JPET 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 Hosey, M. M.
Right arrow Articles by Green, R. D.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Hosey, M. M.
Right arrow Articles by Green, R. D.

Differences in the properties of muscarinic cholinergic receptors in the developing chick myocardium

MM Hosey, KK McMahon, AM Danckers, CM O'Callahan, J Wong and RD Green

The number of muscarinic cholinergic receptors detected with [3H]quinuclidinyl benzilate (QNB) was constant in embryonic chick heart membranes but increased 2.5-fold by 3 days posthatching; the KD for [3H]QNB did not change. The affinities of the muscarinic receptors for agonists, as determined in in vitro [3H]QNB competition experiments, differed during development. The IC50 values were lowest for 10- to 14- day embryonic heart receptors, intermediate for 18- to 20-day embryonic receptors and highest for 3- to 7-day newborn heart receptors. These apparent differences in agonist affinity were not overcome by guanine nucleotides or monovalent cations alone, but were greatly diminished in the presence of a combination of guanylylimidodiphosphate plus NH4+. Modeling of [3H]QNB/oxotremorine competition curves indicated the presence of three agonist affinity states in membranes from embryonic heart and two in newborn hearts. The KD values for oxotremorine increased during development. The proportion of receptors displaying the highest affinity for oxotremorine was constant at all ages tested whereas the proportion displaying the lowest affinity decreased from 16% in membranes from 12-day embryonic hearts to zero in newborn hearts. The physiological significance of the differences in the properties of the receptors was investigated by assessing their ability to attenuate adenylate cyclase. The efficacy of agonists to attenuate basal adenylate cyclase increased 1.5-fold after birth, whereas the potency of agonists to produce this effect was similar at all ages tested.

Volume 232, Issue 3, pp. 795-801, 03/01/1985
Copyright © 1985 by American Society for Pharmacology and Experimental Therapeutics




This article has been cited by other articles:


Home page
 J. Biol. Chem.Home page
T. Gao, T. S. Puri, B. L. Gerhardstein, A. J. Chien, R. D. Green, and M. M. Hosey
Identification and Subcellular Localization of the Subunits of L-type Calcium Channels and Adenylyl Cyclase in Cardiac Myocytes
J. Biol. Chem., August 1, 1997; 272(31): 19401 - 19407.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
L. A. McKinnon and N. M. Nathanson
Tissue-specific Regulation of Muscarinic Acetylcholine Receptor Expression during Embryonic Development
J. Biol. Chem., September 1, 1995; 270(35): 20636 - 20642.
[Abstract] [Full Text] [PDF]


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

Copyright © 1985 by the American Society for Pharmacology and Experimental Therapeutics.