Table 1.
Total Metal Content in Human Cell Types as a Function of Cellular Senescence
| Average metal content (μg/5 × 106 cells)
|
Doubling time of metal content (PD) | Fold change in metal content | ||
|---|---|---|---|---|
| Young | Old | |||
| IMR-90 | ||||
| Fe | 0.050 | 0.511 | 8.9 | 10.2 |
| K | 29.055 | 92.692 | 17.9 | 3.2 |
| Mg | 1.463 | 7.923 | 12.3 | 5.4 |
| Mn | 0.006 | 0.013 | 29.3 | 2.0 |
| Zn | 0.176 | 0.725 | 14.7 | 5.4 |
| HUVEC | ||||
| Fe | 0.027 | 1.361 | 4.4 | 50.2 |
| K | 71.858 | 271.765 | 13.0 | 3.8 |
| Mg | 2.786 | 11.604 | 12.2 | 4.2 |
| Mn | 0.005 | 0.023 | 10.9 | 4.9 |
| Zn | 0.237 | 1.999 | 8.1 | 8.4 |
| SV-IMR-90 | ||||
| Fe | 0.066 | 0.068 | — | 1.0 |
| K | 65.503 | 72.428 | — | 1.1 |
| Mg | 2.014 | 1.941 | — | 1.0 |
| Mn | 0.004 | 0.003 | — | 0.8 |
| Zn | 0.319 | 0.298 | — | 0.9 |
Average metal content was determined from data fit to exponential curve (IMR-90 and HUVEC) or linear curve (SV-IMR-90). Doubling time was determined from exponential curve as 0.69/rate constant (K). For IMR-90, “young” is 25 PD and “old” is 55 PD. For HUVEC, “young” is 35 PD and “old” is 60 PD. SV-IMR-90 values are shown for comparison although the populations do not senesce; “young” is 120 PD and “old” is 200 PD. Slopes of curves for all metals determined in SV-IMR-90 were not significantly different from zero, so no doubling time was calculated.