Identification of a switching model of calcium cycling in isolated rat hearts.
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.
Op den Buijs
J
J
Dept. of Electr. Eng., Eindhoven Univ. of Technol., Netherlands.
Juloski
A Lj
ALj
Ivanics
T
T
Ligeti
L
L
van der Vusse
G J
GJ
van Riel
N A W
NA