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Dermorphins, Opioid Peptides from Amphibian Skin, Act on Opioid Receptors of Mouse Neuroblastoma x Rat Glioma Hybrid Cells
Author(s) -
Glaser Thomas,
Hübner Karin,
Castiglione Roberto de,
Hamprecht Bernd
Publication year - 1981
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1981.tb06336.x
Subject(s) - dermorphin , opioid peptide , chemistry , (+) naloxone , enkephalin , receptor , opioid , endorphins , opioid antagonist , endocrinology , medicine , stereochemistry , biochemistry , biology
Abstract: Dermorphin and its Hyp 6 analogue are opiate‐like heptapeptides originally discovered in frog skin and characterized by the presence of a d ‐Ala 2 residue in their sequence. They were assayed for their capacity to compete with [ 3 H]Leu‐enkephalin for binding to opioid receptors in membranes of neuroblastoma x glioma hybrid cells. In the presence of 7 n m ‐[ 3 H]Leu‐enkephalin, the concentrations at which they caused 50% inhibition of [ 3 H]enkephalin binding (IC 50 values) are 0.1 μ m and 0.3 μ m , respectively. In contrast, the synthetic l ‐Ala 2 ‐dermorphin shows very low affinity for the opioid receptors. In addition, like other opioid peptides, dermorphin and Hyp 6 ‐dermorphin inhibit the elevation by prostaglandin E, (PGE 1 ) of the level of adenosine 3′:5′‐cyclic monophosphate (cyclic AMP) (IC 50 values 0.2 μ m and 0.4 μ m , respectively). The inhibition is prevented by the opiate antagonist naloxone, l ‐Ala 2 ‐dermorphin is at least three orders of magnitude less potent in inhibiting the PGE 1 ‐evoked increase in the level of cyclic AMP. The results show that peptides with an amino acid sequence quite different from that of the enkephalins can bind to opioid receptors of the hybrid cells.