Org 27569

Org 27569 is a potent CB1 receptor allosteric modulator, which increases agonist binding, yet blocks agonist-induced CB1 signaling.

Signaling Pathways >> GPCR/G Protein >> Cannabinoid Receptor

Research Areas >> Neurological Disease

Org 27569 enhances agonist (CP55940) binding, promotes agonist binding to CB1 yet inhibits agonist-induced G protein activation and blocks the agonist-induced conformational changes in TM6. Org 27569 inhibits agonist-induced TM6 movement in CB1 detected by a fluorescent probe on site 342[2]. Org 27569 produces a significant, but saturable, increase in the level of specific [3H]CP 55,940 binding. Org 27569 (1 μM) inhibits electrically evoked contractions of the mouse vas deferens with the pEC50 and Emax being 8.66±0.11 and 77% (95% confidence limits, 70.6-82.7), respectively[4]. In hCB1R cells, Org 27569 (1 and 10 μM) behaves as a weak inverse agonist producing a small but significant decrease in basal [35S]GTPγS binding. Org 27569 is less effective as an inhibitor of WIN55212-mediated inhibition of forskolin-stimulated cAMP production. Org 27569 induces a small but significant level of ERK1/2 phosphorylation with an Emax of 19% and pEC50 value of 8.55±0.99[5].

ORG 27569 (3.2 and 5.6 mg/kg, i.p.) significantly attenuates cocaine associated cue-induced reinstatement, cocaine priming-induced reinstatement, methamphetamine associated cue-induced reinstatement and methamphetamine priming-induced reinstatement in rat[1]. Org27569 (30 mg/kg, i.p.) produces CB1-independent hypophagic effects and does not affect the discriminative stimulus effects of anandamide (AEA). Org27569 (100 μg intracerebroventricularly) does not affect the pharmacologic effects of systemically administered CP55,940 compared with vehicle[3].

Binding assays are performed with the CB1 receptor agonist [3H]CP 55,940 (0.7 nM) and the CB1 receptor antagonist [3H]SR 141716A (1.2 nM), 1 mg/mL BSA and 50 mM Tris buffer containing 0.1 mM EDTA and 0.5 mM MgCl2, pH 7.4, in a total assay volume of 500 μL. Binding is initiated by the addition of mouse brain membranes (30 μg). Assays are carried out at 37°C for 60 min before termination by addition of ice-cold wash buffer (50 mM Tris buffer and 1 mg/mL BSA) and vacuum filtration using a 24-well sampling manifold and Whatman GF/B glass-fiber filters that have been soaked in wash buffer at 4°C for 24 h. Each reaction tube is washed five times with a 4-mL aliquot of buffer. The filters are oven-dried for 60 min and then placed in 5 mL of scintillation fluid, and radioactivity is quantitated by liquid scintillation spectrometry. Specific binding is defined as the difference between the binding that occurs in the presence and absence of 1 μM concentrations of the corresponding unlabeled ligand and is 70 to 80% of the total binding.

Following a 1-week acclimation period, CB1 (+/+) and (−/−) mice are food-deprived, given an intraperitoneal injection of Org27569 (30 mg/kg), rimonabant (10 mg/kg; positive control), or vehicle at 23 h, and placed in a plastic cage with access to water. A premeasured amount (2.3-2.6 g) of sweet cereal or standard chow is placed in the test cage from 24 to 26h. All mice receive each treatment condition in a counterbalanced design, with at least 96 h between test days.

[1]. Jing L, et al. Effects of the cannabinoid CB₁ receptor allosteric modulator ORG 27569 on reinstatement of cocaine- and methamphetamine-seeking behavior in rats. Drug Alcohol Depend. 2014 Oct 1;143:251-6.

[2]. Fay JF, et al. A key agonist-induced conformational change in the cannabinoid receptor CB1 is blocked by the allosteric ligand Org 27569. J Biol Chem. 2012 Jul 30.

[3]. Gamage TF, et al. In-vivo pharmacological evaluation of the CB1-receptor allosteric modulator Org-27569. Behav Pharmacol. 2014 Apr;25(2):182-5.

[4]. Price MR, et al. Allosteric modulation of the cannabinoid CB1 receptor. Mol Pharmacol. 2005 Nov;68(5):1484-95.

[5]. Baillie GL, et al. CB(1) receptor allosteric modulators display both agonist and signaling pathway specificity. Mol Pharmacol. 2013 Feb;83(2):322-38.

WIN 55212-2 mesylate | AM251 | Taranabant | SR144528 | Bay 59-3074 | Otenabant | GW842166X | A-836339 | BML-190 | JD-5037 | (±)-SLV319 | Pregnenolone | Anandamide | 2-arachidonoylglycerol | AM1241