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

In order to gain information about the topology of the brain cannabinoid receptor (CB1), a Receptor Steric (RS) Map for cannabinoids at this receptor was calculated. The classical cannabinoids (-)-11-hydroxy-delta-9-tetrahydrocannabinol (K1 = 210 +/- 56 nM), (-)-9-nor-9-beta-hydroxy-hexahydrocannabinol (K1 = 124 +/- 17 nM), nabilone (K1 = 120 +/- 13 nM), and the non-classical cannabinoid, CP-55,244 (K1 = 1.4 +/- .3 nM) were used as template molecules. The RS map was obtained as the union of the van der Waals' volumes of only those accessible conformers identified by MMP2 calculations that were able to clear a region of steric interference at the CB1 receptor previously characterized by us [Reggio, P.H., Panu, A.M. and Miles, S. (1993), J. Med. Chem., 36, 1761-1771]. The utility of the RS Map was explored by screening the accessible conformers of the classical cannabinoid, cannabinol (CBN), (K1 = 3200 +/- 450 nM), for its ability to fit within the RS map. Only the global minimum energy conformer of CBN (53.2% abundance at 298K) was able to fit within the RS map. These results imply that one reason for the reduced affinity of CBN may be that only 53.2% of CBN molecules are shaped properly to fit in the binding pocket for cannabinoids at the CB1 receptor.
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PMID:Construction of a steric map of the binding pocket for cannabinoids at the cannabinoid receptor. 766 29

Anandamide (AN) is an arachidonic acid congener, found in the brain, that binds to the cannabinoid receptor and elicits cannabinoid-like pharmacological activity. Cytochromes P450 (P450s) are known to oxidize arachidonic acid to a wide variety of metabolites, yielding many physiologically potent compounds. To determine if AN could be similarly oxidized by P450s, its metabolism by mouse liver and brain microsomes was examined. Mouse hepatic microsomal incubation of AN with NADPH resulted in the generation of at least 20 metabolites, determined after HPLC separation by increased UV-absorbance at 205 nm. Pretreatment of mice with various P450 inducers resulted in increased hepatic microsomal formation of several AN metabolites, with dexamethasone being the most effective inducer. Phenobarbital pretreatment resulted in a metabolic profile similar to that observed after dexamethasone pretreatment, whereas 3-methylcholanthrene pretreatment selectively increased the formation of several other metabolites. Clofibrate pretreatment had no effect on hepatic AN metabolism. Polyclonal antibodies prepared against mouse hepatic P450 3A inhibited the formation of several AN metabolites by hepatic microsomes from untreated mice as well as the formation of those metabolites found to be increased after dexamethasone pretreatment. AN metabolism by brain microsomes resulted in the formation of two NADPH- and protein-dependent metabolites. Hepatic P450 3A antibody partially inhibited the formation of only one of these metabolites. Thus, P450 3A is a major contributor to AN metabolism in the liver but not in the brain. The physiological consequences of P450-mediated AN metabolism remain to be determined.
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PMID:Microsomal cytochrome P450-mediated liver and brain anandamide metabolism. 766 71

A brain constituent, the N-amide derivative of arachidonic acid, termed anandamide, has been recently proposed as a possible endogenous ligand for the cannabinoid receptor. The present study has been designed to examine whether the acute or chronic exposure to anandamide affected the binding of cannabinoid receptors in specific brain areas as occurred with the exogenous cannabinoid agonist, delta 9-tetrahydrocannabinol (THC). To this end, we measured the maximum binding capacity (Bmax) and the affinity (Kd) of cannabinoid receptors, by using [3H]CP-55,940 binding assays, in membranes obtained from several brain areas of male rats acutely or chronically treated with anandamide or THC. Results were as follows. The acute administration of either anandamide or THC increased the Bmax of cannabinoid receptors in the cerebellum and, particularly, in the hippocampus. This effect was also observed after 5 days of a daily exposure to either anandamide or THC. However, whereas the increase in the Bmax after the acute treatment seems to be caused by changes in the receptor affinity (high Kd), the increase after the chronic exposure may be attributed to an increase in the density of receptors. On the contrary, the [3H]CP-55,940 binding to cannabinoid receptors in the striatum, the limbic forebrain, the mesencephalon, and the medial basal hypothalamus was not altered after the acute exposure to anandamide or THC. However, the chronic exposure to THC significantly decreased the Bmax of these receptors in the striatum and nonsignificantly in the mesencephalon. This effect was not elicited after the chronic exposure to anandamide and was not accompanied by changes in the Kd.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Changes in rat brain cannabinoid binding sites after acute or chronic exposure to their endogenous agonist, anandamide, or to delta 9-tetrahydrocannabinol. 767 52

Using in situ hybridization we found that chronic treatment with CP-55,940 (0.4 mg kg-1, i.p. daily for 11 days), a synthetic cannabinoid receptor ligand, changed cannabinoid receptor mRNA levels in rat brain. CP-55,940 produced the expected tolerance: the decrease in locomotor activity (75%) caused by an acute dose was diminished to 25% after the 11 days of treatment. Thirty minutes after the last injection the animals were killed and in situ hybridization indicated that the levels of cannabinoid receptor mRNA in the caudate-putamen were reduced by 33%, with no alteration in the other brain areas. We suggest that the altered cannabinoid receptor expression is part of the adaptive changes underlying cannabinoid tolerance.
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PMID:Chronic CP-55,940 alters cannabinoid receptor mRNA in the rat brain: an in situ hybridization study. 769 88

The effects of the novel high affinity cannabinoid receptor agonist (+)-WIN 55,212-2 ((R)-4,5-dihydro-2-methyl-4(4-morphoinylmethyl)-1-(1-naphthalen ylcarbonyl)-6H-pyrrolo[3,2,1-ij]quinolin-6-one) on severity of dystonia were investigated in mutant Syrian hamsters with primary generalized dystonia. Following injections of (+)-WIN 55,212-2 (1.0-5.0 mg/kg i.p.) a dose-dependent reduction of the severity of dystonia was observed. At antidystonic doses (2.5 and 5.0 mg/kg i.p.) (+)-WIN 55,212-2 caused a reduction of spontaneous motor activity and catalepsy. 1 mg/kg of (+)-WIN 55,212-2 exhibited neither antidystonic effects nor any side effects. However, the coadministration of 1.0 mg/kg (+)-WIN 55,212-2 with an ineffective dose of diazepam (0.1 mg/kg i.p.) exerted antidystonic effects in the absence of severe side effects. Although psychotropic effects of cannabinoids, such as (+)-WIN 55,212-2, limit the therapeutical utility of cannabinoids, the present data indicate that cannabinoids exert antidystonic effects and that low doses of cannabinoids may increase antidystonic efficacy of benzodiazepines.
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PMID:(+)-WIN 55,212-2, a novel cannabinoid receptor agonist, exerts antidystonic effects in mutant dystonic hamsters. 769 78

It is recognized that a number of the biological effects of delta 9-tetrahydrocannabinol (THC) can be attributed to a cannabinoid receptor found in abundance in the brain. Due to observations that cannabinoid drugs exert some developmental toxicity, it was of interest to examine the developmental pattern of cannabinoid receptors in the brain of neonatal rats through young adulthood, and then to further examine the cannabinoid receptor during the aging process in the brain of rats 3 to 32 months of age. Using radioligand binding assays, this study demonstrated that cannabinoid receptor binding capacity increases progressively from birth to postnatal day (PND) 60. Within the striatum, a significant increase in binding occurred between PNDs 14 and 21. In the cerebellum, cannabinoid receptor binding capacity doubled at 7-day postnatal intervals until adulthood. Cannabinoid receptor binding in the cortex doubled between PNDs 7 and 14. Within the hippocampus, there were small incremental increases until the final adult level was reached at PND 21. There was no significant alteration in the affinity for CP-55940 during development. These findings might reflect an increased differentiation of neurons into cells possessing cannabinoid receptors, or an increase in the number of cannabinoid receptors on cell bodies or projections in regions undergoing developmental changes. Once the adult cannabinoid receptor levels have been reached, binding activity in the whole brain preparation neither increased nor declined during the normal aging process.
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PMID:The ontogeny of cannabinoid receptors in the brain of postnatal and aging rats. 770 16

The endogenous cannabinoid receptor ligand, anandamide, produced a concentration related inhibition of electrically evoked contractions of the guinea-pig myenteric plexus preparation. Its potency was markedly enhanced by phenylmethylsulphonyl fluoride (2.0-200 microM) which presumably acts by inhibiting the hydrolysis of anandamide in this preparation. The degree of this potentiation increased with the concentration of phenylmethylsulphonyl fluoride used. The methyl analogue of anandamide, R-(+)-arachidonyl-1'-hydroxy-2'-propylamide, also inhibited contractions of the guinea-pig myenteric plexus preparation. The potency of this compound was much less affected by phenylmethylsulphonyl fluoride than was the potency of anandamide, confirming its greater resistance to hydrolysis. Phenylmethylsulphonyl fluoride did not alter the inhibitory potency of the cannabinoid, CP 55,940 ((-)-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-4- [3-hydroxypropyl]cyclohexan-1-ol), which is not an amidase substrate. Nor did phenylmethylsulphonyl fluoride affect the ability of anandamide to inhibit electrically evoked contractions of the mouse vas deferens, suggesting that anandamide does not undergo hydrolysis in this tissue.
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PMID:Effect of phenylmethylsulphonyl fluoride on the potency of anandamide as an inhibitor of electrically evoked contractions in two isolated tissue preparations. 771 52

Mast cells are multifunctional bone marrow-derived cells found in mucosal and connective tissues and in the nervous system, where they play important roles in tissue inflammation and in neuroimmune interactions. Very little is known about endogenous molecules and mechanisms capable of modulating mast cell activation. Palmitoylethanolamide, found in peripheral tissues, has been proposed to behave as a local autacoid capable of downregulating mast cell activation and inflammation. A cognate N-acylamide, anandamide, the ethanolamide of arachidonic acid, occurs in brain and is a candidate endogenous agonist for the central cannabinoid receptor (CB1). As a second cannabinoid receptor (CB2) has been found in peripheral tissues, the possible presence of CB2 receptors on mast cells and their interaction with N-acylamides was investigated. Here we report that mast cells express both the gene and a functional CB2 receptor protein with negative regulatory effects on mast cell activation. Although both palmitoylethanolamide and anandamide bind to the CB2 receptor, only the former downmodulates mast cell activation in vitro. Further, the functional effect of palmitoylethanolamide, as well as that of the active cannabinoids, was efficiently antagonized by anandamide. The results suggest that (i) peripheral cannabinoid CB2 receptors control, upon agonist binding, mast cell activation and therefore inflammation; (ii) palmitoylethanolamide, unlike anandamide, behaves as an endogenous agonist for the CB2 receptor on mast cells; (iii) modulatory activities on mast cells exerted by the naturally occurring molecule strengthen a proposed autacoid local inflammation antagonism (ALIA) mechanism; and (iv) palmitoylethanolamide and its derivatives may provide antiinflammatory therapeutic strategies specifically targeted to mast cells ("ALIAmides").
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PMID:Mast cells express a peripheral cannabinoid receptor with differential sensitivity to anandamide and palmitoylethanolamide. 772 69

The endogeneous ligand for the cannabinoid receptor, arachidonylethanolamide (anandamide) and its analogues, oleinylethanolamide, palmitylethanolamide and eicosapentaenoylethanolamide, were derivatized with a fluorogenic reagent, 4-(N-chloroformylmethyl-N-methyl)amino-7-N,N-dimethylaminsulpho ny1-2,1,3- benzoxadiazole (DBD-COCl). They were separated on a reversed phase HPLC with a mobile phase of acetonitrile:water. The fluorometric detection of the derivatives was made at 560 nm with excitation at 450 nm and the detection limits for anandamide was 20 fmol on column. The structures of DBD-CO-ethanolamides were confirmed by liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS).
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PMID:High-performance liquid chromatography and fluorometric detection of arachidonylethanolamide (anandamide) and its analogues, derivatized with 4-(N-chloroformylmethyl-N-methyl)amino-7-N,N-dimethylaminosulp honyl-2,1 ,3- benzoxadiazole (DBD-COCl). 773 36

Using RNA (Northern) blot hybridization and reverse transcription-PCR, we demonstrate that the brain-type cannabinoid receptor (CB1-R) mRNA, but not the spleen-type cannabinoid receptor (CB2-R) mRNA, is expressed in the mouse uterus and that this organ has the capacity to synthesize the putative endogenous cannabinoid ligand, anandamide (arachidonylethanolamide). The psychoactive cannabinoid component of marijuana--delta 9-tetrahydrocannabinol (THC)--or anandamide, but not the inactive and nonpsychoactive cannabidiol (CBD), inhibited forskolin-stimulated cyclic AMP formation in the mouse uterus, which was prevented by pertussis toxin pretreatment. These results suggest that uterine CB1-R is coupled to inhibitory guanine nucleotide-binding protein and is biologically active. Autoradiographic studies identified ligand binding sites ([3H]anandamide) in the uterine epithelium and stromal cells, suggesting that these cells are perhaps the targets for cannabinoid action. Scatchard analysis of the binding of [3H]WIN 55212-2, another cannabinoid receptor ligand, showed a single class of high-affinity binding sites in the endometrium with an apparent Kd of 2.4 nM and Bmax of 5.4 x 10(9) molecules per mg of protein. The gene encoding lactoferrin is an estrogen-responsive gene in the mouse uterus that was rapidly and transiently up-regulated by THC, but not by CBD, in ovariectomized mice in the absence of ovarian steroids. This effect, unlike that of 17 beta-estradiol (E2), was not influenced by a pure antiestrogen, ICI 182780, suggesting that the THC-induced uterine lactoferrin gene expression does not involve estrogen receptors. We propose that the uterus is a new target for cannabinoid ligand-receptor signaling.
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PMID:Cannabinoid ligand-receptor signaling in the mouse uterus. 775 7


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