Deltorphin, also known as deltorphin A and dermenkephalin, is a naturally occurring, exogenous opioid heptapeptide and thus,

exorphin Exorphins are exogenous opioid peptides, distinguished from endorphins, or endogenous opioid peptides. Exorphins include opioid food peptides like gluten exorphin and microbial opioid peptides and any other opioid peptide foreign to a host that h ...

, with the amino acid sequence Tyr-D-Met-Phe-His-Leu-Met-Asp-NH₂. Along with the other deltorphins (such as deltorphin I and deltorphin II) and the dermorphins, deltorphin is

endogenous Endogenous substances and processes are those that originate from within a living system such as an organism, tissue, or cell. In contrast, exogenous substances and processes are those that originate from outside of an organism. For example, es ...

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. Deltorphin is one of the highest affinity and most selective naturally occurring opioid peptides known, acting as a very potent and highly specific

agonist An agonist is a chemical that activates a receptor to produce a biological response. Receptors are cellular proteins whose activation causes the cell to modify what it is currently doing. In contrast, an antagonist blocks the action of the ago ...

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 ligan ...

. 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.

References

Analgesics Opioid peptides {{analgesic-stub

See also

References