The mechanism of action of physostigmine at muscarinic receptors of rat myocardium
Orsetti, M.
Bollettino della Societa Italiana di Biologia Sperimentale 62(1): 67-73
1986
ISSN/ISBN: 0037-8771 PMID: 3718728 Document Number: 285616
The interaction of physostigmine (Phy) with muscarinic receptors on the rat heart has been studied. The results indicated that Phy reduces the ventricular automaticity when tested alone and potentiates the negative chronotropic effect of acetylcholine (Ach). The potentiation of Ach effects occurs in the presence of low concentrations of Phy that are ineffective in inhibiting the acetylcholinesterase. It is concluded that Phy, apart from effect arising from inhibition of cholinesterases, acts allosterically as a noncompetitive sensitizator of the Ach in the rat heart.