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Query: UNIPROT:P21554 (cannabinoid receptor)
 3,582 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Antibodies designed to recognize a 74 amino acid sequence of the N- or C-terminal domain of the rat CB1 cannabinoid receptor detected a 58 kDa protein in immunoblots of brain and various cells known to express the CB1 cannabinoid receptor. A human B-lymphoblastoid cell line and macrophage-like cells from neonatal rat brain were also positive for CB1 receptor-like immunoreactivity. Immunocytochemical analysis performed with isolated Fab fragments showed surface staining in NG108-15 cells and brain macrophage like cells which also express MHC class II antigens. The data suggest a plausible role for CB1 receptors in the immune function of brain.
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PMID:Expression of the CB1 cannabinoid receptor in macrophage-like cells from brain tissue: immunochemical characterization by fusion protein antibodies. 952 41

1. The purpose of these experiments was to determine whether or not the endothelium-dependent hyperpolarizations of the vascular smooth muscle cells (observed in the presence of inhibitors of nitric oxide synthase and cyclo-oxygenase) can be attributed to the production of an endogenous cannabinoid. 2. Membrane potential was recorded in the guinea-pig carotid, rat mesenteric and porcine coronary arteries by intracellular microelectrodes. 3. In the rat mesenteric artery, the cannabinoid receptor antagonist, SR 141716 (1 microM), did not modify either the resting membrane potential of smooth muscle cells or the endothelium-dependent hyperpolarization induced by acetylcholine (1 microM) (17.3 +/- 1.8 mV, n = 4 and 17.8 +/- 2.6 mV, n = 4, in control and presence of SR 141716, respectively). Anandamide (30 microM) induced a hyperpolarization of the smooth muscle cells (12.6 +/- 1.4 mV, n = 13 and 2.0 +/- 3.0 mV, n = 6 in vessels with and without endothelium, respectively) which could not be repeated in the same tissue, whereas acetylcholine was still able to hyperpolarize the preparation. The hyperpolarization induced by anandamide was not significantly influenced by SR 141716 (1 microM). HU-210 (30 microM), a synthetic CB1 receptor agonist, and palmitoylethanolamide (30 microM), a CB2 receptor agonist, did not influence the membrane potential of the vascular smooth muscle cells. 4. In the rat mesenteric artery, the endothelium-dependent hyperpolarization induced by acetylcholine (1 microM) (19.0 +/- 1.7 mV, n = 6) was not altered by glibenclamide (1 microM; 17.7 +/- 2.3 mV, n = 3). However, the combination of charybdotoxin (0.1 microM) plus apamin (0.5 microM) abolished the acetylcholine-induced hyperpolarization and under these conditions, acetylcholine evoked a depolarization (7.7 +/- 2.7 mV, n = 3). The hyperpolarization induced by anandamide (30 microM) (12.6 +/- 1.4 mV, n = 13) was significantly inhibited by glibenclamide (4.0 +/- 0.4 mV, n = 4) but not significantly affected by the combination of charybdotoxin plus apamin (17.3 +/- 2.3 mV, n = 4). 5. In the guinea-pig carotid artery, acetylcholine (1 microM) evoked endothelium-dependent hyperpolarization (18.8 +/- 0.7 mV, n = 15). SR 141716 (10 nM to 10 microM), caused a direct, concentration-dependent hyperpolarization (up to 10 mV at 10 microM) and a significant inhibition of the acetylcholine-induced hyperpolarization. Anandamide (0.1 to 3 microM) did not influence the membrane potential. At a concentration of 30 microM, the cannabinoid agonist induced a non-reproducible hyperpolarization (5.6 +/- 1.3 mV, n = 10) with a slow onset. SR 141716 (1 microM) did not affect the hyperpolarization induced by 30 microM anandamide (5.3 +/- 1.5 mV, n = 3). 6. In the porcine coronary artery, anandamide up to 30 microM did not hyperpolarize or relax the smooth muscle cells. The endothelium-dependent hyperpolarization and relaxation induced by bradykinin were not influenced by SR 141716 (1 microM). 7. These results indicate that the endothelium-dependent hyperpolarizations, observed in the guinea-pig carotid, rat mesenteric and porcine coronary arteries, are not related to the activation of cannabinoid CB1 receptors.
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PMID:Cannabinoid CB1 receptor and endothelium-dependent hyperpolarization in guinea-pig carotid, rat mesenteric and porcine coronary arteries. 953 27

The involvement of cannabinoid processes in positive reinforcement was studied using an unbiased, one-compartment, conditioned place preference (CPP) procedure in rats. This was achieved by examining the ability of the selective antagonist of the CB1 cannabinoid receptor subtype, SR 141716, to counteract the CPP supported by classical reinforcers. The acquisition of CPP induced by cocaine (2 mg/kg), morphine (4 mg/kg) and food (standard chow and sucrose pellets) was dose-dependently blocked by pre-pairing administration of SR 141716 (0.03-3 mg/kg). However, SR 141716 (up to 10 mg/kg) did not significantly counteract the expression of cocaine-induced CPP. On the other hand, the synthetic CB receptor agonist, WIN 55212-2 (0.3-1 mg/kg), established a robust place aversion (CPA), as already described with other agonists, and CPP was never observed, even at 100-fold lower doses. The aversive effect of WIN 55212-2 was reversed by SR 141716 (0.3-1 mg/kg), suggesting that it was accounted for by the stimulation of CB1 receptors. These findings indicate that, on their own, CB receptor agonists are unable to generate the processes necessary to induce a pleasurable state in animals, as assessed in place conditioning procedures. Nevertheless, a cannabinoid link may be involved in the neurobiological events, allowing the perception of the rewarding value of various kinds of reinforcers. However, a permanent endogenous cannabinoid tone seems unlikely to be necessary to ensure the organism a basal hedonic level since, given alone, SR 141716 supported neither CPP nor CPA.
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PMID:Involvement of central cannabinoid (CB1) receptors in the establishment of place conditioning in rats. 953 55

Central antinociceptive effects of cannabinoids have been well documented. However, relatively little is known about the peripheral effects of the cannabinoids on inflammation. In the present study, we evaluated the effects of peripherally administered cannabinoids on three indices of inflammation: carrageenan-induced thermal hyperalgesia, carrageenan-induced edema, and capsaicin-induced plasma extravasation. In addition, we determined the effect of cannabinoids on capsaicin-evoked neuropeptide release from isolated rat hindpaw skin. Our results indicate that cannabinoids produce antihyperalgesia via interaction with a peripheral CB1 receptor. Peripheral, but not systemic, administration of 0.01 ng anandamide inhibited the induction of hyperalgesia. Peripheral administration of anandamide also attenuated hyperalgesia after its development via interaction with the CB1 cannabinoid receptor subtype as indicated by its reversal with the CB1 receptor antagonist SR 141716A. Additionally, peripheral, but not systemic, administration of 0.01 ng anandamide inhibited edema. Peripherally administered cannabinoids also interacted with CB1 receptors to inhibit capsaicin-evoked plasma extravasation into the hindpaw. One potential mechanism for the anti-inflammatory actions of the cannabinoids is the inhibition of neurosecretion from the peripheral terminals of nociceptive primary afferent fibers. This hypothesis is supported by the finding that anandamide inhibited capsaicin-evoked release of calcitonin gene-related peptide from isolated hindpaw skin. Collectively, these results indicate that cannabinoids reduce inflammation via interaction with a peripheral CB1 receptor. A potential mechanism for this effect is the inhibition of neurosecretion from capsaicin-sensitive primary afferent fibers.
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PMID:Cannabinoids reduce hyperalgesia and inflammation via interaction with peripheral CB1 receptors. 953 80

2-Arachidonyl-glycerol (2-Ara-Gl) recently was identified as a putative endogenous ligand for cannabinoid receptor types CB1 and CB2 by competitive binding. More recent immune function assays demonstrated that 2-Ara-Gl possessed immunomodulatory activity. Because several plant-derived cannabinoids inhibit interleukin-2 (IL-2) expression, 2-Ara-Gl was investigated for its ability to modulate this cytokine. The direct addition of 2-Ara-Gl to mouse splenocyte cultures suppressed phorbol-12-myristate-13-acetate plus ionomycin-induced IL-2 secretion and steady state mRNA expression in a dose-dependent manner. 2-Ara-Gl also produced a marked inhibition of IL-2 promotor activity as determined by transient transfection of EL4.IL-2 cells with a pIL-2-CAT construct. 2-Ara-Gl at 5, 10, 20, and 50 microM suppressed phorbol-12-myristate-13-acetate plus ionomycin-induced IL-2 promotor activity by 18%, 28%, 39%, and 54%, respectively. To further characterize the mechanism for the transcriptional regulation of IL-2 by 2-Ara-Gl, the DNA-binding activity of transcription factors, nuclear factor of activated T cells (NF-AT), nuclear factor for immunoglobulin kappa chain in B cells (NF-kappa B/Rel), activator protein-1(AP-1), octamer, and cAMP-response element binding protein was evaluated by electrophoretic mobility shift assay in mouse splenocytes. In addition, a reporter gene expression system for p(NF-kappa B)3-CAT, p(NF-AT)3-CAT, and p(AP-1)3-CAT was used in transiently transfected EL4.IL-2 cells to determine the effect of 2-Ara-Gl on promoter activity for each of the specific transcription factors. 2-Ara-Gl reduced both the NF-AT-binding and promoter activity in a dose-dependent manner and, to a lesser degree, NF-kappa B/Rel-binding and promoter activity. No significant effect was observed on octamer- and cAMP-response element-binding activity. AP-1 DNA-binding activity was not inhibited by 2-Ara-Gl, but a modest inhibition of promoter activity was observed.
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PMID:Suppression of interleukin-2 by the putative endogenous cannabinoid 2-arachidonyl-glycerol is mediated through down-regulation of the nuclear factor of activated T cells. 954 58

The effect of anandamide, an endogenous ligand for central (CB1) and peripheral (CB2) cannabinoid receptors, was investigated on the growth of the murine IL-6-dependent lymphoid cell line B9 and the murine IL-3-dependent myeloblastic cell line FDC-P1. In conditions of low serum level, anandamide potentiated the growth of both cytokine-dependent cell lines. Comparison with other fatty acid cannabinoid ligands such as (R)-methanandamide, a ligand with improved selectivity for the CB1 receptor, or palmitylethanolamide, an endogenous ligand for the CB2 receptor, showed a very similar effect, suggesting that cell growth enhancement by anandamide or its analogs could be mediated through either receptor subtype. However, several lines of evidence indicated that this growth-promoting effect was cannabinoid receptor-independent. First, the potent synthetic cannabinoid agonist CP 55940, which displays high affinity for both receptors, was inactive in this model. Second, SR 141716A and SR 144528, which are potent and specific antagonists of CB1 and CB2 receptors respectively, were unable, alone or in combination, to block the anandamide-induced effect. Third, inactivation of both receptors by pretreatment of cells with pertussis toxin did not affect the potentiation of cell growth by anandamide. These data demonstrated that neither CB1 nor CB2 receptors were involved in the anandamide-induced effect. Moreover, using CB2-transfected Chinese hamster ovary cells, we demonstrated that after complete blockade of the receptors by the specific antagonist SR 144528, anandamide was still able to strongly stimulate a mitogen-activated protein (MAP) kinase activity, clearly indicating that the endogenous cannabinoid can transduce a mitogenic signal in the absence of available receptors. Finally, arachidonic acid, a structurally related compound and an important lipid messenger without known affinity for cannabinoid receptors, was shown to trigger MAP kinase activity and cell growth enhancement similar to those observed with anandamide. These findings provide clear evidence for a functional role of anandamide in activating a signal transduction pathway leading to cell activation and proliferation via a non-cannabinoid receptor-mediated process.
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PMID:The endogenous cannabinoid anandamide is a lipid messenger activating cell growth via a cannabinoid receptor-independent pathway in hematopoietic cell lines. 956 6

Cannabinoids are a class of compound found in marijuana which have been known for their therapeutic and psychoactive properties for at least 4000 years. Isolation of the active principle in marijuana, delta9-THC, provided the lead structure in the development of highly potent congeners which were used to probe for the mechanism of marijuana action. Cannabinoids were shown to bind to selective binding sites in brain tissue thereby regulating second messenger formation. Such studies led to the cloning of three cannabinoid receptor subtypes, CB1, CB2, and CB1A all of which belong to the superfamily of G protein-coupled plasma membrane receptors. Analogous to the discovery of endogenous opiates, isolation of cannabinoid receptors provided the appropriate tool to isolate an endogenous cannabimimetic eicosanoid, anandamide, from porcine brain. Recent studies indicate that anandamide is a member of a family of fatty acid ethanolamides that may represent a novel class of lipid neurotransmitters. This review discusses recent progress in cannabinoid research with a focus on the receptors for delta9-THC, their coupling to second messenger responses, and the endogenous lipid cannabimimetic, anandamide.
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PMID:Cannabinoid receptors and their endogenous agonist, anandamide. 956 94

The effect of cannabinoid receptor activation and blockade on the propulsive activity in the mouse small intestine was assessed in the present study by measuring the transit of an orally administered, non-absorbable marker. The cannabinoid receptor agonist WIN 55,212-2 (R(+)-[2,3-dihydro-5-methyl-3[(morpholinyl)methyl]pyrrolo[1,2,3-de-1, 4benzoxazin-yl]-(1-naphthalenyl)methanone mesylate) inhibited, while the selective cannabinoid CB1 receptor antagonist SR 141716A (N-piperidino-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-3-pyraz ole-carboxamide) stimulated the marker transit. Furthermore, a per se non-effective dose of SR 141716A reversed WIN 55,212-2-induced reduction of the transit. The results of the present study suggest a role for cannabinoid CB1 receptors in the control of propulsive activity in the mouse small intestine.
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PMID:Cannabinoid modulation of intestinal propulsion in mice. 957 Apr 50

Cannabinoid receptors are members of the superfamily of G protein-coupled receptors. Their activation has previously been shown to stimulate guanosine 5'-O-(3-[35S]thio)-triphosphate ([35S]GTP gamma S) binding in a range of brain regions using both membrane preparations and autoradiography. This study evaluates the activities of structurally diverse cannabinoid receptor ligands in the GTP gamma S binding assay, comparing the relationship between receptor binding and activation and also examining efficacy differences between compounds. Using rat cerebellar membrane preparations, the effects of GDP concentration on GTP gamma S binding and the activities of a range of cannabinoid receptor ligands, including the CB1 selective antagonist SR141716A, were investigated. GDP concentration was found to have differing effects on cannabinoid-stimulated [35S]GTP gamma S binding depending on the nature of the agonist used. The stimulation produced by high efficacy compounds, such as CP 55,940 and WIN 55212-2, was increased by raising the GDP concentration, but that of a low efficacy agonist, (-)-delta-tetrahydrocannabinol, was decreased. Of the cannabinoid compounds tested, a wide range of potencies (EC50) and levels of maximal stimulation (Emax) were observed. These ranged from CP 55,244 (Emax of 165, 148-183%, and an EC50 of 0.47, 0.22-0.96, nM) through (-)-delta-tetrahydrocannabinol, cannabinol and anandamide, which produced no concentration-dependent stimulation of [35S]GTP gamma S binding under the same conditions. SR141716A competitively antagonized all the agonists against which it was tested, providing equilibrium dissociation constants (Kd values) in the sub-nanomolar range (0.06-0.40 nM), implicating a CB1 receptor mediated response. These results provide a more detailed characterization of the cannabinoid-stimulated [35S]GTP gamma S binding assay than has previously been reported.
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PMID:Evaluation of cannabinoid receptor agonists and antagonists using the guanosine-5'-O-(3-[35S]thio)-triphosphate binding assay in rat cerebellar membranes. 958 May 97

The cannabinoid receptors, CB1 and CB2, are members of the G-protein coupled receptor family and share many of this family's structural features. A highly conserved aspartic acid residue in the second transmembrane domain of G-protein coupled receptors has been shown for many of these receptors to be functionally important for agonist binding and/or G-protein coupling. To determine whether this residue is involved in cannabinoid receptor function, we used site-directed mutagenesis of receptor cDNA followed by expression of the mutant receptor in HEK 293 cells. Aspartate 163 (in CB1) and aspartate 80 (in CB2) were substituted with either asparagine or glutamate. Stably transfected cell lines were tested for radioligand binding and inhibition of cAMP accumulation. Binding of the cannabinoid receptor agonist [3H]CP-55,940 was not affected by either mutation in either the CB1 or CB2 receptor, nor were the affinities of anandamide or (-)-delta 9-tetrahydrocannabinol. Binding of the CB1-selective receptor antagonist SR141716A also was unaltered. However, the affinity of WIN 55,212-2 was attenuated significantly in the CB1, but not the CB2, mutant receptors. Studies examining inhibition of cAMP accumulation showed reduced effects of cannabinoid agonists in the mutated receptors. Our data suggest that this aspartate residue is not generally important for ligand recognition in the cannabinoid receptors; however, it is required for communication with G proteins and signal transduction.
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PMID:Mutation of a highly conserved aspartate residue in the second transmembrane domain of the cannabinoid receptors, CB1 and CB2, disrupts G-protein coupling. 958 Jun 9


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