M3-Muscarinic Receptor Mediates Prejunctional Inhibition of Noradrenaline Release and the Relaxation in Cat Femoral Artery

Publisher Website
Google Scholar
Abstract
The aim of the present study was to analyse the muscarinic receptors involved in the vasodilation elicited by acetylcholine (ACh) and the carbachol inhibition of electrically-evoked [3H]noradrenaline (NA) release in cat femoral artery. For this purpose, the following receptor antagonists were used, atropine, pirenzepine (M1-antagonist), AF-DX 116 (M2-antagonist) and 4-diphenylacetoxy-N-methylpiperidine methobromide (4-DAMP; M3-antagonist). The order of potency (pA2 values) of these drugs at postjunctional level was: atropine (9·7) ≥ 4-DAMP (9·6) > pirenzepine (7·2) > AF-DX 116 (6·0), and at prejunctional level (pIC50 values) was: 4-DAMP (9·3) > atropine (8·5) > AF-DX 116 (7·1) > pirenzepine (5·9). These findings indicate that the muscarinic receptors mediating the vasodilation induced by ACh and the carbachol inhibition of NA release are of the M3-subtype.

This publication has 29 references indexed in Scilit: