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Kappa Opioid receptor

Template:DISPLAYTITLE:kappa Opioid receptor

Opioid receptor, kappa 1
Symbol(s) OPRK1; KOR; OPRK
External IDs OMIM: 165196 MGI: 97439 Homologene: 20253
RNA expression pattern

More reference expression data

Human Mouse
Entrez 4986 18387
Ensembl ENSG00000082556 ENSMUSG00000025905
Uniprot P41145 Q14AL5
Refseq NM_000912 (mRNA)
NP_000903 (protein)
NM_011011 (mRNA)
NP_035141 (protein)
Location Chr 8: 54.3 - 54.33 Mb Chr 1: 5.58 - 5.59 Mb
Pubmed search [1] [2]

The κ-Opioid receptors are a class of opioid receptors with dynorphins as the primary endogenous ligands, and ketazocine as a potent selective exogenous ligand. There are three variants: κ1, κ2, and κ3.



It has long been believed that kappa-opioid receptor agonists are dysphoric. This misconception traces back to early articles in the 1980s about human tests with κ-opioid receptor agonists. It was stated that:

"Both doses of ketocyclazocine substantially elevated scores on the LSD subscale of the ARCI as did the high dose of cyclazocine (fig. 2C). Morphine failed to increase scores significantly on this scale which measures dysphoria."[1]

It is now widely accepted that κ-opioid receptor (partial) agonists have hallucinogenic ("psychotomimetic") effects, as exemplified by salvinorin A. These effects are generally undesirable in medicinal drugs and could have had frightening or disturbing effects in the tested humans, but they are not per se dysphoric. It is thought that the hallucinogenic effects of drugs such as butorphanol, nalbuphine, and pentazocine serve to limit their opiate abuse potential. In the case of salvinorin A, a structurally novel neoclerodane diterpene κ-opioid receptor agonist, thes hallucinogenic effects are sought after. While salvinorin A is considered a hallucinogen, its effects are qualitatively different than those produced by the classical psychedelic hallucinogens such as LSD or mescaline.[2]

Activation of the κ-opioid receptor appears to antagonize many of the effects of the μ opioid receptor.[3]

Kappa ligands are also known for their characteristic diuretic effects, due to their negative regulation of antidiuretic hormone (ADH).[4]

Kappa agonism is neuroprotective against hypoxia/ischemia; as such, kappa receptors may represent a novel therapeutic target.[5]


κ receptors are located in the periphery by pain neurons, in the spinal cord and in the brain.


Non-specific opioid receptor antagonists (e.g., naloxone) as well as the mixed opioid agonist/antagonist buprenorphine can be used to reverse the effects of kappa agonists.


  1. ^ Kumor KM, Haertzen CA, Johnson RE, Kocher T, Jasinski D (1986). "Human psychopharmacology of ketocyclazocine as compared with cyclazocine, morphine and placebo". J. Pharmacol. Exp. Ther. 238 (3): 960–8. PMID 3018228.
  2. ^ Roth BL, Baner K, Westkaemper R, Siebert D, Rice KC, Steinberg S, Ernsberger P, Rothman RB (2002). "Salvinorin A: a potent naturally occurring nonnitrogenous kappa opioid selective agonist". Proc. Natl. Acad. Sci. U.S.A. 99 (18): 11934–9. doi:10.1073/pnas.182234399. PMID 12192085.
  3. ^ Pan ZZ (1998). "mu-Opposing actions of the kappa-opioid receptor". Trends Pharmacol. Sci. 19 (3): 94–8. doi:10.1016/S0165-6147(98)01169-9. PMID 9584625.
  4. ^ Yamada K, Imai M, Yoshida S (1989). "Mechanism of diuretic action of U-62,066E, a kappa opioid receptor agonist". Eur. J. Pharmacol. 160 (2): 229–37. PMID 2547626.
  5. ^ Zeynalov E, Nemoto M, Hurn PD, Koehler RC, Bhardwaj A (2006). "Neuroprotective effect of selective kappa opioid receptor agonist is gender specific and linked to reduced neuronal nitric oxide". J. Cereb. Blood Flow Metab. 26 (3): 414–20. doi:10.1038/sj.jcbfm.9600196. PMID 16049424.

Further reading

  • Hatzoglou A, Bakogeorgou E, Kampa M, et al. (2000). "Somatostatin and opioid receptors in mammary tissue. Role in cancer cell growth.". Adv. Exp. Med. Biol. 480: 55-63. PMID 10959409.
  • Narita M, Funada M, Suzuki T (2001). "Regulations of opioid dependence by opioid receptor types.". Pharmacol. Ther. 89 (1): 1-15. PMID 11316510.
  • Simonin F, Gavériaux-Ruff C, Befort K, et al. (1995). "kappa-Opioid receptor in humans: cDNA and genomic cloning, chromosomal assignment, functional expression, pharmacology, and expression pattern in the central nervous system.". Proc. Natl. Acad. Sci. U.S.A. 92 (15): 7006-10. PMID 7624359.
  • Zhu J, Chen C, Xue JC, et al. (1995). "Cloning of a human kappa opioid receptor from the brain.". Life Sci. 56 (9): PL201-7. PMID 7869844.
  • Wang JB, Johnson PS, Wu JM, et al. (1994). "Human kappa opiate receptor second extracellular loop elevates dynorphin's affinity for human mu/kappa chimeras.". J. Biol. Chem. 269 (42): 25966-9. PMID 7929306.
  • Mansson E, Bare L, Yang D (1994). "Isolation of a human kappa opioid receptor cDNA from placenta.". Biochem. Biophys. Res. Commun. 202 (3): 1431-7. PMID 8060324.
  • Yasuda K, Espinosa R, Takeda J, et al. (1994). "Localization of the kappa opioid receptor gene to human chromosome band 8q11.2.". Genomics 19 (3): 596-7. doi:10.1006/geno.1994.1117. PMID 8188308.
  • Chao CC, Gekker G, Hu S, et al. (1996). "kappa opioid receptors in human microglia downregulate human immunodeficiency virus 1 expression.". Proc. Natl. Acad. Sci. U.S.A. 93 (15): 8051-6. PMID 8755601.
  • Lee JW, Joshi S, Chan JS, Wong YH (1998). "Differential coupling of mu-, delta-, and kappa-opioid receptors to G alpha16-mediated stimulation of phospholipase C.". J. Neurochem. 70 (5): 2203-11. PMID 9572309.
  • Chatzaki E, Margioris AN, Makrigiannakis A, et al. (2000). "Kappa opioids and TGFbeta1 interact in human endometrial cells.". Mol. Hum. Reprod. 6 (7): 602-9. PMID 10871647.
  • Gomes I, Jordan BA, Gupta A, et al. (2001). "Heterodimerization of mu and delta opioid receptors: A role in opiate synergy.". J. Neurosci. 20 (22): RC110. PMID 11069979.
  • Mathieu-Kia AM, Fan LQ, Kreek MJ, et al. (2001). "Mu-, delta- and kappa-opioid receptor populations are differentially altered in distinct areas of postmortem brains of Alzheimer's disease patients.". Brain Res. 893 (1-2): 121-34. PMID 11223000.
  • Lokensgard JR, Gekker G, Peterson PK (2002). "Kappa-opioid receptor agonist inhibition of HIV-1 envelope glycoprotein-mediated membrane fusion and CXCR4 expression on CD4(+) lymphocytes.". Biochem. Pharmacol. 63 (6): 1037-41. PMID 11931835.
  • Li JG, Chen C, Liu-Chen LY (2002). "Ezrin-radixin-moesin-binding phosphoprotein-50/Na+/H+ exchanger regulatory factor (EBP50/NHERF) blocks U50,488H-induced down-regulation of the human kappa opioid receptor by enhancing its recycling rate.". J. Biol. Chem. 277 (30): 27545-52. doi:10.1074/jbc.M200058200. PMID 12004055.
  • Suzuki S, Chuang LF, Yau P, et al. (2002). "Interactions of opioid and chemokine receptors: oligomerization of mu, kappa, and delta with CCR5 on immune cells.". Exp. Cell Res. 280 (2): 192-200. PMID 12413885.
  • Strausberg RL, Feingold EA, Grouse LH, et al. (2003). "Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences.". Proc. Natl. Acad. Sci. U.S.A. 99 (26): 16899-903. doi:10.1073/pnas.242603899. PMID 12477932.
  • McLaughlin JP, Xu M, Mackie K, Chavkin C (2003). "Phosphorylation of a carboxyl-terminal serine within the kappa-opioid receptor produces desensitization and internalization.". J. Biol. Chem. 278 (36): 34631-40. doi:10.1074/jbc.M304022200. PMID 12815037.
  • Ota T, Suzuki Y, Nishikawa T, et al. (2004). "Complete sequencing and characterization of 21,243 full-length human cDNAs.". Nat. Genet. 36 (1): 40-5. doi:10.1038/ng1285. PMID 14702039.
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Kappa_Opioid_receptor". A list of authors is available in Wikipedia.
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