Perturbation of myo-inositol-1,4,5-trisphosphate levels during agonist-induced Ca2+ oscillations

Détails

ID Serval
serval:BIB_33F653B0EBF1
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Perturbation of myo-inositol-1,4,5-trisphosphate levels during agonist-induced Ca2+ oscillations
Périodique
Biophysical Journal
Auteur(s)
Chatton  J. Y., Cao  Y., Stucki  J. W.
ISSN
0006-3495 (Print)
Statut éditorial
Publié
Date de publication
01/1998
Volume
74
Numéro
1
Pages
523-31
Notes
Journal Article
Research Support, Non-U.S. Gov't --- Old month value: Jan
Résumé
Agonist-induced Ca2+ oscillations in rat hepatocytes involve the production of myo-inositol-1,4,5-trisphosphate (IP3), which stimulates the release of Ca2+ from intracellular stores. The oscillatory frequency is conditioned by the agonist concentration. This study investigated the role of IP3 concentration in the modulation of oscillatory frequency by using microinjected photolabile IP3 analogs. Photorelease of IP3 during hormone-induced oscillations evoked a Ca2+ spike, after which oscillations resumed with a delay corresponding to the period set by the agonists. IP3 photorelease had no influence on the frequency of oscillations. After photorelease of 1-(alpha-glycerophosphoryl)-D-myo-inositol-4,5-diphosphate (GPIP2), a slowly metabolized IP3 analog, the frequency of oscillations initially increased by 34% and declined to its original level within approximately 6 min. Both IP3 and GPIP2 effects can be explained by their rate of degradation: the half-life of IP3, which is a few seconds, can account for the lack of influence of IP3 photorelease on the frequency, whereas the slower metabolism of GPIP2 allowed a transient acceleration of the oscillations. The phase shift introduced by IP3 is likely the result of the brief elevation of Ca2+ during spiking that resets the IP3 receptor to a state of maximum inactivation. A mathematical model of Ca2+ oscillations is in satisfactory agreement with the observed results.
Mots-clé
Animals Calcium/*metabolism Cells, Cultured Computer Simulation Cytosol/metabolism Inositol 1,4,5-Trisphosphate/*metabolism Inositol Phosphates/administration & dosage/pharmacokinetics/pharmacology Kinetics Liver/cytology/drug effects/*metabolism Male Mathematics Microinjections Models, Biological Oscillometry Phenylephrine/*pharmacology Photolysis Rats Rats, Wistar
Pubmed
Web of science
Open Access
Oui
Création de la notice
24/01/2008 14:08
Dernière modification de la notice
20/08/2019 14:20
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