Submitted on October 16, 2003
Accepted on June 17, 2004
Ratiometric intracellular calcium imaging in the isolated beating rat heart using Indo-1 fluorescence
Otto Eerbeek1*, Egbert G Mik1, Coert J Zuurbier2, Martijn van 't Loo1, Cees Donkersloot2, and Can Ince1
1 Department of Physiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
2 Department of Anesthesiology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
* To whom correspondence should be addressed. E-mail: o.eerbeek{at}amc.uva.nl.
Abnormalities in intracellular calcium (Ca2i+) handling have been implicated as the underlying mechanism in a large number of pathologies in the heart. Study into the relation between Ca2i+ behavior and performance of the whole heart function could provide detailed information into the cellular basis of heart function. In this study we describe a optical ratio imaging set-up and an analysis-method for the beat-to-beat Ca2i+ video-fluorescence images of an Indo-1 loaded, isolated Tyrode perfused beating rat heart. The signal-to-noise ratio and the spatio-temporal resolution (with an optimum of 1 ms and 0.6 mm respectively) made it possible to register different temporal Ca2i+ transients together with left ventricle pressure changes. The Ca2i+ transients showed that Ca2i+ activation propagates horizontally from left to right during sinus rhythm or from the stimulus site during direct left ventricle stimulation. The developed Indo-1 ratio-metric videotechnique allows the imaging of ratio-changes of Ca2i+ with a high temporal (1 msec) and spatial (0.6 mm) resolution in the isolated Tyrode perfused beating rat heart.
