Functional evidence that acetylcholine release from Auerbach's plexus of guinea-pig ileum is modulated by alpha 2A-adrenoceptor subtype.
The effects of alpha 2-adrenoceptor ligands on electrically stimulated [3H]acetylcholine release from longitudinal muscle strips of guinea-pig ileum were examined. Xylazine or oxymetazoline reduced the release of [3H]acetylcholine in a concentration-dependent manner, both these actions being antagonized by idazoxan, CH 38083, or WB 4101. Prazosin, considered as an alpha 2B-adrenoceptor antagonist, failed to modify the inhibitory effects of xylazine or oxymetazoline. It is concluded that the alpha 2-adrenoceptors involved in the modulation of acetylcholine release from cholinergic axon terminals of guinea-pig ileum are of the alpha 2A subtype.
Blandizzi
C
C
Institute of Medical Pharmacology, University of Pisa, Italy.
Doda
M
M
Tarkovács
G
G
Del Tacca
M
M
Vizi
E S
ES
D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D001369:Axons / Q000378:metabolism / Q000648:ultrastructure; D002794:Choline / Q000502:physiology; D004558:Electric Stimulation; D005260:Female; D006168:Guinea Pigs; D007082:Ileum / Q000294:innervation*; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D009130:Muscle, Smooth / Q000294:innervation; D009197:Myenteric Plexus / Q000378:metabolism* / Q000648:ultrastructure; D009411:Nerve Endings / Q000378:metabolism; D010109:Oxymetazoline / Q000494:pharmacology; D011942:Receptors, Adrenergic, alpha / Q000145:classification / Q000502:physiology*; D014316:Tritium; D014991:Xylazine / Q000494:pharmacology
D011942:Receptors, Adrenergic, alpha; D014316:Tritium; D014991:Xylazine; D010109:Oxymetazoline; D002794:Choline; D000109:Acetylcholine