Intracellular calcium handling heterogeneities in intact guinea pig hearts.

Détails

ID Serval
serval:BIB_91FF329739AF
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Intracellular calcium handling heterogeneities in intact guinea pig hearts.
Périodique
American Journal of Physiology. Heart and Circulatory Physiology
Auteur(s)
Katra R.P., Pruvot E., Laurita K.R.
ISSN
0363-6135
Statut éditorial
Publié
Date de publication
02/2004
Peer-reviewed
Oui
Volume
286
Numéro
2
Pages
H648-656
Langue
anglais
Notes
Publication types: In Vitro ; Journal Article
Résumé
Regional heterogeneities of ventricular repolarizing currents and their role in arrhythmogenesis have received much attention; however, relatively little is known regarding heterogeneities of intracellular calcium handling. Because repolarization properties and contractile function are heterogeneous from base to apex of the intact heart, we hypothesize that calcium handling is also heterogeneous from base to apex. To test this hypothesis, we developed a novel ratiometric optical mapping system capable of measuring calcium fluorescence of indo-1 at two separate wavelengths from 256 sites simultaneously. With the use of intact Langendorff-perfused guinea pig hearts, ratiometric calcium transients were recorded under normal conditions and during administration of known inotropic agents. Ratiometric calcium transients were insensitive to changes in excitation light intensity and fluorescence over time. Under control conditions, calcium transient amplitude near the apex was significantly larger (60%, P < 0.01) compared with the base. In contrast, calcium transient duration was significantly longer (7.5%, P < 0.03) near the base compared with the apex. During isoproterenol (0.05 microM) and verapamil (2.5 microM) administration, ratiometric calcium transients accurately reflected changes in contractile function, and, the direction of base-to-apex heterogeneities remained unchanged compared with control. Ratiometric optical mapping techniques can be used to accurately quantify heterogeneities of calcium handling in the intact heart. Significant heterogeneities of calcium release and sequestration exist from base to apex of the intact heart. These heterogeneities are consistent with base-to-apex heterogeneities of contraction observed in the intact heart and may play a role in arrhythmogenesis under abnormal conditions.
Mots-clé
Animals, Calcium/physiology, Fluorescent Dyes, Guinea Pigs, Heart/anatomy &amp, histology, Heart/drug effects, Indoles, Intracellular Space/physiology, Isoproterenol/pharmacology, Light, Microscopy, Fluorescence, Models, Animal, Models, Cardiovascular, Myocardium/cytology, Reproducibility of Results, Verapamil/pharmacology
Pubmed
Web of science
Création de la notice
28/01/2008 11:04
Dernière modification de la notice
20/08/2019 15:55
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