Affinity and efficacy correlate with chemical structure more than potency does in a series of pentatomic cyclic muscarinic agonists.

Br J Pharmacol. 1985 August; 85(4): 783–786.

PMCID: PMC1916679

P. Angeli, L. Brasili, M. Giannella, F. Gualtieri, and M. Pigini

Abstract

The efficacy and affinity of nine pentatomic cyclic muscarinic agonists were determined on the guinea-pig ileum, according to the method of Furchgott & Bursztyn (1967). The efficacy and affinity of these agonists are affected differently by structural modifications. Our results suggest that a strong dipole oriented in the same direction as that of the hydroxy group of muscarine, or the presence of a polarizable atom in the same position, are important for efficacy.

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