Title : Two populations of binding sites for muscarinic antagonists in the rat heart - Hulme_1981_Eur.J.Pharmacol_73_137 |
Author(s) : Hulme EC , Berrie CP , Birdsall NJ , Burgen AS |
Ref : European Journal of Pharmacology , 73 :137 , 1981 |
Abstract :
In a medium containing 100 mM NaCl and 10 mM MgCl2, the binding of antagonists to rat myocardial muscarinic receptors is well described by the simple Langmuir isotherm. However, in low ionic strength media, while a small proportion of the sites (23%) display a small (2-3 fold) increase in antagonist affinity, the majority demonstrate a substantial (ca. 10-fold) decrease. This reduction is reversed by micromolar concentrations of guanylylimidodiphosphate and other GTP analogues, with consequent abolition of the heterogeneity of the receptor population induced by low ionic strength. Millimolar concentrations of Mg2+ but not other cations strongly potentiate this action of the guanine nucleotides. |
PubMedSearch : Hulme_1981_Eur.J.Pharmacol_73_137 |
PubMedID: 7308290 |
Hulme EC, Berrie CP, Birdsall NJ, Burgen AS (1981)
Two populations of binding sites for muscarinic antagonists in the rat heart
European Journal of Pharmacology
73 :137
Hulme EC, Berrie CP, Birdsall NJ, Burgen AS (1981)
European Journal of Pharmacology
73 :137