anandamide
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Alterations in the excitability of dorsal root ganglion (DRG) neurons are critical in the pathogenesis of acute and chronic pain. Neurotransmitter release from the terminals of DRG neurons is regulated by cannabinoid receptor 1 (CB1) and transient receptor potential vanilloid 1 (TRPV1), both activated by anandamide (AEA). In our experiments, the AEA precursor N-arachidonoylphosphatidylethanolamine (20:4-NAPE) was used to study the modulation of nociceptive DRG neurons excitability using K+-evoked Ca2+ transients. Intrathecal administration was used to evaluate in vivo effects. Application of 20:4-NAPE at lower concentrations (10 nM - 1 μM) decreased the excitability of DRG neurons, whereas the higher (10 μM) increased it. Both effects of 20:4-NAPE were blocked by the N-acylphosphatidylethanolamine phospholipase D (NAPE-PLD) inhibitor LEI-401. Similarly, lower concentrations of externally applied AEA (1 nM - 10 nM) inhibited DRG neurons, whereas higher concentration (100 nM) did not change it. High AEA concentration (10 μM) evoked Ca2+ transients dependent on TRPV1 activation in separate experiments. Inhibition of the CB1 receptor by PF514273 (400 nM) prevented the 20:4-NAPE- and AEA-induced inhibition, whereas TRPV1 inhibition by SB366791 (1 μM) prevented the increased DRG neuron excitability. In behavioral tests, lower 20:4-NAPE concentration caused hyposensitivity, while higher evoked mechanical allodynia. Intrathecal LEI-401 prevented both in vivo effects of 20:4-NAPE. These results highlight anti- and pro-nociceptive effects of 20:4-NAPE mediated by CB1 and TRPV1 in concentration-dependent manner. Our study underscores the complexity of endocannabinoid signaling in pain transmission modulation and highlights 20:4-NAPE as a potential therapeutic target, offering new insights for developing analgesic strategies.
- MeSH
- endokanabinoidy farmakologie metabolismus MeSH
- fosfatidylethanolaminy * farmakologie MeSH
- fosfolipasa D * metabolismus antagonisté a inhibitory MeSH
- kationtové kanály TRPV metabolismus MeSH
- krysa rodu rattus MeSH
- kyseliny arachidonové * farmakologie MeSH
- neurony * účinky léků metabolismus MeSH
- polynenasycené alkamidy farmakologie MeSH
- potkani Sprague-Dawley MeSH
- receptor kanabinoidní CB1 metabolismus MeSH
- spinální ganglia * účinky léků metabolismus cytologie MeSH
- vápník metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Three decades ago, the first endocannabinoid, anandamide (AEA), was identified, and its analgesic effect was recognized in humans and preclinical models. However, clinical trial failures pointed out the complexity of the AEA-induced analgesia. The first synapses in the superficial laminae of the spinal cord dorsal horn represent an important modulatory site in nociceptive transmission and subsequent pain perception. The glutamatergic synaptic transmission at these synapses is strongly modulated by two primary AEA-activated receptors, cannabinoid receptor 1 (CB1) and transient receptor potential vanilloid 1 (TRPV1), both highly expressed on the presynaptic side formed by the endings of primary nociceptive neurons. Activation of these receptors can have predominantly inhibitory (CB1) and excitatory (TRPV1) effects that are further modulated under pathological conditions. In addition, dual AEA-mediated signaling and action may occur in primary sensory neurons and dorsal horn synapses. AEA application causes balanced inhibition and excitation of primary afferent synaptic input on superficial dorsal horn neurons in normal conditions, whereas peripheral inflammation promotes AEA-mediated inhibition. This review focuses mainly on the modulation of synaptic transmission at the spinal cord level and signaling in primary nociceptive neurons by AEA via CB1 and TRPV1 receptors. Furthermore, the spinal analgesic effect in preclinical studies and clinical aspects of AEA-mediated analgesia are considered.
- MeSH
- endokanabinoidy * metabolismus MeSH
- kationtové kanály TRPV metabolismus MeSH
- kyseliny arachidonové * metabolismus farmakologie MeSH
- lidé MeSH
- mícha * metabolismus účinky léků MeSH
- nervový přenos * fyziologie účinky léků MeSH
- nocicepce fyziologie účinky léků MeSH
- nociceptory metabolismus účinky léků fyziologie MeSH
- polynenasycené alkamidy * metabolismus MeSH
- receptor kanabinoidní CB1 metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Cannabidiol (CBD), a non-psychotomimetic constituent of Cannabis sativa, has been recently approved for epileptic syndromes often associated with Autism spectrum disorder (ASD). However, the putative efficacy and mechanism of action of CBD in patients suffering from ASD and related comorbidities remain debated, especially because of the complex pharmacology of CBD. We used pharmacological, immunohistochemical and biochemical approaches to investigate the effects and mechanisms of action of CBD in the recently validated Fmr1-Δexon 8 rat model of ASD, that is also a model of Fragile X Syndrome (FXS), the leading monogenic cause of autism. CBD rescued the cognitive deficits displayed by juvenile Fmr1-Δexon 8 animals, without inducing tolerance after repeated administration. Blockade of CA1 hippocampal GPR55 receptors prevented the beneficial effect of both CBD and the fatty acid amide hydrolase (FAAH) inhibitor URB597 in the short-term recognition memory deficits displayed by Fmr1-Δexon 8 rats. Thus, CBD may exert its beneficial effects through CA1 hippocampal GPR55 receptors. Docking analysis further confirmed that the mechanism of action of CBD might involve competition for brain fatty acid binding proteins (FABPs) that deliver anandamide and related bioactive lipids to their catabolic enzyme FAAH. These findings demonstrate that CBD reduced cognitive deficits in a rat model of FXS and provide initial mechanistic insights into its therapeutic potential in neurodevelopmental disorders.
- MeSH
- hipokampální oblast CA1 účinky léků metabolismus MeSH
- hipokampus * účinky léků metabolismus MeSH
- kanabidiol * farmakologie terapeutické užití MeSH
- krysa rodu rattus MeSH
- modely nemocí na zvířatech * MeSH
- paměť účinky léků MeSH
- protein FMRP metabolismus genetika MeSH
- receptory kanabinoidní * metabolismus MeSH
- receptory spřažené s G-proteiny metabolismus MeSH
- rozpoznávání (psychologie) * účinky léků MeSH
- simulace molekulového dockingu MeSH
- syndrom fragilního X * farmakoterapie metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Hypofunctioning of NMDA receptors, and the resulting shift in the balance between excitation and inhibition, is considered a key process in the pathophysiology of schizophrenia. One important manifestation of this phenomenon is changes in neural oscillations, those above 30 Hz (i.e., gamma-band oscillations), in particular. Although both preclinical and clinical studies observed increased gamma activity following acute administration of NMDA receptor antagonists, the relevance of this phenomenon has been recently questioned given the reduced gamma oscillations typically observed during sensory and cognitive tasks in schizophrenia. However, there is emerging, yet contradictory, evidence for increased spontaneous gamma-band activity (i.e., at rest or under baseline conditions). Here, we use the sub-chronic phencyclidine (PCP) rat model for schizophrenia, which has been argued to model the pathophysiology of schizophrenia more closely than acute NMDA antagonism, to investigate gamma oscillations (30-100 Hz) in the medial prefrontal cortex of anesthetized animals. While baseline gamma oscillations were not affected, oscillations induced by train stimulation of the posterior dorsal CA1 (pdCA1) field of the hippocampus were enhanced in PCP-treated animals (5 mg/kg, twice daily for 7 days, followed by a 7-day washout period). This effect was reversed by pharmacological enhancement of endocannabinoid levels via systemic administration of URB597 (0.3 mg/kg), an inhibitor of the catabolic enzyme of the endocannabinoid anandamide. Intriguingly, the pharmacological blockade of CB1 receptors by AM251 unmasked a reduced gamma oscillatory activity in PCP-treated animals. The findings are consistent with the observed effects of URB597 and AM251 on behavioral deficits reminiscent of the symptoms of schizophrenia and further validate the potential for cannabinoid-based drugs as a treatment for schizophrenia.
- MeSH
- amidohydrolasy * antagonisté a inhibitory metabolismus MeSH
- antagonisté excitačních aminokyselin farmakologie aplikace a dávkování MeSH
- benzamidy * farmakologie MeSH
- endokanabinoidy metabolismus MeSH
- fencyklidin * farmakologie MeSH
- gama rytmus EEG fyziologie účinky léků MeSH
- karbamáty * farmakologie MeSH
- krysa rodu rattus MeSH
- kyseliny arachidonové metabolismus farmakologie MeSH
- modely nemocí na zvířatech MeSH
- piperidiny * farmakologie MeSH
- polynenasycené alkamidy metabolismus farmakologie MeSH
- potkani Sprague-Dawley MeSH
- prefrontální mozková kůra účinky léků metabolismus patofyziologie MeSH
- pyrazoly farmakologie MeSH
- schizofrenie * patofyziologie metabolismus farmakoterapie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Anandamide (AEA) is an important modulator of nociception in the spinal dorsal horn, acting presynaptically through Cannabinoid (CB1) and Transient receptor potential vanilloid (TRPV1) receptors. The role of AEA (1 μM, 10 μM, and 30 μM) application on the modulation of nociceptive synaptic transmission under control and inflammatory conditions was studied by recording miniature excitatory postsynaptic currents (mEPSCs) from neurons in spinal cord slices. Inhibition of the CB1 receptors by PF514273, TRPV1 by SB366791, and the fatty acid amide hydrolase (FAAH) by URB597 was used. Under naïve conditions, the AEA application did not affect the mEPSCs frequency (1.43±0.12 Hz) when all the recorded neurons were considered. The mEPSC frequency increased (180.0±39.2%) only when AEA (30 μM) was applied with PF514273 and URB597. Analysis showed that one sub-population of neurons had synaptic input inhibited (39.1% of neurons), the second excited (43.5%), whereas 8.7% showed a mixed effect and 8.7% did not respond to the AEA. With inflammation, the AEA effect was highly inhibitory (72.7%), while the excitation was negligible (9.1%), and 18.2% were not modulated. After inflammation, more neurons (45.0%) responded even to low AEA by mEPSC frequency increase with PF514273/URB597 present. AEA-induced dual (excitatory/inhibitory) effects at the 1st nociceptive synapse should be considered when developing analgesics targeting the endocannabinoid system. These findings contrast the clear inhibitory effects of the AEA precursor 20:4-NAPE application described previously and suggest that modulation of endogenous AEA production may be more favorable for analgesic treatments.
- MeSH
- amidohydrolasy MeSH
- analgetika farmakologie MeSH
- benzamidy * MeSH
- endokanabinoidy * farmakologie MeSH
- karbamáty * MeSH
- kyseliny arachidonové * MeSH
- lidé MeSH
- nocicepce * MeSH
- polynenasycené alkamidy farmakologie MeSH
- zadní rohy míšní MeSH
- zánět farmakoterapie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Transient receptor potential ion channel, vanilloid subfamily, type 1 (TRPV1) cation channel, and cannabinoid receptor 1 (CB1) are essential in the modulation of nociceptive signaling in the spinal cord dorsal horn that underlies different pathological pain states. TRPV1 and CB1 receptors share the endogenous agonist anandamide (AEA), produced from N-arachidonoylphosphatidylethanolamine (20:4-NAPE). We investigated the effect of the anandamide precursor 20:4-NAPE on synaptic activity in naive and inflammatory conditions. Patch-clamp recordings of miniature excitatory postsynaptic currents (mEPSCs) from superficial dorsal horn neurons in rat acute spinal cord slices were used. Peripheral inflammation was induced by subcutaneous injection of carrageenan. Under naive conditions, mEPSCs frequency (0.96 ± 0.11 Hz) was significantly decreased after 20 μM 20:4-NAPE application (55.3 ± 7.4%). This 20:4-NAPE-induced inhibition was blocked by anandamide-synthesizing enzyme N-acyl phosphatidylethanolamine phospholipase D (NAPE-PLD) inhibitor LEI-401. In addition, the inhibition was prevented by the CB1 receptor antagonist PF 514273 (0.2 μM) but not by the TRPV1 receptor antagonist SB 366791 (10 μM). Under inflammatory conditions, 20:4-NAPE (20 μM) also exhibited a significant inhibitory effect (74.5 ± 8.9%) on the mEPSCs frequency that was prevented by the TRPV1 receptor antagonist SB 366791 but not by PF 514273 application. Our results show that 20:4-NAPE application has a significant modulatory effect on spinal cord nociceptive signaling that is mediated by both TRPV1 and CB1 presynaptic receptors, whereas peripheral inflammation changes the underlying mechanism. The switch between TRPV1 and CB1 receptor activation by the AEA precursor 20:4-NAPE during inflammation may play an important role in nociceptive processing, hence the development of pathological pain.
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Human amniotic and amniochorionic membranes (AM, ACM) represent the most often used grafts accelerating wound healing. Palmitoylethanolamide, oleoylethanolamide and anandamide are endogenous bioactive lipid molecules, generally referred as N-acylethanolamines. They express analgesic, nociceptive, neuroprotective and anti-inflammatory properties. We assessed the distribution of these lipid mediators in placental tissues, as they could participate on analgesic and wound healing effect of AM/ACM grafts. METHODS: Seven placentas were collected after caesarean delivery and fresh samples of AM, ACM, placental disc, umbilical cord, umbilical serum and vernix caseosa, and decontaminated samples (antibiotic solution BASE 128) of AM and ACM have been prepared. Ultra-high-performance liquid chromatography-tandem mass spectrometry was used for N-acylethanolamines analysis. RESULTS: N-acylethanolamines were present in all studied tissues, palmitoylethanolamide being the most abundant and the anandamide the least. For palmitoylethanolamide the maximum average concentration was detected in AM (350.33 ± 239.26 ng/g), while oleoylethanolamide and anandamide were most abundant in placenta (219.08 ± 79.42 ng/g and 30.06 ± 7.77 ng/g, respectively). Low levels of N-acylethanolamines were found in serum and vernix. A significant increase in the levels of N-acylethanolamines (3.1-3.6-fold, P < 0.001) was observed in AM when the tissues were decontaminated using antibiotic solution. The increase in decontaminated ACM was not statistically significant. CONCLUSIONS: The presence of N-acylethanolamines, particularly palmitoylethanolamide in AM and ACM allows us to propose these lipid mediators as the likely factors responsible for the anti-hyperalgesic, but also anti-inflammatory and neuroprotective, effects of AM/ACM grafts in wound healing treatment. The increase of N-acylethanolamines levels in AM and ACM after tissue decontamination indicates that tissue processing is an important factor in maintaining the analgesic effect.
- MeSH
- analgetika MeSH
- endokanabinoidy * MeSH
- ethanolaminy MeSH
- lidé MeSH
- placenta * MeSH
- polynenasycené alkamidy MeSH
- těhotenství MeSH
- Check Tag
- lidé MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Spontaneous preterm birth (sPTB) is a major cause of perinatal morbidity and mortality, even in developed countries. Prediction of sPTB is therefore a valuable tool to reduce the associated risks. The current standard for the prediction of sPTB consists, in addition to anamnestic data, of previous sPTB and previous second trimester miscarriage, measurement of cervical length by transvaginal ultrasound (TVU CL) together with assessment of fetal fibronectin levels in cervicovaginal fluid. Other evaluation parameters, such as the level of endocannabinoids in the pregnant woman's blood, could increase the sensitivity of this management. Endocannabinoids (eCBs) are a part of the endocannabinoid system (ECS); out of them anandamide (arachidonoyl-ethanolamide, AEA), in particular, plays an important role in the regulation of pregnancy and childbirth. We present the protocol for an open, non-randomized study to evaluate concentrations of AEA and other endocannabinoids: 2 linoleoylglycerol (2-AG), 2 linoleoylglycerol (2-LG), 2 oleoylglycerol (2-OG), and 2 arachidonoyldopamine (2-ADOPA or also NADA) in the blood of pregnant women as potential predictors of sPTB. In a total of 230 women with a history of sPTB or miscarriage, eCBs levels between 22 and 28 weeks of gestation will be assessed from maternal blood, in addition to the standard procedure. The aim of the study is to determine the relationship between blood concentrations of the endocannabinoids tested and the risk of sPTB. The results of this study will describe the prognostic significance of maternal blood eCBs levels for sPTB, and could subsequently enable improved screening programs for early identification of sPTB.
- MeSH
- druhý trimestr těhotenství MeSH
- endokanabinoidy MeSH
- lidé MeSH
- novorozenec MeSH
- předčasný porod * diagnóza MeSH
- samovolný potrat * MeSH
- těhotenství MeSH
- Check Tag
- lidé MeSH
- novorozenec MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Cíl studie: Přehled současných poznatků o endokanabinoidech ve vztahu k těhotenství a porodu a jejich potenciálu pro predikci předčasného porodu. Metodika: Přehled publikované literatury k danému tématu použitím databáze PubMed. Výsledky: Kanabinoidní systém hraje roli při vývoji a implantaci blastocysty, embrya, placentaci a u porodu člověka. V lidských tkáních byla identifikována řada zástupců endokanabinoidů, avšak ve vztahu k lidské reprodukci jsou dosud nejvýznamnější anandamid a 2-arachidonoglycerol. Anandamid a jeho následná metabolická přeměna stojí na počátku signální kaskády, která úzce souvisí s délkou těhotenství. Účinky anandamidu závisí na jeho metabolické cestě a aktivitě enzymů, které zajišťují jeho přeměnu. Výsledkem je buď zvýšená tvorba prostaglandinů, nebo prostamidů, s protichůdnými účinky na průběh těhotenství. Užívání exokanabinoidů vč. konopí v období těhotenství ovlivňuje organizmus matky i vývoj plodu na mnoha úrovních a může vést k nepříznivým důsledkům vč. zvýšení rizika předčasného porodu. Závěr: Měření koncentrací anandamidu a stanovení rozmezí poměru prostaglandinů vůči prostamidům pro délku těhotenství by mohlo být užitečným nástrojem při hodnocení rizika předčasného porodu.
Objective: In this paper, we summarize the role of the endocannabinoid system in relation to pregnancy and childbirth and its potential for diagnosis of preterm birth. Methods: Review of articles in peer-reviewed journals using the PubMed database. Results: Endocannabinoid system plays a significant role in embryo development, transport and implantation as well as in placentation. It consists of numerous endogenous ligands; however, in relation to pregnancy there are mainly two studied representatives: anandamide and 2-arachidonoylglycerol. There is increasing evidence, in addition to early pregnancy events, that anandamide plays a regulatory role in pregnancy maintenance and the timing of labour. The activity of anandamide depends on its metabolic pathway and the enzymatic activity that ensures its conversion. Ultimately, changes in anandamide concentration lead to increased production of prostaglandins or prostamides, with inverse effects on pregnancy. The abuse of exogenous cannabinoids in pregnancy has substantial impact on the unborn child in many ways and may result in detrimental effects including preterm birth. Conclusion: Measuring anandamide concentration and the prostaglandin to prostamide ratio could be a useful tool in assessing the risk of preterm birth.
- MeSH
- endokanabinoidy * škodlivé účinky MeSH
- lidé MeSH
- porod MeSH
- těhotenství * MeSH
- Check Tag
- lidé MeSH
- těhotenství * MeSH
- ženské pohlaví MeSH
- Publikační typ
- přehledy MeSH
Cíl: Přehled aktuálních poznatků o endokanabinoidním systému člověka. Endokanabinoidní systém je tvořen kanabinoidními receptory 1 a 2, ligandy těchto receptorů, zejména dvěma „klasickými“ endokanabinoidy N-arachidonoylethanolaminem (anandamid) a 2-arachidonoyl-glycerolem a transportními systémy. Transportní systémy zajišťují vstup endokanabinoidů do buněk, kde dochází k jejich odbourávání cestou hydrolázy amidů mastných kyselin nebo lipázy pro monoacyl-glyceroly. Endokanabinoidní systém reguluje řadu fyziologických nebo patologických stavů. O aktuálním zájmu o studium těchto regulací svědčí v poslední době explozivní nárůst počtu publikovaných prací. Porucha regulace endokanabinoidního systému je možnou příčinou řady onemocnění. Může k ní docházet jednak při genetickém polymorfizmu jejích jednotlivých komponent, ale také při terapii některými léky nebo přírodními látkami, typicky kanabinoidy. Kvůli širokému překryvu regulací fyziologických funkcí endokanabinoidním systémem je vyvíjeno značné množství léků, jejichž cílem je úprava dysregulace endokanabinoidního systému. Závěr: Endokanabinoidní systém patří v organizmu člověka mezi nejvýznamnější regulační systémy s velmi širokým zásahem do fyziologických a patologických stavů. Výsledné konkrétní regulace jsou průsečíkem souhry mnoha enzymů, které se účastní tvorby a odbourávání endokanabinoidů, transportních systémů, které se účastní vstupu endokanabinoidů do buněk, kanabinoidních receptorů a exogenních kanabinoidů, resp. přírodních látek působících na různých místech endokanabinoidního systému. Znalosti v této oblasti mohou přispět ke zlepšení zdravotní péče a ke zvýšení bezpečnosti jejího poskytování.
Objective: Overview of current knowledge in the field of the endocannabinoid system with emphasis on the relationships between endocannabinoids and exocannabinoids. The endocannabinoid system consists of cannabinoid receptors 1 and 2, ligands of these receptors, especially two „classical“ endocannabinoids N-arachidonoylethanolamine (anandamide) and 2-arachidonoyl-glycerol. Transport systems that ensure the entry of endocannabinoids into cells, where they are degraded by fatty acid amide hydrolase or monoacylglycerol lipase. The endocannabinoid system is a signaling pathway for the regulation of a number of physiological or pathological conditions. So far, it is one of the less explored ways of regulation, as evidenced by the recent explosive increase in the number of published works. Dysregulation of endocannabinoid systems is a possible cause of many diseases. It can occur both in the genetic polymorphism of its individual components, but also in therapy with certain drugs or natural substances, typically cannabinoids. Due to the wide overlap of the regulation of physiological functions by the endocannabinoid system, a considerable number of drugs are being developed, the aim of which is to correct the dysregulation of the endocannabinoid system. Conclusion: The endocannabinoid system is one of the most important regulatory systems with a very broad intervention in physiological and pathological conditions. The resulting specific regulations intersect the interplay of many enzymes involved in the production and degradation of endocannabinoids, transport systems involved in the entry of endocannabinoids into cells, cannabinoid receptors and exogenous cannabinoids, or natural substances acting at various sites in the endocannabinoid system. Knowledge in this area can contribute to improving health care and increasing the safety of its provision.
- MeSH
- endokanabinoidy * MeSH
- kanabinoidy * MeSH
- lidé MeSH
- receptory kanabinoidní MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH