N-Substituted <i>cis-</i>4a-(3-Hydroxyphenyl)-8a-methyloctahydroisoquinolines Are Opioid Receptor Pure Antagonists

Carroll, F. Ivy; Chaudhari, Sachin S.; Thomas, James B.; Mascarella, S. Wayne; Gigstad, Kenneth M.; Deschamps, Jeffrey R.; Navarro, Hernán A.

doi:10.1021/jm058261c

Cited by 17 publications

(19 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The assays were conducted in a 96-well plate format as previously described (Carroll et al 2005; Thomas et al 2005). For measurement of [ 35 S]GTPγ binding activation, membranes were resuspended in 50 mM Tris–HCl, 3 mM MgCl 2 , 0.2 mM EGTA, and 100 mM NaCl, pH 7.4.…”

Section: Methodsmentioning

confidence: 99%

Kappa opioid mediation of cannabinoid effects of the potent hallucinogen, salvinorin A, in rodents

et al. 2010

Self Cite

View full text Add to dashboard Cite

Rationale Salvinorin A, the primary psychoactive derivative of the hallucinogenic herb Salvia divinorum, is a potent and highly selective kappa-opioid receptor (KOR) agonist. Several recent studies, however, have suggested endocannabinoid system mediation of some of its effects. Objectives This study represents a systematic examination of this hypothesis. Methods Salvinorin A was isolated from S. divinorum and was evaluated in a battery of in vitro and in vivo procedures designed to detect cannabinoid activity, including CB1 receptor radioligand and [35S]GTPγS binding, calcium flux assay, in vivo cannabinoid screening tests, and drug discrimination. Results Salvinorin A did not bind to nor activate CB1 receptors. In vivo salvinorin A produced pronounced hypolocomotion and antinociception (and to a lesser extent, hypothermia). These effects were blocked by the selective KOR antagonist, JDTic, but not by the CB1 receptor antagonist rimonabant. Interestingly, however, rimonabant attenuated KOR activation stimulated by U69,593 in a [35S]GTPγS assay. Salvinorin A did not substitute for Δ9-tetrahydrocannabinol (THC) in mice trained to discriminate THC. Conclusions These findings suggest that similarities in the pharmacological effects of salvinorin A and those of cannabinoids are mediated by its activation of KOR rather than by any direct action of salvinorin A on the endocannabinoid system. Further, the results suggest that rimonabant reversal of salvinorin A effects in previous studies may be explained in part by rimonabant attenuation of KOR activation.

show abstract

Section: Methodsmentioning

confidence: 99%

Kappa opioid mediation of cannabinoid effects of the potent hallucinogen, salvinorin A, in rodents

et al. 2010

Self Cite

View full text Add to dashboard Cite

show abstract

“…Cells were cultured as described above for 24 to 48 h, washed once with sterile PBS, and then serum-starved overnight. DAMGO-stimulated [ 35 S]GTP␥S binding and Western blotting were assayed in HEK293 membrane homogenates as described previously (Carroll et al, 2005). In brief, cells were treated with vehicle, DAMGO (1 M), EGF (50 ng/ml), or DAMGO ϩ EGF at specified time points.…”

Section: Hek293 Cellmentioning

confidence: 99%

Phosphorylation of the μ-Opioid Receptor at Tyrosine 166 (Tyr3.51) in the DRY Motif Reduces Agonist Efficacy

et al. 2009

View full text Add to dashboard Cite

The effects of phosphorylation of the tyrosine residue in the highly conserved DRY motif expressed in the putative second cytoplasmic loop of the -opioid receptor were assessed after expression in human embryonic kidney (HEK) 293 cells. Tyrosine kinase activation by epidermal growth factor (EGF) or hydrogen peroxide treatment effectively increased phosphorylation of the tyrosine-166 in the -opioid receptor (MORTyr166p) as measured by a novel phosphoselective antibody. We were surprised to find that the increase in MOR-Tyr166p immunoreactivity (ir) required coactivation by the opioid agonist [D-Ala 2 ,methyl-Phe 4 ,Gly 5 -ol]enkephalin (DAMGO), as demonstrated by both Western blot imaging of membrane proteins and confocal microscopy of transfected cells; MOR-Tyr166p-ir did not significantly increase after either DAMGO, EGF, or H 2 O 2 treatment alone. The increase in MOR-Tyr166p-ir was blocked by pretreatment with the opioid antagonist naloxone or the Src kinase inhibitor 4-amino-5-(4-chloro-phenyl)-7-(t-butyl)pyrazolo [3,4-d]pyrimidine. Consistent with these data, mutation of the tyrosine-166 to phenylalanine blocked the increased immunoreactivity, and untransfected HEK293 cells did not increase MOR-Tyr166p-ir after treatment. DAMGO The -opioid receptor (MOR; OPRM1) belongs to the class A (rhodopsin family) G i/o -coupled family of G-protein-coupled receptors (GPCRs) and functions to reduce neuronal excitability primarily by increasing potassium conductance and inhibiting voltage-gated calcium channels (Law et al., 2000;Williams et al., 2001). The opioid system is usually described within the context of drug abuse and analgesic drug action; however, the normal physiological role of the opioid system is to regulate pain sensitivity, endocrine functioning, gut motility, and smooth muscle tone in response to physiological stressors (López et al., 1999;Drolet et al., 2001). The regulation of -opioid signaling is a dynamic and complex process (Law et al., 2000). A primary desensitization mechanism involving G-protein receptor kinase (GRK) and ␤-arrestindependent internalization through cytoplasmic serine/threonine phosphorylation has been well described previously (Celver et al., 2001(Celver et al., , 2004Williams et al., 2001). In addition, MOR contains four highly conserved cytoplasmic tyrosine residues (Thompson et al., 1993), and tyrosine kinase-mediated mechanisms regulating MOR signaling have also been described previously (McLaughlin and Chavkin, 2001;Zhang et al., 2009). Tyrosine phosphorylation may influence MOR trafficking and signaling (Pak et al., 1999), consistent with the effects of tyrosine phosphorylation on internalization and signaling of the ␦-and -opioid receptors (Kramer et al., 2000;Appleyard et al., 2000). A recent study by Law and colleagues showed that tyrosine phosphorylation of MOR at Tyr166 and Tyr336 controlled the switch from inhibition to

show abstract

“…These data were obtained by monitoring the ability of test compounds to inhibit stimulated [ 35 S ]GTP γ S binding produced by the selective agonists DAMGO ( μ ), DPDPE ( δ ), or U69,593 ( κ ) using cloned human opioid receptors expressed in CHO cells. 29 Agonist dose response curves were run in the presence or absence of a single concentration of test compound. Test compound assay concentrations ranged from 1–5000 nM, depending on their activity.…”

Section: Pharmacologymentioning

confidence: 99%

Synthesis and In Vitro Opioid Receptor Functional Antagonism of Methyl-Substituted Analogues of (3R)-7-Hydroxy-N-[(1S)-1-{[(3R,4R)-4-(3-hydroxyphenyl)-3,4-dimethyl-1-piperidinyl]methyl}-2-methylpropyl]-1,2,3,4-tetrahydro-3-isoquinolinecarboxamide (JDTic)

et al. 2009

Self Cite

View full text Add to dashboard Cite

In previous structure–activity relationship (SAR) studies, (3R)-7-hydroxy-N-[(1S)-1-{[(3R,4R)-4-(3-hydroxyphenyl)-3,4-dimethyl-1-piperidinyl]methyl}-2-methylpropyl]-1,2,3,4-tetrahydro-3-isoquinolinecarboxamide (JDTic, 3) was identified as the first potent and selective κ-opioid receptor antagonist from the trans-3,4-dimethyl-4-(3-hydroxyphenyl)piperidine class of opioid antagonists. In the present study, we report the synthesis of analogues 8a–p of 3 and present their in vitro opioid receptor functional antagonism using a [35S]GTPγS binding assay. Compounds 8a–p are analogues of 3 containing one, two, or three methyl groups connected to the JDTic structure at five different positions. All the analogues with one and two added methyl groups with the exception of 8k had subnanomolar Ke values at the κ receptor. The three most potent analogues were the monomethylated (3R)-7-hydroxy-N-[(1S,2S)-1-{[(3R,4R)-4-(3-hydroxyphenyl)-3,4-dimethylpiperidine-1-yl]methyl}-2-methylbutyl]-1,2,3,4-tetrahydroisoquinoline-3-carboxamide (8a) and (3R)-7-hydroxy-N-[(1S)-1-{[(3R,4R)-4-(3-hydroxyphenyl)-3,4-dimethylpiperidin-1-yl]methyl}-(2-methylpropyl)]-3-methyl-1,2,3, 4-tetrahydroisoquinoline-3-carboxamide (8e) with Ke values of 0.03 nM at the κ receptor and (3R)-7-hydroxy-N-[(1S)-1-{[(3R,4R)-4-(3-methoxyphenyl)-3,4-dimethylpiperidin-1-yl]methyl}-2-methylpropyl]-1,2,3,4-tetrahydroisoquinoline-3-carboxamide (8d) with Ke=0.037 nM at the κ receptor. All three compounds were selective for the κ receptor relative to the μ and δ receptors. Overall, the results from this study highlight those areas that are tolerant to substitution on 3.

show abstract

N-Substituted cis-4a-(3-Hydroxyphenyl)-8a-methyloctahydroisoquinolines Are Opioid Receptor Pure Antagonists

Cited by 17 publications

References 28 publications

Kappa opioid mediation of cannabinoid effects of the potent hallucinogen, salvinorin A, in rodents

Kappa opioid mediation of cannabinoid effects of the potent hallucinogen, salvinorin A, in rodents

Phosphorylation of the μ-Opioid Receptor at Tyrosine 166 (Tyr3.51) in the DRY Motif Reduces Agonist Efficacy

Synthesis and In Vitro Opioid Receptor Functional Antagonism of Methyl-Substituted Analogues of (3R)-7-Hydroxy-N-[(1S)-1-{[(3R,4R)-4-(3-hydroxyphenyl)-3,4-dimethyl-1-piperidinyl]methyl}-2-methylpropyl]-1,2,3,4-tetrahydro-3-isoquinolinecarboxamide (JDTic)

Contact Info

Product

Resources

About