Tag Archives: cannabinoid receptors

Cannabinoid 2 (CB2) receptor agonism reduces lithium chloride-induced vomiting in Suncus murinus and nausea-induced conditioned gaping in rats.

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“We aimed to investigate the potential anti-emetic and anti-nausea properties of targeting the cannabinoid 2 (CB2) receptor.

We investigated the effect of the selective CB2 agonist, HU-308, on lithium chloride- (LiCl) induced vomiting in Suncus murinus (S. murnius) and conditioned gaping (nausea-induced behaviour) in rats.

These findings are the first to demonstrate the ability of a selective CB2 receptor agonist to reduce nausea in animal models, indicating that targeting the CB2 receptor may be an effective strategy, devoid of psychoactive effects, for managing toxin-induced nausea and vomiting.”

http://www.ncbi.nlm.nih.gov/pubmed/27263826

CB1 Receptor Antagonism Prevents Long-Term Hyperexcitability after Head Injury by Regulation of Dynorphin-KOR System and mGluR5 in Rat Hippocampus.

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“Both endocannabinoids and dynorphin are feedback messengers in nervous system that act at the presynaptic nerve terminal to inhibit transmitter release. Many studies showed the cannabinoid-opioid cross-modulation in antinociception, hypothermia, sedation and reward.

The aim of this study was to assess the influence of early application of cannabinoid type 1 (CB1) receptor antagonism SR141716A after brain injury on dynorphin-κ opioid receptor (KOR) system and the expression of metabotropic glutamate receptors (mGluRs) in a rat model of fluid percussion injury (FPI).

Firstly, seizure latency induced by pentylenetetrazole was significantly prolonged 6 weeks after brain injury in group of SR141716A treatment. Then, PCR and western blot showed that SR141716A inhibited the long-term up-regulation of CB1 receptors in hippocampus. However, SR141716A resulted in long-term potentiation of dynorphin release and did not influence the up-regulation of KOR in hippocampus after brain injury. Furthermore, SR141716A reverse the overexpression of mGluR5 in the late stage of brain injury.

We propose that during the induction of epileptogenesis after brain injury, early application of CB1 receptor antagonism could prevent long-term hyperexcitability by up-regulation of dynorphin-KOR system and prevention of mGluR5 induced epileptogenesis in hippocampus.”

http://www.ncbi.nlm.nih.gov/pubmed/27262683

Gastric acid inhibitory and gastric protective effects of Cannabis and cannabinoids.

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“Cannabis sativa has long been known for its psychotropic effect. Only recently with the discovery of the cannabinoid receptors, their endogenous legends and the enzymes responsible for their synthesis and degradation, the role of this ‘endocannabinoid system’ in different pathophysiologic processes is beginning to be delineated.

There is evidence that CB1 receptor stimulation with synthetic cannabinoids or Cannabis sativa extracts rich in Δ9-tetrahydrocannabinol inhibit gastric acid secretion in humans and experimental animals.

This is specially seen when gastric acid secretion is stimulated by pentagastrin, carbachol or 2-deoxy-d-glucose.

Cannabis and/or cannabinoids protect the gastric mucosa against noxious challenge with non-steroidal anti-inflammatory drugs, ethanol as well as against stress-induced mucosal damage.

Cannabis/cannabinoids might protect the gastric mucosa by virtue of its antisecretory, antioxidant, anti-inflammatory, and vasodilator properties.”

http://www.ncbi.nlm.nih.gov/pubmed/27261847

Cannabinoid receptor-2 stimulation suppresses neuroinflammation by regulating microglial M1/M2 polarization through the cAMP/PKA pathway in an experimental GMH rat model.

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“Excessive inflammatory responses are involved in secondary brain injury during germinal matrix hemorrhage (GMH). The process of microglial polarization to the pro-inflammatory M1 or anti-inflammatory M2 phenotypes is considered to occur in a major immunomodulatory manner during brain inflammation.

We previously found that cannabinoid receptor-2 (CB2R) stimulation attenuated microglial accumulation and brain injury following experimental GMH.

Herein, we investigated the effects of CB2R stimulation on neuroinflammation after experimental GMH and the potential mechanisms that mediate M1/M2 microglial phenotype regulation.

This is the first study to propose that promotion of microglial M2 polarization through the cAMP/PKA pathway participates in the CB2R-mediated anti-inflammatory effects after GMH induction.

The results will help to further understand the mechanisms that underlie neuroprotection by CB2R in GMH and promote clinical translational research for CB2R agonists.”

http://www.ncbi.nlm.nih.gov/pubmed/27261088

Anandamide transporter-mediated regulation of the micturition reflex in urethane-anesthetized rats.

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“The aim of this study was to investigate the effects of an anandamide transporter inhibitor that can increase endogenous anandamide concentration on the micturition reflex in urethane-anesthetized rats.

These results suggest that anandamide, an endogenous CB ligand, can modulate the micturition reflex and that anandamide transporters play an important role in this modulation. In urethane-anesthetized rats, inhibition of the uptake of anandamide can inhibit the micturition reflex and these inhibitory effects of VDM11 are at least in part mediated by the CB1 receptor.”

http://www.ncbi.nlm.nih.gov/pubmed/27256398

Clinical Effects of Synthetic Cannabinoid Receptor Agonists Compared with Marijuana in Emergency Department Patients with Acute Drug Overdose.

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“Synthetic cannabinoid receptor agonists (SCRAs) are heterogeneous compounds originally intended as probes of the endogenous cannabinoid system or as potential therapeutic agents.

In the first clinical study comparing the adverse effects of SCRA overdose vs. marijuana controls in an ED population, we found that SCRA overdoses had significantly pronounced neurotoxicity and cardiotoxicity compared with marijuana.”

http://www.ncbi.nlm.nih.gov/pubmed/27255136

Cannabinoid Receptors Are Overexpressed in CLL but of Limited Potential for Therapeutic Exploitation.

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“The cannabinoid receptors 1 and 2 (CNR1&2) are overexpressed in a variety of malignant diseases and cannabinoids can have noteworthy impact on tumor cell viability and tumor growth.

Patients diagnosed with chronic lymphocytic leukemia (CLL) present with very heterogeneous disease characteristics translating into highly differential risk properties.

To meet the urgent need for refinement in risk stratification at diagnosis and the search for novel therapies we studied CNR expression and response to cannabinoid treatment in CLL.

Expression levels of CNR1&2 were determined in 107 CLL patients by real-time PCR and analyzed with regard to prognostic markers and survival.

In contrast to other tumor entities, our data suggest a limited usability of cannabinoids for CLL therapy. Nonetheless, we could define CNR1 mRNA expression as novel prognostic marker.”

http://www.ncbi.nlm.nih.gov/pubmed/27248492

Western Blotting of the Endocannabinoid System.

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“Measuring expression levels of G protein-coupled receptors (GPCRs) is an important step for understanding the distribution, function, and regulation of these receptors. A common approach for detecting proteins from complex biological systems is Western blotting. In this chapter, we describe a general approach to Western blotting protein components of the endocannabinoid system using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and nitrocellulose membranes, with a focus on detecting type 1 cannabinoid (CB1) receptors. When this technique is carefully used, specifically with validation of the primary antibodies, it can provide quantitative information on protein expression levels. Additional information can also be inferred from Western blotting such as potential posttranslational modifications that can be further evaluated by specific analytical techniques.”

http://www.ncbi.nlm.nih.gov/pubmed/27245910

Quantitation of Plasma Membrane (G Protein-Coupled) Receptor Trafficking in Cultured Cells.

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“Measuring the functional behavior of G protein-coupled receptors (GPCRs) has been a major focus of academic and pharmaceutical research for many decades. These efforts have led to the development of many assays to measure the downstream effects of ligand binding on receptor activity. In this chapter, we describe an internalization/recycling assay that can be used to track changes in receptor number at the plasma membrane. Used in concert with other assays, this antibody-based technique can provide important information on GPCR activation by receptor-specific ligands.”

http://www.ncbi.nlm.nih.gov/pubmed/27245911

Assay of Endocannabinoid Oxidation by Cyclooxygenase-2.

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“The endocannabinoids, 2-arachidonoylglycerol (2-AG) and arachidonylethanolamide (AEA), are endogenous ligands for the cannabinoid receptors (CB1 and CB2) and are implicated in a wide array of physiological processes. These neutral arachidonic acid (AA) derivatives have been identified as efficient substrates for the second isoform of the cyclooxygenase enzyme (COX-2). A diverse family of prostaglandin glycerol esters (PG-Gs) and prostaglandin ethanolamides (PG-EAs) is generated by the action of COX-2 (and downstream prostaglandin synthases) on 2-AG and AEA. As the biological importance of the endocannabinoid system becomes more apparent, there is a tremendous need for robust, sensitive, and efficient analytical methodology for the endocannabinoids and their metabolites. In this chapter, we describe methodology suitable for carrying out oxygenation of endocannabinoids by COX-2, and analysis of products of endocannabinoid oxygenation by COX-2 and of endocannabinoids themselves from in vitro and cell assays.”

http://www.ncbi.nlm.nih.gov/pubmed/27245906