Modulation of hormone-induced calcium oscillations by intracellular pH in rat hepatocytes

Détails

ID Serval
serval:BIB_FF1D22621D84
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Modulation of hormone-induced calcium oscillations by intracellular pH in rat hepatocytes
Périodique
American Journal of Physiology
Auteur(s)
Chatton  J. Y., Liu  H., Stucki  J. W.
ISSN
0002-9513 (Print)
Statut éditorial
Publié
Date de publication
05/1997
Volume
272
Numéro
5 Pt 1
Pages
G954-61
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: May
Résumé
Single isolated rat hepatocytes were used to investigate the influence of intracellular pH (pHi) on hormone-induced cytosolic Ca2+ oscillations, using videofluorescence microscopy. Although pHi did not vary after alpha-adrenergic stimulation, manipulations of pHi induced pronounced alterations in the frequency of oscillations. Increasing the resting pHi with ammonium chloride (5-20 mM), trimethylammonium (2-10 mM), or triethylammonium (1.2-8 mM) reduced the frequency of oscillations. A change in pHi of > 0.25 was sufficient to reversibly inhibit oscillations. This effect could be overcome by increasing the agonist concentration or by adding 8-bromoadenosine 3',5'-cyclic monophosphate, an agent known to potentiate the alpha-adrenergic response. Cellular acidification, obtained by the ammonium prepulse method as well as by application of acetate or the ionophore nigericin, in the continuous presence of agonist was accompanied by a modest frequency increase of the oscillations, leading in some cases to an overstimulated state. This study indicates that pHi, within a range of values expected to occur in vivo (0.1-0.2 pH units), exerts a chronotropic effect on phenylephrine-induced Ca2+ oscillations. In contrast, oscillations induced by ADP or vasopressin were pHi invariant.
Mots-clé
Adrenergic alpha-Agonists/pharmacology Alkalies/metabolism Ammonium Chloride/pharmacology Animals Calcium/*metabolism Hormones/*pharmacology Hydrogen/*metabolism Hydrogen-Ion Concentration Intracellular Membranes/*metabolism Liver/cytology/*metabolism Male Oscillometry Phenylephrine/pharmacology Rats Rats, Wistar
Pubmed
Web of science
Création de la notice
24/01/2008 14:08
Dernière modification de la notice
20/08/2019 17:29
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