am-356 and 4-(3-3-4-p-menthadien-(1-8)-yl)olivetol

We have previously shown that the endocannabinoid anandamide and its metabolically stable analog (R)-methanandamide produce vasorelaxation in rabbit aortic ring preparations in an endothelium-dependent manner that could not be mimicked by other CB(1) cannabinoid receptor agonists (Am J Physiol 282: H2046-H2054, 2002). Here, we show that (R)-methanandamide and abnormal cannabidiol stimulated nitric oxide (NO) production in rabbit aortic endothelial cells (RAEC) in a dose-dependent manner but that other CB(1) and CB(2) receptor agonists, such as cis-3R-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-trans-4R-3(3-hydroxypropyl)-1R-cyclohexanol (CP55940) and (R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl) pyrrolo-[1,2,3-d,e]-1,4-benzoxazin-6-yl]-1-naphthalenyl-methanone (WIN55212-2), failed to do so. CB(1) antagonists rimonabant [also known as SR141716; N-piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide] and 6-methoxy-2-(4-methoxyphenyl)benzo[b]-thien-3-yl][4-cyanophenyl]methanone (LY320135) and CB(2) antagonist N-[(1S)-endo-1,3,3,-trimethylbicyclo[2.2.1]heptan-2-yl]-5-(4-chloro-3-methylphenyl)-1-(4-methylbenzyl)-pyrazole-3-carboxamide (SR144528) failed to block (R)-methanandamide-mediated NO production in RAEC. However, anandamide receptor antagonist (-)-4-(3-3,4-trans-p-menthadien-(1,8)-yl)-orcinol (O-1918) blocked (R)-methanandamide-mediated NO production in RAEC. Reverse transcriptase-polymerase chain reaction and Western blot analyses failed to detect the CB(1) receptor in RAEC, making this a good model to study non-CB(1) responses to anandamide. (R)-Methanandamide produced endothelial nitric-oxide synthase (eNOS) phosphorylation via the activation of phosphoinositide 3-kinase-Akt signaling. Inhibition of G(i) signaling with pertussis toxin, or phosphatidylinositol 3-kinase activity with 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one (LY294002), resulted in a decrease in (R)-methanandamide-induced Akt phosphorylation and NO production. Results from this study suggest that in RAEC, (R)-methanandamide acts on a novel non-CB(1) and non-CB(2) anandamide receptor and signals through G(i) and phosphatidylinositol 3-kinase, leading to Akt activation, eNOS phosphorylation, and NO production.

Topics: Animals; Arachidonic Acids; Benzofurans; Benzoxazines; Camphanes; Cannabinoid Receptor Modulators; Cells, Cultured; Chromones; Cyclohexanols; Dose-Response Relationship, Drug; Endocannabinoids; Endothelial Cells; Enzyme Inhibitors; GTP-Binding Protein alpha Subunits, Gi-Go; Morpholines; Naphthalenes; Nitric Oxide; Pertussis Toxin; Phosphoinositide-3 Kinase Inhibitors; Phosphorylation; Piperidines; Polyunsaturated Alkamides; Proto-Oncogene Proteins c-akt; Pyrazoles; Rabbits; Receptor, Cannabinoid, CB1; Receptor, Cannabinoid, CB2; Resorcinols; Rimonabant; Signal Transduction

Cannabidiol has been reported to be a neuroprotectant, but the neuroprotective mechanism of cannabidiol remains unclear. We studied the neuroprotective mechanism of cannabidiol in 4-hour middle cerebral artery (MCA) occlusion mice.. Male MCA occluded mice were treated with cannabidiol, abnormal cannabidiol, anandamide, methanandamide, cannabidiol plus capsazepine, and cannabidiol plus WAY100135 before and 3 hours after MCA occlusion. The infarct size was determined after 24 hours (2,3,5-triphenyltetrazolium chloride staining). Cerebral blood flow (CBF) was measured at, before and 1, 2, 3, and 4 hours after MCA occlusion.. Cannabidiol significantly reduced the infarct volume induced by MCA occlusion in a bell-shaped curve. Similarly, abnormal cannabidiol but not anandamide or methanandamide reduced the infarct volume. Moreover, the neuroprotective effect of cannabidiol was inhibited by WAY100135, a serotonin 5-hydroxytriptamine1A (5-HT1A) receptor antagonist but not capsazepine a vanilloid receptor antagonist. Cannabidiol increased CBF to the cortex, and the CBF was partly inhibited by WAY100135 in mice subjected to MCA occlusion.. Cannabidiol and abnormal cannabidiol reduced the infarct volume. Furthermore, the neuroprotective effect of cannabidiol was inhibited by WAY100135 but not capsazepine, and the CBF increased by cannabidiol was partially reversed by WAY100135. These results suggested that the neuroprotective effect of cannabidiol may be related to the increase in CBF through the serotonergic 5-HT1A receptor.

Topics: Animals; Arachidonic Acids; Cannabidiol; Cerebral Infarction; Cerebrovascular Circulation; Endocannabinoids; Infarction, Middle Cerebral Artery; Male; Mice; Neuroprotective Agents; Piperazines; Polyunsaturated Alkamides; Receptor, Serotonin, 5-HT1A; Resorcinols; Serotonin 5-HT1 Receptor Antagonists; Serotonin Antagonists