Mu-opioid receptors modulate non-cholinergic constrictor nerves in guinea-pig airways.
A role of opioids as inhibitors of the non-adrenergic non-cholinergic (NANC) excitatory nerves has been studied in the guinea-pig bronchi using electrical field stimulation. Morphine and DAGO gave dose-dependent inhibition of NANC contraction, which was reversed by naloxone, whereas the cholinergic nerve and substance P responses were unaffected. [Met5]enkephalin and [Leu5]enkephalin weakly inhibited NANC contraction, whereas dynorphin-(1-13) had no effect. These results suggest that opiates inhibit NANC bronchoconstriction via mu-opioid receptors.
D000818:Animals; D001341:Autonomic Nervous System / Q000502:physiology*; D001980:Bronchi / Q000294:innervation*; D004399:Dynorphins / Q000494:pharmacology; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D004743:Enkephalin, Leucine / Q000494:pharmacology; D004744:Enkephalin, Methionine / Q000494:pharmacology; D004745:Enkephalins / Q000494:pharmacology; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007202:Indicators and Reagents; D008297:Male; D009020:Morphine / Q000494:pharmacology; D009119:Muscle Contraction / Q000187:drug effects; D010446:Peptide Fragments / Q000494:pharmacology; D011957:Receptors, Opioid / Q000502:physiology*; D017450:Receptors, Opioid, mu; D013373:Substance P / Q000494:pharmacology; D014132:Trachea / Q000187:drug effects
D004745:Enkephalins; D007202:Indicators and Reagents; D010446:Peptide Fragments; D011957:Receptors, Opioid; D017450:Receptors, Opioid, mu; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D013373:Substance P; D004744:Enkephalin, Methionine; D004743:Enkephalin, Leucine; C026843:dynorphin (1-13); D004399:Dynorphins; D009020:Morphine