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Calcium waves in mammalian heart: quantification of origin, magnitude, waveform, and velocity
Author(s) -
Takamatsu T.,
Wier W. G.
Publication year - 1990
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.4.5.2307330
Subject(s) - waveform , diffusion , physics , wave propagation , biophysics , chemistry , optics , voltage , biology , thermodynamics , quantum mechanics
A dual, digital, indo‐1 fluorescence imaging system was used to obtain high‐speed ratiometric images of [Ca 2+ ] i waves in single voltage‐clamped mammalian cardiac cells. The spatiotemporal origin of [Ca 2+ ] i waves in depolarized cells was detected as the spontaneous appearance, over 100‐300 ms, of domelike regions of elevated [Ca 2+ ] i , approximately 20 μm in diameter and 300 nM at the center. Images of [Ca 2+ ] i taken at 67‐ms intervals during propagation of [Ca 2+ ] i waves revealed that the [Ca 2+ ] i wave front was 1 ) constant in shape, 2 ) spatially steep, typically rising from 500 to 1200 nM in about 10 μm, and 3 ) propagating at constant velocity, typically 100 μm/s at 22°C. The observed spatial and temporal patterns of origin and propagation of [Ca 2+ ] i waves are consistent with the hypothesis that [Ca 2+ ] i waves arise from propagating Ca 2+ ‐induced release of Ca 2+ mediated by diffusion of cytosolic Ca 2+ . The [Ca 2+ ] i waves are smaller in peak magnitude and can occupy a larger fraction of the cell than thought previously on the basis of indirect observations.— T akamatsu , T.; W ier , W. G. Calcium waves in mammalian heart: quantification of origin, magnitude, waveform, and velocity. FASEB J. 4: 1519‐1525; 1990.