The effects of endorphins on mucous glycoprotein secretion from feline airways in vitro.
The effect of opioid peptide hormones on respiratory glycoprotein secretion was investigated in a cat tracheal organ culture system. Dynorphin A (dyn, 10(-5) M), alpha-endorphin (alpha E, 10(-5) M) and morphine sulfate (MS, 10(-4) M) stimulated mucous glycoprotein (MGP) release from airways, whereas all other endorphins tested failed to have such an effect. Dyn did so in a dose dependent manner (10(-5)-10(-7) M) with a peak effect after a one hour incubation. Two sets of data suggest that dyn is acting through the previously described endorphin-kappa receptor: The active binding site of dyn is at the carboxyl end of the peptide; dyn fragment 1-13 stimulated MGP secretion while dyn fragment 1-8 did not. Naloxone in equimolar concentration totally inhibited the dyn response. We, therefore, conclude that the endorphins dyn and alpha E stimulate MGP release and that dyn is probably acting by stimulating kappa receptors.
D000818:Animals; D002415:Cats; D004305:Dose-Response Relationship, Drug; D004399:Dynorphins / Q000494:pharmacology; D004723:Endorphins / Q000494:pharmacology*; D004743:Enkephalin, Leucine / Q000494:pharmacology; D004744:Enkephalin, Methionine / Q000494:pharmacology; D006023:Glycoproteins / Q000378:metabolism; D009020:Morphine / Q000494:pharmacology; D009093:Mucus / Q000378:metabolism*; D009270:Naloxone / Q000494:pharmacology; D009924:Organ Culture Techniques; D012636:Secretory Rate / Q000187:drug effects; D014132:Trachea / Q000378:metabolism*; D018822:alpha-Endorphin; D001615:beta-Endorphin; D018823:gamma-Endorphin
D004723:Endorphins; D006023:Glycoproteins; D009270:Naloxone; D004744:Enkephalin, Methionine; D004743:Enkephalin, Leucine; D001615:beta-Endorphin; D018822:alpha-Endorphin; D018823:gamma-Endorphin; D004399:Dynorphins; D009020:Morphine