title: Identification of a switching model of calcium cycling in isolated rat hearts.
abstract: So far, the processes involved in regulation of intracellular calcium (Ca/sub i//sup 2+/) in cardiomyocytes have been mainly studied through biochemical and isolated cell analysis. Here, we present a novel technique to model and identify cardiac Ca/sub i//sup 2+/-cycling under physiologically relevant conditions in the intact beating heart. Ca/sub i//sup 2+/ was measured using fluorescence techniques in ex vivo perfused rat hearts. For analysis, we developed a parametric mathematical model, switching between active and inactive calcium release. The kinetic parameters of the two submodes of the model were computed using a recently developed technique from hybrid system identification. Application of the method to control and isoproterenol-stimulated hearts resulted in parameter values within a physiologically reliable range.
authors.affiliation: Dept. of Electr. Eng., Eindhoven Univ. of Technol., Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Op den Buijs
authors.forename: A Lj
authors.initials: ALj
authors.lastname: Juloski
authors.forename: T
authors.initials: T
authors.lastname: Ivanics
authors.forename: L
authors.initials: L
authors.lastname: Ligeti
authors.forename: G J
authors.initials: GJ
authors.lastname: van der Vusse
authors.forename: N A W
authors.initials: NA
authors.lastname: van Riel