Abstract
Calcium green-2 (Ca green) is a non-ratio-metric fluorescent Ca2+ indicator with an affinity for Ca2+ (dissociation constant Kd=3 μM) that is lower than more commonly used indicators such as fura-2 and fluo-3. This low Ca2+ affinity, coupled with a high quantum yield, allows cells to be loaded with low concentrations of Ca green, avoiding problems of cytosolic Ca2+ buffering and a low signal-to-noise ratio. This communication presents a method for monitoring intracellular [Ca2+] changes in isolated rat ventricular myocytes loaded with Ca green and the fluorescent pH indicator carboxy SNARF-1 (SNARF). SNARF provides a Ca2+-insensitive signal with which Ca green fluorescence can be corrected for cell motion and dye-loading artifacts.
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References
Backx PH, ter Keurs HEDJ (1993) Fluorescent properties of rat cardiac trabeculae micro-injected with fura-2 salt. Am J Physiol 264:H1098–1110
Balke CW, Egan TM, Wier WG (1994) Processes that remove calcium from the cytoplasm during excitation-contraction coupling in intact rat heart cells. J Physiol (Lond) 474:447–462
Baylor SM, Hollingworth S (1988) Fura-2 calcium transients in frog skeletal muscle fibres. J Physiol (Lond) 403:151–192
Baylor SM, Harkins AB, Kurebayashi N (1994) Letter in reply to Westerblad and Alien. Biophys J 66:927–928
Berlin JR, Konishi M (1993) Ca2+ transients in cardiac myocytes measured with high and low affinity Ca2+ indicators. Biophys 165:1632–1647
Bers DM, Lederer WJ, Berlin JR (1990) Intracellular Ca transients in rat cardiac myocytes: role of Na-Ca exchange in excitation-contraction coupling. Am J Physiol 258:C944-C954
Blatter LA, McGuigan JA (1991) Intracellular pH regulation in ferret ventricular muscle: the role of Na-H exchange and the influence of metabolic substrates. Circ Res 68:150–161
Cannell MB, Berlin JR, Lederer WJ (1987) Effect of membrane potential changes on the calcium transient in single rat cardiac muscle cells. Science 238:1419–1423
Cleemann L, Morad M (1991) Role of Ca2+ channel in cardiac excitation-contraction coupling in the rat: evidence from Ca2+ transients and contraction. J Physiol (Lond) 432:283–312
Hove-Madsen L, Bers DM (1992) Indo-1 binding to protein in permeabilized ventricular myocytes alters its spectral and Ca binding properties. Biophys J 63:89–97
Konishi M, Berlin JR (1993) Ca transients in cardiac myocytes measured with a low affinity fluorescent indicator, furaptra. Biophys J 64:1331–1343
Lipp P, Niggli E (1993) Microscopic spiral-waves reveal positive feedback in subcellular calcium signaling. Biophys J 65:2272–2276
Lipp P, Niggli E (1993) Ratiometric confocal Ca2+-measurements with visible wavelength indicators in isolated cardiac myocytes Cell Calcium 14:359–372
Rijkers GT, Justement LB, Griffioen AW, Cambier JC (1990) Improved method for measuring intracellular Ca2+ with fluo-3. Cytometry 11:923–927
Westerblad H, Allen DG (1994) Methods for calibration of fluorescent calcium indicators in skeletal muscle fibers. Biophys J 66:926–927
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Spencer, C.I., Berlin, J.R. A method for recording intracellular [Ca2+] transients in cardiac myocytes using calcium green-2. Pflugers Arch. 430, 579–583 (1995). https://doi.org/10.1007/BF00373895
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DOI: https://doi.org/10.1007/BF00373895