Table 1.
Maximal CRAC channel currents, CRAC channel densities, and morphometric parameters of resting, activated, and Jurkat T cells
| T cell type | Ca2+-ICRAC maximal amplitude at −100 mV (pA) | Na+-ICRAC maximal amplitude at −100 mV (pA) | Number of channels per cell* | Cell surface area (µm2)** | Channel surface density (channels/µm2) | Cell diameters (µm)*** | Cell volume (fL)**** |
| Resting | −5.3 ± 0.8 (n = 24) | −26.1 ± 3.0 (n = 19) | ∼1,400 | 198.6 ± 8.8 (n = 24) | ∼7 | 6.4 ± 0.03 (n = 101) | 137.2 ± 2.2 (n = 101) |
| Activated | −7.6 ± 0.8 (n = 32) | −52.0 ± 6.4 (n = 29) | ∼2,000 | 741.1 ± 26.1 (n = 32) | ∼2.7 | 11.8 ± 0.1 (n = 122) | 894 ± 34.9 (n = 122) |
| Jurkat | −12.5 ± 1.3 (n = 25) | −62.4 ± 7.0 (n = 21) | ∼3,300 | 744.2 ± 37.2 (n = 25) | ∼4.4 | 12.3 ± 0.16 (n = 143) | 1049.7 ± 38.3 (n = 143) |
Average ± SE are presented; n is number of cells.
*
Calculated using an estimated value of unitary CRAC channel amplitude of 3.8 fA at −110 mV in 20 mM Ca2+ Ringer solution.36
**
Calculated from Cm values assuming the cell membrane specific capacitance of 0.01 pF µm−2.
***
Measured from transmitted light images as shown in Figure 2D.
****
Calculated from cell diameters measured in transmitted light images.