Cellular and subcellular heterogeneity of [Ca2+]i in single heart cells revealed by fura-2.
Digital imaging of calcium indicator signals (fura-2 fluorescence) from single cardiac cells has revealed different subcellular patterns of cytoplasmic calcium ion concentration ([Ca2+]i) that are associated with different types of cellular appearance and behavior. In any population of enzymatically isolated rat heart cells, there are mechanically quiescent cells in which [Ca2+]i is spatially uniform, constant over time, and relatively low; spontaneously contracting cells, which have an increased [Ca2+]i, but in which the spatial uniformity of [Ca2+]i is interrupted periodically by spontaneous propagating waves of high [Ca2+]i; and cells that are hypercontracted (rounded up) and that have higher levels of [Ca2+]i than the other two types. The observed cellular and subcellular heterogeneity of [Ca2+]i in isolated cells indicates that experiments performed on suspensions of cells should be interpreted with caution. The spontaneous [Ca2+]i fluctuations previously observed without spatial resolution in multicellular preparations may actually be inhomogeneous at the subcellular level.
D000818:Animals; D001572:Benzofurans; D002118:Calcium / Q000378:metabolism*; D002451:Cell Compartmentation; D016257:Fura-2; D066298:In Vitro Techniques; D009200:Myocardial Contraction; D009206:Myocardium / Q000166:cytology* / Q000378:metabolism; D051381:Rats; D013050:Spectrometry, Fluorescence; D013997:Time Factors
D001572:Benzofurans; D002118:Calcium; D016257:Fura-2