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POSSIBLE INVOLVEMENT OF MUSCARINIC M 1 AND M 3 RECEPTOR SUBTYPES MEDIATING VASODILATION IN ISOLATED, PERFUSED CANINE LINGUAL ARTERIES
Author(s) -
Chiba Shigetoshi,
Tsukada Miyoko
Publication year - 1996
Publication title -
clinical and experimental pharmacology and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 103
eISSN - 1440-1681
pISSN - 0305-1870
DOI - 10.1111/j.1440-1681.1996.tb01189.x
Subject(s) - pirenzepine , muscarinic acetylcholine receptor , vasodilation , acetylcholine , antagonist , phenylephrine , endocrinology , chemistry , medicine , muscarinic acetylcholine receptor m3 , endothelium , pharmacology , receptor , blood pressure
SUMMARY 1. Using the cannula insertion method, muscarinic receptor subtypes were analysed in isolated, perfused canine lingual arteries preconstricted with phenylephrine. 2. Both acetylcholine and McN‐A‐343 induced a profound vasodilation in a dose‐related manner. Acetylcholine‐induced dilations were approximately 1000‐times more potent than McN‐A‐343‐induced dilation. 3. Acetylcholine‐induced dilations were abolished after removal of the endothelium by intraluminal treatment with 1 mg saponin. 4. Acetylcholine‐induced dilations were markedly inhibited by an M 1 /M 3 receptor antagonist, 4‐DAMP. Moreover, they were slightly, but significantly, inhibited by an M 1 antagonist, pirenzepine, but never influenced by an M 2 antagonist, AF‐DX 116. Mc‐N‐A‐343‐induced vasodilations were inhibited by both 4‐DAMP or pirenzepine. 5. These results suggest that there are abundant functional M 3 and a few M 1 receptors in the canine lingual artery that mediate vasodilation and that this vasodilation is dependent on the presence of an intact endothelium.