethanol-based vehicle is usually not desirable during long-term treatment. A depot injection of NAE 16:0 was successfully emulsified in sterile corn oil (10 mg/kg) and administered in young DBA/2 mice in order to elevate baseline levels of NAE 16:0 in target tissues. NAE 16:0 levels were increased in various tissues, particularly in the retina, 24 and 48 hours following injections. Increases ranged between 22% and 215% (above basal levels) in blood serum, heart, brain, and retina and induced an entourage effect by increasing levels of other 18 carbon N-Acylethanolamines (NAEs), which ranged between 31% and 117% above baseline. These results indicate that NAE 16:0 can be used as a depot preparation, avoiding the use of inadequate vehicles, and can provide the basis for designing tissue-specific dosing regimens for therapies involving NAEs and related compounds.

¿Media la dopamina los efectos psicóticos del Cannabis? Revisión e integración de los hallazgos a través de disciplinas / Does dopamine mediate the psychosis-inducing effects of cannabis? A review and integration of findings across disciplines

Los estudios epidemiológicos efectuados en la población general han demostrado sistemáticamente que el consumo de Cannabis aumenta de modo dependiente de la dosis el riesgo de desarrollar trastornos psicóticos. Aunque los indicios epidemiológicos entre el consumo de Cannabis y las psicosis han obtenido una atención considerable, apenas se conoce el mecanismo biológico mediante el que esta droga aumenta el riesgo de psicosis. La investigación en estudios efectuados en animales sugiere que el delta- 9-tetrahidrocanabinol (THC, el componente psicoactivo principal del Cannabis) aumenta los niveles de dopamina en diversas regiones del cerebro, incluido el núcleo estriado y el área prefrontal. Dado que se ha formulado la hipótesis de que la dopamina representa una vía final común decisiva entre la biología del cerebro y la experiencia real de psicosis, inicialmente prestar atención a este neurotransmisor podría ser productivo en el examen de los efectos psicotomiméticos del Cannabis. Por consiguiente, en la presente revisión se examinan las pruebas concernientes a las interacciones entre el THC, los endocanabinoides y la dopamina en la región tanto cortical como subcortical implicadas en las psicosis, y se consideran los posibles mecanismos por los que una disregulación de la dopamina inducida por el consumo de Cannabis podría dar lugar a delirios y alucinaciones. Se concluye que podrían emprenderse productivamente estudios adicionales sobre los mecanismos subyacentes que relacionan el consumo de Cannabis y las psicosis desde una perspectiva de una sensibilización progresiva del desarrollo, como consecuencia de interacciones genes-ambiente (AU)

General population epidemiological studies have consistently found that cannabis use increases the risk of developing psychotic disorders in a dose-dependent manner. While the epidemiological signal between cannabis and psychosis has gained considerable attention, the biological mechanism whereby cannabis increases risk for psychosis remains poorly understood. Animal research suggests that delta-9- tetrahydrocannabinol (THC, the main psychoactive component of cannabis) increases dopamine levels in several regions of the brain, including striatal and prefrontal areas. Since dopamine is hypothesized to represent a crucial common final pathway between brain biology and actual experience of psychosis, a focus on dopamine may initially be productive in the examination of the psychotomimetic effects of cannabis. Therefore, this review examines the evidence concerning the interactions between THC, endocannabinoids and dopamine in the cortical as well as subcortical regions implicated in psychosis, and considers possible mechanisms whereby cannabis-induced dopamine dysregulation may give rise to delusions and hallucinations. It is concluded that further study of the mechanisms underlying the link between cannabis and psychosis may be conducted productively from the perspective of progressive developmental sensitization, resulting from gene-environment interactions (AU)

Implicación funcional del sistema cannabinoide endógeno en la homeostasis emocional / Functional role of the endocannabinoid system in emotional homeostasis

Introducción y desarrollo. El cannabis y sus derivados producen efectos complejos sobre las respuestas de ansiedad en humanos que van desde estados de relajación a reacciones de pánico. Diversos estudios en animales abundan en la complejidad de este mecanismo y revelan un perfil de acción bifásico. En dosis bajas parecen producir efectos de tipo ansiolítico, mientras que en dosis altas inducen efectos de tipo ansiogénico. Los mecanismos neurobiológicos subyacentes a estas diferentesrespuestas aún no se han dilucidado completamente. La observación de un fenotipo de tipo ansiogénico tras el bloqueo farmacológico y genético de los receptores cannabinoides CB1 en roedores, junto a la amplia presencia de receptores cannabinoides en regiones cerebrales relacionadas con el control emocional, como la amígdala, el hipocampo y la corteza, son algunosde los datos que apuntan a la participación del sistema cannabinoide endógeno en la regulación de los estados de ansiedad. Se han descrito además respuestas de tipo ansiolítico tras la administración de inhibidores de la degradación de los ligandos cannabinoides endógenos. Conclusiones. En su conjunto, los datos presentados a lo largo de esta revisión indican que el sistemacannabinoide endógeno participa en el control de la homeostasis emocional y sugieren que la manipulación farmacológica de este sistema podría ser una opción para el tratamiento de los trastornos de ansiedad

Introduction and development. Cannabis and derivatives induce complex effects on anxiety in humans andexperimental animals. At low doses, cannabinoid agonists seem to exert anxiolytic actions, while at high doses anxiety and panic estates are often reported. Diverse animal models confirm this particular biphasic profile; however, the underlying neurobiological mechanisms have not been completely elucidated. The anxiogenic-like behavioral phenotype observed following both pharmacological and genetic blockade of cannabinoid CB1 receptors, together with the abundant expression of cannabinoid receptors within brain areas particularly involved in emotional control, such as amygdala, hippocampus and cortex, are among the numerous evidences that account for the participation of the endocannabinoid system in the regulation of anxietystates. Moreover, blockade of endogenous cannabinoid ligands deactivation has been reported to induce anxiolytic-like responses. Conclusions. Taken together, present data reinforce the involvement of the endocannabinoid system in the control of emotional homeostasis and further suggest the pharmacological manipulation of the endocannabinoid system as a potentialtherapeutic tool in the management of anxiety-related disorders

Papel modulador de los endocanabinoides en el sueño / The modulatory role of endocannabinoids in sleep

El sistema de canabinoides endógenos, o endocanabinoides, está presente en el sistema nervioso central (SNC) tanto de roedores como en humanos. Este sistema incluye receptores, ligandos endógenos y enzimas. La presencia en el SNC de receptores para canabinoides, denominados CB1, se ha descrito en la corteza cerebral, el hipocampo, el cerebeloy el tallo cerebral. Dicha localización neuroanatómica sugiere que este receptor podría modular diversas funciones fisiológicas como la consolidación de la memoria, el control motor y la generación del sueño. Desarrollo. En la actualidad se ha comunicadola presencia en el SNC de lípidos que se unen al receptor CB1. La administración de dichas moléculas induce efectos canabimiméticos, de tal forma que se han sugerido estos lípidos como canabinoides endógenos o endocanabinoides. Anandamida, 2-araquidonilglicerol, virodamina, noladin-éter y N-araquidonildopamina son moléculas que pertenecen a la familia de losendocanabinoides. Dado que la anandamida fue el primer endocanabinoide descrito, ha sido el más estudiado. Experimentos farmacológicos han demostrado que este endocanabinoide induce diversos cambios intracelulares y conductuales. Conclusiones. En este trabajo se revisan los aspectos farmacológicos más importantes de los canabinoides exógenos y el papel neurobiológicodel sistema de endocanabinoides, incluyendo ligandos endógenos y exógenos y receptores, así como sus efectos farmacológicos en diversas conductas, especialmente en la modulación del sueño

The endogenous cannabinoid, or endocannabinoid, system is present in the central nervous system(CNS) of rodents and humans. This system includes receptors, endogenous ligands and enzymes. The presence of cannabinoid receptors, called CB1, in the CNS has been reported in the cerebral cortex, the hippocampus, the cerebellum and the brain stem.This neuroanatomical location suggests that this receptor could modify several physiological functions, such as the consolidation of memory, motor control and the generation of sleep. Development. Recent reports have described the presence of lipids in the CNS that bind to the CB1 receptor. Administration of said molecules induces cannabimimetic effects, and henceit has been suggested that these lipids are endogenous cannabinoids or endocannabinoids. Anandamide, 2-arachidonylglycerol, virodhamine, noladin ether and N-arachidonyldopamine are molecules that belong to the endocannabinoid family. Anandamidehas received more attention from researchers because it was the first endocannabinoid to be reported. Pharmacological experiments have shown that this endocannabinoid induces several different intracellular and behavioural changes.Conclusions. In this study, we review the most important pharmacological aspects of exogenous cannabinoids and theneurobiological role played by the endocannabinoid system, including endogenous and exogenous ligands and receptors. We also examine their pharmacological effects on different behaviours, with particular attention given to the modulation of sleep

Rimonabant en el tratamiento de la diabetes tipo 2. Nuevas evidencias / Rimonabant in the treatment of diabetes type 2: new evidence

El descubrimiento de los receptores cannabinoides y de sus ligandos endógenos, los endocannabinoides, ha permitido mejorar el conocimiento de diversos procesos fisiológicos y ha abierto perspectivas terapéuticas de gran interés. Estudios recientes han esclarecido el papel crucial que desempeña el sistema endocannabinoide en el control de la ingesta alimentaria y el metabolismo a través de los receptores CB1. La activación de dichos receptores promueve la ingesta y produce una amplia gama de acciones metabólicas independientes dirigidas a obtener una acumulación de energía. Estas acciones tienen lugar en los principales órganos periféricos encargados de la regulación del metabolismo, incluyendo el tejido adiposo, el hígado, el músculo esquelético y el páncreas. Los resultados obtenidos recientemente en los diferentes ensayos clínicos realizados con rimonabant, el primer antagonista del receptor CB1, sugieren un futuro prometedor para esta nueva generación de fármacos que actúan en una diana farmacológica emergente para el tratamiento de la diabetes tipo 2 y el manejo global del conjunto de factores de riesgo cardiometabólico. Los ensayos clínicos actualmente en desarrollo permitirán determinar el alcance terapéutico a largo plazo de los efectos beneficiosos que rimonabant induce sobre el metabolismo. Esta revisión recoge los hallazgos recientes que han permitido definir el papel que desempeña el sistema endocannabinoide en el control del equilibrio energético y del metabolismo lipídico e hidrocarbonado, y expone las perspectivas terapéuticas innovadoras que se han abierto con el desarrollo de los antagonistas selectivos de los receptores cannabinoides CB1, concretamente en el paciente con diabetes tipo 2 (AU)

The discovery of the cannabinoid receptors and their endogenous ligands, the endocannabinoids, has increased the knowledge of a number of physiological processes and has opened new therapeutic perspectives of interest. Recent studies have clarified the crucial role of the endocannabinoid system in controlling food intake and metabolism by means of the CB1 receptors. CB1 receptor activation promotes food intake and produces a wide range of independent metabolic actions leading to energy accumulation. These actions take place in the major peripheral organs responsible for the regulation of metabolism, including adipose tissue, liver, skeletal muscle and pancreas. Recent findings in various clinical trials with rimonabant, the first CB1 receptor antagonist, suggest a promising future forthis new generation of drugs that act on an emerging pharmacological target for the treatment of type 2 diabetes and the overall management of all cardiometabolic risk factors. Clinical trials currently under development will determine the long-term therapeutic impact of the beneficial effects on metabolism induced by rimonabant. This review reflects the recent findings that have clarified the role of the endocannabinoid system in controlling energy balance and lipid and carbohydrate metabolism, and discusses novel therapeutic perspectives that have been introduced with the development of selective antagonists of the cannabinoid CB1 receptors, specifically in type 2 diabetic patients (AU)

Sistema cannabinoide endógeno: ligandos y receptores acoplados a mecanismos de transducción de señales / Endogenous cannabinoid system: ligands and receptors matched to transduction signals mechanisms

Numerosos estudios realizados en las dos últimas décadas han demostrado la existencia en el organismo animal de un sistema cannabinoide endógeno, constituido por unos ligandos, los endocannabinoides. Se han descrito dos tipos de receptores para cannabinoides: los denominados CB1, localizados preferentemente en cerebro y los CB2 que están localizados en el sistema inmune. Los dos endocannabinoides de los que más datos se dispone son la araquidoniletanolamida o anandamida y el 2-araquidonilglicerol, habiéndose postulado su posible actuación como neurotransmisores o neuromoduladores. La distribución cerebral de los endocannabinoides y de los receptores CB1 ha permitido conocer las funciones fisiológicas en las que está involucrado este sistema. Participa, a través de modular la actividad de los neurotransmisores, en la regulación del comportamiento motor y de la secreción de hormonas adenohipofisarias, interacciona con la dopamina y con el GABA, mientras que, en el caso de la memoria y el aprendizaje, lo hace con el GABA y el glutamato. La dopamina y los péptidos opioides podrían estar implicados en la participación de los endocannabinoides en el sistema de recompensa y en el control de la nocicepción. Por otro lado, la síntesis de anandamida, en condiciones de isquemia, podría jugar un papel protector en las regiones cerebrales afectadas. Se ha visto que este compuesto inhibe la captación mitocondrial de calcio y la liberación de glutamato, efectos ámbos que contribuyen a la citotoxicidad cerebral (AU)

Numerous studies carried out in the last two decades have shown the existence in the animal organism of an endogenous cannabinoide system comprising certain ligands, the endocannabinoides. Two types of receptors for cannabinoides have been described, those known as CB1, located predominantly in the brain, and the CB2 located in the immune system. The two endocannabinoides on which there is more available data are the arachidonylethanolamide or anandamide and the 2-arachidonylglycerol, their possible action as neurotransmitters or neuromodulators having been postulated. The cerebral distribution of the endocannabinoides and the CB1 receptors has led to knowledge of the physiological functions that involve this system. It participates by modulating the action of the neurotransmitters, in regulating motor behaviour and the secretion of adenohypophysary hormones, interacts with dopamine and the GABA and, in the case of memory and learning, it interacts with the GABA and the glutamate. The dopamine and the opioid peptides may be implicated in the participation of the endocannabinoides in the drug reward system and in the control of nociception. At the same time, the synthesis of anandamine in ischemia may play a protective role in the cerebral regions affected. It has been seen that this compound inhibits the mitochondrial uptake of calcium and the liberation of glutamate, both effects that contribute to cerebral cytoxicity (AU)

Adicción y sistema cannabinoide endógeno: papel del receptor para cannabinoides CB1 en la fisiología de las neuronas dopaminérgicas mesotelencefálicas / Addiction and endogenous cannabinoid system: the role of cannabinoid receptor CB1 in the mesotelencephalic dopaminergic neurones physiology

El sistema cannabinoide endogeno es un nuevo sistema de comunicación intercelular compuesto por los receptores para cannabinoides CB-1 y CB-2 y varios transmisores lipidicos, que incluyen a la anandamida y el 2-araquidonilglicerol. Los receptores para cannabinoides CB1 y CB2 son la diana farmacológica de los cannabinoides naturales, los compuestos psicoactivos presentes en las preparaciones de Cannabis sativa, que se consumen como droga ilegal. La investigacion en modelos animales ha constatado que los cannabinoides inducen cambios en los sistemas cerebrales de recompensa, en especial sobre las neuronas dopaminérgicas mesotelencefálicas, equiparables a los que inducen otras drogas como los opiáceos y el etanol. El presente trabajo analiza las evidencias anatómicas, bioquímicas y farmacológicas que apoyan el papel del sistema cannabinoide endógeno en la modulación de la transmisión dopaminérgica. El receptor CB1 no sólo se localiza en las neuronas que expresan receptores para dopamina, sino que se expresa también en células dopaminéricas del mesencéfalo y el hipotálamo. La estimulación de los receptores para dopamina D2 es, además, el estímulo más potente capaz de liberar anandamida que se ha descrito hasta la fecha. La liberación de anandamida bloquearía la hiperactividad comportamental asociada a un exceso de señal dopaminergica. Estos hallazgos permiten esperar que fármacos capaces de interferir con el sistema cannabinoide endógeno puedan ser útiles en la terapéutica de procesos con participación dopaminérgica como la adicción a drogas (AU)

The endogenous cannabinoid transmission is a new cell signalling system constituted by the cannabinoid CB-1 and CB2 receptors, as well as by several lipid transmitters including anandamide and 2-arachidonoylglycerol.The cannabinoid receptors are the pharmacological targets of the psychoactive constituents of cannabis sativa preparations, commonly used as illegal recreational drugs. Several lines of research using animal models have established that cannabinoids are drugs that modify the activity of the brain reward system, specially the physiology of mesotelencephalic dopaminergic neurones, in a way that resemble the actions of ethanol or the opiates. The present work analyse the anatomical, biochemical and pharmacological evidences that support the role of the endogenous cannabinoid system as a modulator of dopamine transmission in the brain. Cannabinoid CB-1 receptor are present in both, dopamine receptor-containing neurones and mesencephalic and hypothalamic dopaminergic neurones. Moreover, the pharmacological stimulation of striatal dopamine D-2 receptors is the most potent activator of anandamide release known to date. The released anandamide will act as an endogenous break to the hyperactivity associated with a high dopaminergic output. These findings allow us to propose that drugs which interfere with the endogenous cannabinoid system might be useful as a therapy in that problems where the dopamine system intervene as addictions (AU)