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The effect of ionic strength on cardiac muscarinic receptors
Author(s) -
Burgen A.S.V.
Publication year - 1986
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1986.tb10223.x
Subject(s) - carbachol , ionic strength , muscarinic acetylcholine receptor , chemistry , agonist , receptor , binding site , endocrinology , medicine , biophysics , biochemistry , biology , organic chemistry , aqueous solution
1 The binding of N‐methylscopolamine (NMS) and carbachol to muscarinic receptors in the rat heart has been measured as a function of ionic strength (μ). 2 The binding of NMS was reduced by 3.69 fold for a 10 fold increase in ionic strength. 3 The binding of carbachol was affected in two ways. Firstly, the proportions of the subsites were changed. Above μ = 0.5 M, the superhigh (SH) subsite was converted into the low(L) subsite and above μ = 0.8 M, the high (H) subsite was also converted into the L subsite. Therefore, at high ionic strength, no agonist‐determined subsites can be detected. In addition, increase in ionic strength reduced the binding of carbachol to all subsites and to a much greater extent than for NMS.