Endothelin-3 increases transmission in the rabbit pulmonary parasympathetic nervous system.
The effect of endothelin-3 (ET-3) on the response to parasympathetic nerve stimulation of rabbit isolated bronchus was examined. The site of action of ET-3 in the pulmonary parasympathetic nervous system was also investigated. ET-3 induced a concentration-dependent increase in the response to electrical field stimulation. The response was atropine sensitive and therefore cholinergically mediated. At a concentration of 10 nM, ET-3 increased the response to field stimulation to 205 +/- 42% of the initial response. The effect was concentration-related, as 100 nM further increased this response to 315 +/- 69%. The responsiveness of the tissue to exogenous acetylcholine was not affected by ET-3. Therefore ET-3 has a neuromodulatory role on cholinergic parasympathetic transmission in rabbit airways exerted at a prejunctional site.
McKay
K O
KO
Department of Pharmacology, University of Sydney, New South Wales, Australia.
Armour
C L
CL
Black
J L
JL
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D004558:Electric Stimulation; D016232:Endothelins / Q000494:pharmacology*; D066298:In Vitro Techniques; D008168:Lung / Q000294:innervation*; D010275:Parasympathetic Nervous System / Q000187:drug effects* / Q000502:physiology; D011817:Rabbits; D009435:Synaptic Transmission / Q000187:drug effects* / Q000502:physiology
D016232:Endothelins; D001285:Atropine; D000109:Acetylcholine