delta-opioid receptors inhibit neurogenic intestinal secretion evoked by mast cell degranulation and type I hypersensitivity.
Histamine and the mast cell degranulator, compound 48/80 produced elevations in short-circuit current, an electrical measure of active anion secretion, across porcine ileal mucosa sheets mounted in Ussing chambers. Luminally-applied beta-lactoglobulin produced similar effects in mucosal sheets from cow's milk-sensitized pigs. Their secretory effects were attenuated by blockers of H(1)-histamine receptors, neuronal conduction or epithelial Na(+)/K(+)/Cl(-) cotransport. The delta-opioid agonist [D-Pen(2), D-Pen(5)]enkephalin suppressed mucosal responses to these substances in a naltrindole-reversible manner. Furthermore, submucosal mast cells and delta-opioid receptor-immunoreactive nerve fibers were observed in close juxtaposition. Intestinal neural pathways linking immediate hypersensitivity to secretory host defense appear to express inhibitory delta-opioid receptors.
Poonyachoti
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Department of Veterinary PathoBiology, University of Minnesota Academic Health Center, 1988 Fitch Avenue, St. Paul, Minneapolis, MN 55108-6010, USA.
Brown
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D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D015550:Cell Degranulation; D020881:Enkephalin, D-Penicillamine (2,5)- / Q000494:pharmacology; D005260:Female; D006632:Histamine / Q000494:pharmacology; D007082:Ileum / Q000378:metabolism; D007413:Intestinal Mucosa / Q000378:metabolism*; D008297:Male; D008407:Mast Cells / Q000502:physiology*; D016269:Milk Hypersensitivity / Q000378:metabolism*; D017465:Receptors, Opioid, delta / Q000502:physiology*; D013552:Swine; D003189:p-Methoxy-N-methylphenethylamine / Q000494:pharmacology
D017465:Receptors, Opioid, delta; D003189:p-Methoxy-N-methylphenethylamine; D006632:Histamine; D020881:Enkephalin, D-Penicillamine (2,5)-