Modulation of acetylcholine release from parasympathetic nerves innervating guinea-pig and human trachea by endomorphin-1 and -2.
Endomorphin-1 and -2 (mu-opioid receptor agonists) produced a concentration-dependent and naloxone-sensitive inhibition of cholinergic contractile responses in guinea-pig trachea (at 10 microM, 46.1 +/- 8.0% and 33.8 +/- 8.6%, respectively). Endomorphin-1 and -2 also inhibited electrically-evoked acetylcholine release from cholinergic nerves innervating guinea-pig (at 0.1 microM, 41.8 +/- 10.9%; at 1 microM 60.1 +/- 6.3%, respectively) and human trachea (at 10 microM, 76.2 +/- 18.1%, and 77.7 +/- 14.3%, respectively). Naloxone prevented the inhibition by endomorphin-1 and -2 in both guinea-pig and human trachea, suggesting that these peptides can inhibit cholinergic, parasympathetic neurotransmission to the airways via the activation of classical opioid receptors.
Patel
H J
HJ
Thoracic Medicine, Imperial College School of Medicine at the National Heart and Lung Institute, London, UK.
Venkatesan
P
P
Halfpenny
J
J
Yacoub
M H
MH
Fox
A
A
Barnes
P J
PJ
Belvisi
M G
MG
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D006801:Humans; D008297:Male; D009119:Muscle Contraction / Q000187:drug effects; D009270:Naloxone / Q000494:pharmacology; D009842:Oligopeptides / Q000494:pharmacology*; D010275:Parasympathetic Nervous System / Q000187:drug effects; D017450:Receptors, Opioid, mu / Q000819:agonists*; D014132:Trachea / Q000187:drug effects* / Q000294:innervation / Q000502:physiology
D009842:Oligopeptides; D017450:Receptors, Opioid, mu; C105293:endomorphin 1; D009270:Naloxone; C105294:endomorphin 2; D000109:Acetylcholine