Late-stage results from the probe development effort to identify antagonists of OPRK1: LCMS-based biochemical cytochrome P450 inhibition assay
Name: Late-stage results from the probe development effort to identify antagonists of OPRK1: LCMS-based biochemical cytochrome P450 inhibition assay. ..more
Source (MLPCN Center Name): The Scripps Research Institute Molecular Screening Center (SRIMSC)
Affiliation: The Scripps Research Institute, TSRI
Assay Provider: Lakshmi A. Devi, Mount Sinai School of Medicine
Network: Molecular Library Probe Production Centers Network (MLPCN)
Grant Proposal Number: R03NS053751
Grant Proposal PI: Lakshmi A. Devi, Mount Sinai School of Medicine
External Assay ID: CYTP450_INH_LCMS_OPRK1_PK
Name: Late-stage results from the probe development effort to identify antagonists of OPRK1: LCMS-based biochemical cytochrome P450 inhibition assay.
Potent and selective OPRK antagonists will be useful for studying the mechanisms involved in OPRK-mediated analgesia and may have therapeutic value as novel analgesics with an improved side effect profile to currently available drugs. Studies have identified a role for dynorphin and OPRK stimulation in neuropathic pain (1). The dynorphins act as endogenous agonists at the opioid receptors, including OPRK (2), and the increased dynorphin expression in neuropathic pain also leads to a sustained activation of OPRK (1, 3). The mechanisms and neural circuits in OPRK-mediated analgesia are active areas of study; it is hoped those studies will assist in the development of novel analgesics that bypass OPRK-mediated depression (4-5). A role for dynorphin/OPRK in modulating drug addiction has been proposed (for review, see (6-7)). The function of dynorphin/OPRK systems in addiction appears to be diverse, and may modulate drug-seeking behavior depending on factors such as drug history, pattern of intake, and stress (for review, see (6)). The availability of potent and selective OPRK ligands may help unravel these mechanisms, as well as prove to be of therapeutic utility. Evidence from preclinical studies indicates that the dynorphin/OPRK system may be dysregulated in affective psychiatric disorders (for review, see (6, 8)). However, solid evidence from clinical studies is lacking. There is increasing evidence for a potential involvement of dynorphin/OPRK in schizophrenia; OPRK agonists appear to induce symptoms in humans and animals that are present in schizophrenia (8-10). Thus, the availability of new research tools such as potent and selective OPRK antagonists will facilitate understanding the physiological and pathophysiological mechanisms of dynorphin/OPRK systems and their roles in psychiatric disease in humans.
1. Xu, M., et al., Neuropathic pain activates the endogenous kappa opioid system in mouse spinal cord and induces opioid receptor tolerance. J Neurosci, 2004. 24(19): p. 4576-84.
2. Chavkin, C., I.F. James, and A. Goldstein, Dynorphin is a specific endogenous ligand of the kappa opioid receptor. Science, 1982. 215(4531): p. 413-5.
3. Xu, M., et al., Sciatic nerve ligation-induced proliferation of spinal cord astrocytes is mediated by kappa opioid activation of p38 mitogen-activated protein kinase. J Neurosci, 2007. 27(10): p. 2570-81.
4. Al-Hasani, R. and M.R. Bruchas, Molecular mechanisms of opioid receptor-dependent signaling and behavior. Anesthesiology, 2011. 115(6): p. 1363-81.
5. Muschamp, J.W., A. Van't Veer, and W.A. Carlezon, Jr., Tracking down the molecular substrates of stress: new roles for p38alpha MAPK and kappa-opioid receptors. Neuron, 2011. 71(3): p. 383-5.
6. Tejeda, H.A., T.S. Shippenberg, and R. Henriksson, The dynorphin/kappa-opioid receptor system and its role in psychiatric disorders. Cell Mol Life Sci, 2012. 69(6): p. 857-96.
7. Yoo, J.H., I. Kitchen, and A. Bailey, The endogenous opioid system in cocaine addiction: what lessons have opioid peptide and receptor knockout mice taught us? Br J Pharmacol, 2012. 166(7): p. 1993-2014.
8. Schwarzer, C., 30 years of dynorphins--new insights on their functions in neuropsychiatric diseases. Pharmacol Ther, 2009. 123(3): p. 353-70.
9. Bortolato, M. and M.V. Solbrig, The price of seizure control: dynorphins in interictal and postictal psychosis. Psychiatry Res, 2007. 151(1-2): p. 139-43.
10. Sheffler, D.J. and B.L. Roth, Salvinorin A: the "magic mint" hallucinogen finds a molecular target in the kappa opioid receptor. Trends Pharmacol Sci, 2003. 24(3): p. 107-9.
OPRK1, kappa, opioid, receptor, mouse, pharmacokinetics, PK assay, human cytochrome P450, CYP1A2, CYP2C9, CYP2D6, CYP3A4, LCMS, LC-MS/MS, antagonist, inhibitor, inhibit, pain, analgesic, neuropathic pain, drug addiction, addiction, Scripps, Scripps DMPK Laboratory, The Scripps Research Institute Molecular Screening Center, SRIMSC, Molecular Libraries Probe Production Centers Network, MLPCN.
§ Panel component ID.
The purpose of this assay is to obtain information regarding potential drug-drug interactions for a lead OPRK antagonist test compound. Inhibition of the four major human isoforms of cytochrome P450 are evaluated by following the metabolism of specific marker substrates CYP1A2, CYP2C9, CYP2D6, and CYP3A4 in the presence test compound.
The metabolism of CYP1A2 (phenaceten demethylated to acetaminophen), CYP2C9 (tolbutamide hydroxylated to hydroxytolbutamide), CYP2D6 (bufuralol hydroxylated to 4'-hydroxybufuralol), and CYP3A4 (midazolam hydroxylated to 1'-hydroxymidazolam) in the presence or absence of 10 uM test compound are evaluated. The concentration of each marker substrate is approximately its Km. Specific inhibitors for each isoform are used to validate the system. Compound concentrations are determined by LC-MS/MS.
PubChem Activity Outcome and Score:
The following applies to each panel in this assay:
Compounds that exhibit less than or equal to 50% inhibition are considered active. Compounds that exhibit greater than 50% inhibition are considered inactive.
List of Reagents:
Reagents were provided by the DMPK Laboratory at The Scripps Research Institute in Florida.
This assay was performed by the DMPK Laboratory at The Scripps Research Institute in Florida with powder samples of synthesized compound.
Categorized Comment - additional comments and annotations
** Test Concentration. § Panel component ID.