Am J Physiol Cell Physiol Fuel your research with LabChart
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Cell Physiol 260: C851-C860, 1991;
0363-6143/91 $5.00
This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
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 Callewaert, G.
Right arrow Articles by Morad, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Callewaert, G.
Right arrow Articles by Morad, M.

AJP - Cell Physiology, Vol 260, Issue 4 C851-C860, Copyright © 1991 by American Physiological Society

ARTICLES

Regulation of the secretory response in bovine chromaffin cells

G. Callewaert, R. G. Johnson and M. Morad
Department of Physiology, University of Pennsylvania, Philadelphia 19104-6085.

The nicotine-induced current and the Ca2+ current were studied in cultured bovine chromaffin cells using the whole cell patch-clamp technique. The dose-response curve for the nicotinic current gave a dissociation constant of 53 microM and a Hill coefficient of 1.3. Desensitization of the nicotinic current was rapid, with time constants of 22 and 155 ms at 10 microM nicotine. At higher concentrations of nicotine, both time constants decreased somewhat, but the most prominent effect was on the ratio of the two components. Recovery from desensitization was fitted by a single exponential with a time constant of approximately 6 s. Ca2+ current and catecholamine secretion were highly sensitive to changes in extracellular H+ concentration ([H+]o), such that small increases in [H+]o markedly decreased both. The Ca2+ current measured in a chromaffin cell located within a cluster of cells, but not in a single isolated cell, was markedly suppressed when KCl or nicotine was used to induce secretion, suggesting possible local feedback of secretory agents. Among agents secreted by chromaffin cells, ATP, enkephalins, epinephrine, and protons, only protons significantly suppressed the Ca2+ current. Our findings suggest that the secretory response of chromaffin cells may be modulated by rapid desensitization of the nicotinic receptor and a secretion-dependent suppression of the Ca2+ current.


This article has been cited by other articles:


Home page
 Physiol. Rev.Home page
A. G. Garcia, A. M. Garcia-De-Diego, L. Gandia, R. Borges, and J. Garcia-Sancho
Calcium signaling and exocytosis in adrenal chromaffin cells.
Physiol Rev, October 1, 2006; 86(4): 1093 - 1131.
[Abstract] [Full Text] [PDF]

Home page
 Mol. Pharmacol.Home page
G. Abdrakhmanova, J. Dorfman, Y. Xiao, and M. Morad
Protons Enhance the Gating Kinetics of the alpha 3/beta 4 Neuronal Nicotinic Acetylcholine Receptor by Increasing Its Apparent Affinity to Agonists
Mol. Pharmacol., February 1, 2002; 61(2): 369 - 378.
[Abstract] [Full Text] [PDF]

Home page
 Mol. Pharmacol.Home page
J. Zhang, Y. Xiao, G. Abdrakhmanova, W. Wang, L. Cleemann, K.J. Kellar, and M. Morad
Activation and Ca2+ Permeation of Stably Transfected alpha 3/beta 4 Neuronal Nicotinic Acetylcholine Receptor
Mol. Pharmacol., June 1, 1999; 55(6): 970 - 981.
[Abstract] [Full Text]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online