MolPharm xPharm- The Comprehensive Pharmacology Reference

Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text (PDF)
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Ehlert, F. J.
Right arrow Articles by Delen, F. M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Ehlert, F. J.
Right arrow Articles by Delen, F. M.

Influence of pH on the binding of scopolamine and N-methylscopolamine to muscarinic receptors in the corpus striatum and heart of rats

FJ Ehlert and FM Delen

Department of Pharmacology, College of Medicine, University of California, Irvine 92717.

The influence of pH on the binding of scopolamine and [3H]N- methylscopolamine to muscarinic receptors in the heart and corpus striatum was investigated. The specific binding of [3H]N- methylscopolamine in the heart and corpus striatum was relatively insensitive to pH over the range of 6 through 10 but decreased markedly below pH 6.0. This reduction in binding was attributed to a reversible decrease in the observed affinity without an effect on the binding capacity. The data are consistent with the postulate that [3H]N- methylscopolamine competes with hydrogen ions for an acidic group on the muscarinic receptor that has a pKA of approximately 5.5 in both the heart and corpus striatum. When measured by competitive inhibition of the binding of [3H]N-methylscopolamine, the affinity of scopolamine decreased relative to that of [3H]N-methylscopolamine as the pH increased from 6 to 10, confirming that it is primarily the protonated form of scopolamine that binds with muscarinic receptors.

Volume 38, Issue 1, pp. 143-147, 07/01/1990
Copyright © 1990 by American Society for Pharmacology and Experimental Therapeutics




This article has been cited by other articles:


Home page
 Biophys. JHome page
K. A. Selz, A. J. Mandell, M. F. Shlesinger, V. Arcuragi, and M. J. Owens
Designing Human m1 Muscarinic Receptor-Targeted Hydrophobic Eigenmode Matched Peptides as Functional Modulators
Biophys. J., March 1, 2004; 86(3): 1308 - 1331.
[Abstract] [Full Text] [PDF]

Home page
 J. Pharmacol. Exp. Ther.Home page
J. E. Porter and D. M. Perez
Influence of a Lysine 331 Counterion on the pKa of Aspartic Acid 125: Evidence for a Salt-Bridge Interaction and Role in alpha 1b-Adrenergic Receptor Activation
J. Pharmacol. Exp. Ther., January 1, 2000; 292(1): 440 - 448.
[Abstract] [Full Text]


Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
All ASPET Journals Molecular Pharmacology Pharmacological Reviews
Molecular Interventions Drug Metabolism and Disposition

Copyright © 1990 by the American Society for Pharmacology and Experimental Therapeutics