Deltorphin, also known as deltorphin A and dermenkephalin, is a

naturally occurring A natural product is a natural compound or substance produced by a living organism—that is, found in nature. In the broadest sense, natural products include any substance produced by life. Natural products can also be prepared by chemical sy ...

exogenous In a variety of contexts, exogeny or exogeneity () is the fact of an action or object originating externally. It contrasts with endogeneity or endogeny, the fact of being influenced within a system. Economics In an economic model, an exogeno ...

opioid Opioids are substances that act on opioid receptors to produce morphine-like effects. Medically they are primarily used for pain relief, including anesthesia. Other medical uses include suppression of diarrhea, replacement therapy for opioid use ...

heptapeptide Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. A ...

and thus, exorphin, with the

amino acid sequence Protein primary structure is the linear sequence of amino acids in a peptide or protein. By convention, the primary structure of a protein is reported starting from the amino-terminal (N) end to the carboxyl-terminal (C) end. Protein biosynthe ...

Tyr-D-Met-Phe-His-Leu-Met-Asp-NH₂. Along with the other deltorphins (such as

deltorphin I Deltorphin I, also known as D-Ala2.html" ;"title="small>D-Ala2">small>D-Ala2eltorphin I or deltorphin C, is a naturally occurring, exogenous opioid heptapeptide and hence, exorphin, with the amino acid sequence Tyr-D-Ala-Phe-Asp-Val-Val-Gly-NH2. ...

and

deltorphin II 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. Along with the other deltorphins (such as delt ...

) and the

dermorphin Dermorphin is a hepta-peptide first isolated from the skin of South American frogs belonging to the genus ''Phyllomedusa''. The peptide is a natural opioid that binds as an agonist with high potency and selectivity to mu Opioid receptors. Dermorp ...

s, deltorphin is endogenous to

frog A frog is any member of a diverse and largely carnivorous group of short-bodied, tailless amphibians composing the order Anura (ανοὐρά, literally ''without tail'' in Ancient Greek). The oldest fossil "proto-frog" ''Triadobatrachus'' is ...

s of the genus ''

Phyllomedusa ''Phyllomedusa'' is a genus of tree frogs in the subfamily Phyllomedusinae found in tropical and subtropical South America (south to northern Argentina) and Panama. It has 16 recognised species. Taxonomy The following species are recognised i ...

'' 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. Deltorphin is one of the highest

affinity Affinity may refer to: Commerce, finance and law * Affinity (law), kinship by marriage * Affinity analysis, a market research and business management technique * Affinity Credit Union, a Saskatchewan-based credit union * Affinity Equity Par ...

and most selective naturally occurring opioid peptides known, acting as a very potent and highly specific agonist of the

δ-opioid receptor The δ-opioid receptor, also known as delta opioid receptor or simply delta receptor, abbreviated DOR or DOP, is an inhibitory 7-transmembrane G-protein coupled receptor coupled to the G protein Gi/G0 and has enkephalins as its endogenous lig ...

. Deltorphins have an unusually high blood–brain barrier penetration rate. The nonselective opiate antagonist

naloxone Naloxone, sold under the brand names Narcan (4 mg) and Kloxxado (8 mg) among others, is a medication used to reverse or reduce the effects of opioids. It is commonly used to counter decreased breathing in opioid overdose. Effects begin withi ...

inhibits deltorphin uptake by brain microvessels, but neither the selective δ-opioid antagonist

naltrindole Naltrindole is a highly potent, highly selective delta opioid receptor antagonist used in biomedical research. In May 2012 a paper was published in ''Nature'' with the structure of naltrindole in complex with the mouse δ-opioid G-protein coupled ...

nor a number of opioid peptides with different affinities for δ- or μ-opioid receptors compete with deltorphins for the transport.

References

Analgesics Opioid peptides {{analgesic-stub

See also

References