Cat. No. 1578
Biological ActivityPotent and selective μ opioid receptor antagonist (Ki values are 0.96 and >10,000 nM for μ and δ receptors respectively). Causes behavioral effects on central administration in vivo. Also increases K+ currents in rat locus ceruleus neurons in vitro via a μ receptor independent mechanism.
(Modifications: Phe-1 = D-Phe, Trp-4 = D-Trp, X-5 = Orn, X-7 = Pen, Disulfide bridge between 2 - 7, Thr-8 = C-terminal amide)
The technical data provided above is for guidance only. For batch specific data refer to the Certificate of Analysis.
All Tocris products are intended for laboratory research use only.
Certificate of Analysis / Product Datasheet / Safety Datasheet
References are publications that support the products' biological activity.
Chieng et al (1996) The μ-opioid receptor antagonist D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP) [but not D-Phe-Cys-Tyr-D-Trp-Arg-Thr-Pen-Thr-NH2 (CTAP)] produces a nonopioid receptor-mediated increase in K+ conductance of rat locus ceruleus neurons. Mol.Pharmacol. 50 650. PMID: 8794906.
Badiani et al (1995) Intra-VTA injections of the mu-opioid antagonist CTOP enhance locomotor activity. Brain Res. 690 112. PMID: 7496796.
Hawkins et al (1989) [3H]-[H-D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2] ([3H]CTOP), a potent and highly selective peptide for mu opioid receptors in rat brain. J.Pharmacol.Exp.Ther. 248 73. PMID: 2563293.
Gulya et al (1988) Central effects of the potent and highly selective mu opioid antagonist D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP) in mice. Eur.J.Pharmacol. 150 355. PMID: 2901358.
If you know of a relevant reference for CTOP please let us know.
Citations are publications that use Tocris products. Selected citations for CTOP include:
Gerhold et al (2015) Pronociceptive and Antinociceptive Effects of Buprenorphine in the Spinal Cord Dorsal Horn Cover a Dose Range of Four Orders of Magnitude. J Neurosci 35 9580. PMID: 26134641.
Beaudry et al (2011) Activation of spinal mu- and δ-opioid receptors potently inhibits substance P release induced by peripheral noxious stimuli. Mol Pharmacol 31 13068. PMID: 21917790.
Margolis et al (2008) δ-opioid receptor expression in the ventral tegmental area protects against elevated alcohol consumption. J Clin Immunol 28 12672. PMID: 19036960.
Börner et al (2006) Cannabinoid receptor type 2 agonists induce transcription of the mu-opioid receptor gene in Jurkat T cells. J Neurosci 69 1486. PMID: 16434616.
View Related Products by Product Action
Keywords: CTOP, supplier, selective, potent, μ-opioid, mu-opioid, antagonists, MOP, Receptors, OP3, Tocris Bioscience, μ Opioid Receptor Antagonist products
Find multiple products by catalog number
Follow @Tocris on Twitter
Tocris is now actively tweeting. For regular updates on news, events and special offers, follow @Tocris on Twitter.