Deltorphin Explained

Deltorphin, also known as deltorphin A and dermenkephalin, is a naturally occurring, exogenous opioid heptapeptide and thus, exorphin, with the amino acid sequence Tyr-D-Met-Phe-His-Leu-Met-Asp-NH₂.^{[1] [2] [3]} Along with the other deltorphins (such as deltorphin I and deltorphin II) and the dermorphins, deltorphin is endogenous to frogs of the genus Phyllomedusa such as P. bicolor and P. sauvagei where it is produced in their skin, and is not known to occur naturally in any other species.^[4] Deltorphin is one of the highest affinity and most selective naturally occurring opioid peptides known, acting as a very potent and highly specific agonist of the δ-opioid receptor.

Deltorphins have an unusually high blood–brain barrier penetration rate. The nonselective opiate antagonist naloxone inhibits deltorphin uptake by brain microvessels, but neither the selective δ-opioid antagonist naltrindole nor a number of opioid peptides with different affinities for δ- or μ-opioid receptors compete with deltorphins for the transport.^[5]

See also

• Deltorphin I
• Dermorphin

Notes and References

1. Kreil G, Barra D, Simmaco M . Deltorphin, a novel amphibian skin peptide with high selectivity and affinity for delta opioid receptors . European Journal of Pharmacology . 162 . 1 . 123–8 . March 1989 . 2542051 . 10.1016/0014-2999(89)90611-0. etal.
2. Mor A, Delfour A, Sagan S . Isolation of dermenkephalin from amphibian skin, a high-affinity delta-selective opioid heptapeptide containing a D-amino acid residue . FEBS Letters . 255 . 2 . 269–74 . September 1989 . 2551734 . 10.1016/0014-5793(89)81104-4. 6095995 . etal. free .
3. Erspamer V, Melchiorri P, Falconieri-Erspamer G . Deltorphins: a family of naturally occurring peptides with high affinity and selectivity for delta opioid binding sites . Proceedings of the National Academy of Sciences of the United States of America . 86 . 13 . 5188–92 . July 1989 . 2544892 . 297583 . 10.1073/pnas.86.13.5188. 1989PNAS...86.5188E . etal. free .
4. Temussi PA, Picone D, Tancredi T . Conformational properties of deltorphin: new features of the delta-opioid receptor . FEBS Letters . 247 . 2 . 283–8 . April 1989 . 2541018 . 10.1016/0014-5793(89)81353-5. 84259225 . etal. free .
5. Fiori. Anna. Cardelli. Patrizia. Negri. Lucia. Savi. Maria Rosaria. Strom. Roberto. Erspamer. Vittorio. 1997-08-19. Deltorphin transport across the blood–brain barrier. Proceedings of the National Academy of Sciences of the United States of America. 94. 17. 9469–9474. 10.1073/pnas.94.17.9469. 0027-8424. 9256506. 23226. 1997PNAS...94.9469F. free.