The kinetics of Ca++ uptake have been evaluated in 3T3 and SV40-3T3 mouse cells. The data reveal at least two exchangeable cellular compartments in the 3T3 and SV40-3T3 cell over a 50-min exposure to 45Ca++. A rapidly exchanging compartment may represent surface-membrane-localized Ca++ whereas a more slowly exchanging compartment is presumably intracellular. The transition of the 3T3 cell from exponential growth (at 3 day's incubation) to quiescence (at 7 days) is characterized by a 7.5-fold increase in the size of the fast component. Quiescence of the 3T3 cell is also characterized by a 3.2-fold increase in the unidirectional Ca++ influx into the slowly exchanging compartment and a 3.6-fold increase in its size. The increase in size of the slow compartment at quiescence may result from a redistribution of intracellular Ca++ to a more readily exchangeable compartment, possibly reflecting a release of previously bound Ca++. In contrast, no significant change in any of these parameters is observed in the proliferatively active SV40-3T3 cells after corresponding period of incubation, even though these cells attained higher growth densities and underwent postconfluence.
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Article| June 01 1979
Calcium transport and exchange in mouse 3T3 and SV40-3T3 cells.
B J Hazelton
J T Tupper
Online ISSN: 1540-8140
Print ISSN: 0021-9525
J Cell Biol (1979) 81 (3): 538–542.
B J Hazelton, J T Tupper; Calcium transport and exchange in mouse 3T3 and SV40-3T3 cells.. J Cell Biol 1 June 1979; 81 (3): 538–542. doi: https://doi.org/10.1083/jcb.81.3.538
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