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 Pauwels, P. J.
Right arrow Articles by Leysen, J. E.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Pauwels, P. J.
Right arrow Articles by Leysen, J. E.

Depolarization of chick myotubes triggers the appearance of (+)-[3H]PN 200-110-binding sites

PJ Pauwels, HP Van Assouw and JE Leysen

Department of Biochemical Pharmacology, Janssen Research Foundation, Beerse, Belgium.

Regulation of the appearance of dihydropyridine-binding sites was studied in primary cultures of chick myotubes. Labeling of surface dihydropyridine-binding sites on intact myotubes at 37 degrees was achieved with (+)-[3H]PN 200-110. The appearance of the sites was prevented in a calcium-free medium using 1.8 mM EGTA, in accordance with the presumed Ca2+ dependency of the appearance of dihydropyridine- binding sites in skeletal muscle cells. Chronic treatment of myotubes with isoproterenol or various other drugs did not modulate either the Bmax or Kd value of the (+)-[3H]PN 200-110 binding to the membrane preparation of treated myotubes (control values were: Kd = 0.16 nm, Bmax = 556 fmol/mg of protein), suggesting a lack of heterologous regulation via beta-adrenergic receptor stimulation. However, depolarization of intact myotubes, either by 47 mM K+ or 10(-5) M veratridine, provoked a 3-fold increase in the Bmax value of (+)-[3H]PN 200-110 binding measured on the intact muscle cells without affecting the Kd value. The effect was reversed upon repolarization of the cells. Depolarizing conditions did not affect the binding on a membrane preparation of the myotubes. Hence, depolarization appeared to specifically trigger the appearance of (+)-[3H]PN 200-110 binding sites on intact myotubes; several hypotheses which could explain the involved mechanism are discussed.

Volume 32, Issue 6, pp. 785-791, 12/01/1987
Copyright © 1987 by American Society for Pharmacology and Experimental Therapeutics




This article has been cited by other articles:


Home page
 J. Gen. Physiol.Home page
R. Araya, J. L. Liberona, J. C. Cardenas, N. Riveros, M. Estrada, J. A. Powell, M. A. Carrasco, and E. Jaimovich
Dihydropyridine Receptors as Voltage Sensors for a Depolarization-evoked, IP3R-mediated, Slow Calcium Signal in Skeletal Muscle Cells
J. Gen. Physiol., December 30, 2002; 121(1): 3 - 16.
[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 © 1987 by the American Society for Pharmacology and Experimental Therapeutics