Dynorphin, a preferential ligand for kappa-opioid receptors, is present in nerve fibers and immune cells within inflamed tissue of the rat.
Exogenous kappa-opioid agonists have been shown to produce peripheral antinociceptive effects in inflamed tissue. This study sought to determine whether endogenous kappa-receptor ligands are present at the site of inflammation. In Freund's adjuvant-induced hindpaw inflammation in the rat, we show, by immunohistochemistry, that dynorphin is detectable within inflammatory cells and in the cutaneous nerves in a similar distribution as calcitonin gene-related peptide, a specific marker for sensory neurons. These findings extend our previous observations in that not only beta-endorphin and Met-enkephalin (mu- and delta-receptor ligands), but also a preferential kappa-ligand is present within inflamed subcutaneous tissue.
Department of Neuropharmacology, Max-Planck-Institut für Psychiatrie, Martinsried, FRG.
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AH
Hassan
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Pzewłocki
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A
Herz
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C
Stein
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000032:analysis; D004399:Dynorphins / Q000032:analysis / Q000378:metabolism*; D005620:Freund's Adjuvant; D007249:Inflammation / Q000503:physiopathology*; D008297:Male; D009412:Nerve Fibers / Q000502:physiology* / Q000648:ultrastructure; D010146:Pain / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar; D017473:Receptors, Opioid, kappa / Q000502:physiology*; D012867:Skin / Q000294:innervation* / Q000473:pathology
D017473:Receptors, Opioid, kappa; D004399:Dynorphins; D005620:Freund's Adjuvant; D015740:Calcitonin Gene-Related Peptide