Simultaneous measurements of the fractions of Hb and Ca2+ lost from AA RBCs by lysis in hypotonic media at 4 sequential time points during the Ca2+ extrusion stage of the load-extrusion protocol
. | Percent 45Ca2+ lost . | . | . | . | Percent Hb lost . | . | . | . | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Relative tonicity, % . | 4 min . | 4.5 min . | 5 min . | 5.5 min . | 4 min . | 4.5 min . | 5 min . | 5.5 min . | ||||||
| 0 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | ||||||
| 10 | 37.8 | 47.5 | 43.4 | 36.0 | 38.7 | 60.0 | 75.5 | 85.2 | ||||||
| 15 | 15.0 | 25.1 | 29.3 | 27.7 | 18.5 | 50.4 | 68.4 | 83.5 | ||||||
| 20 | 7.5 | 15.4 | 15.0 | 20.1 | 13.0 | 46.5 | 66.5 | 84.1 | ||||||
| 25 | 4.3 | 11.0 | 14.3 | 13.3 | 9.7 | 43.6 | 66.4 | 82.0 | ||||||
| 30 | 4.1 | 9.0 | 9.3 | 11.6 | 8.2 | 42.3 | 64.6 | 81.1 | ||||||
| 35 | 1.6 | 7.7 | 7.2 | 15.1 | 6.8 | 41.3 | 64.2 | 80.3 | ||||||
| 40 | 0.9 | 6.8 | 10.2 | 11.1 | 5.5 | 40.0 | 63.2 | 79.1 | ||||||
| 45 | 1.4 | 6.4 | 10.1 | 12.2 | 4.5 | 35.9 | 58.5 | 68.2 | ||||||
| 50 | 0.3 | 6.3 | 3.0 | 3.1 | 2.6 | 25.4 | 36.5 | 33.9 | ||||||
| 60 | 0.3 | 2.1 | 0.6 | 1.1 | 0.5 | 7.2 | 4.5 | 1.4 | ||||||
| 100 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | ||||||
| Plateau values mean ± SEM | — | 8.2 ± 0.7 | 10 ± 1 | 13 ± 1 | — | 41 ± 1 | 63 ± 1 | 81 ± 1 | ||||||
| Mean [CaT]i, μmol (340 g Hb)−1 | 157 | 73 | 39 | 17 | — | — | — | — | ||||||
. | Percent 45Ca2+ lost . | . | . | . | Percent Hb lost . | . | . | . | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Relative tonicity, % . | 4 min . | 4.5 min . | 5 min . | 5.5 min . | 4 min . | 4.5 min . | 5 min . | 5.5 min . | ||||||
| 0 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | ||||||
| 10 | 37.8 | 47.5 | 43.4 | 36.0 | 38.7 | 60.0 | 75.5 | 85.2 | ||||||
| 15 | 15.0 | 25.1 | 29.3 | 27.7 | 18.5 | 50.4 | 68.4 | 83.5 | ||||||
| 20 | 7.5 | 15.4 | 15.0 | 20.1 | 13.0 | 46.5 | 66.5 | 84.1 | ||||||
| 25 | 4.3 | 11.0 | 14.3 | 13.3 | 9.7 | 43.6 | 66.4 | 82.0 | ||||||
| 30 | 4.1 | 9.0 | 9.3 | 11.6 | 8.2 | 42.3 | 64.6 | 81.1 | ||||||
| 35 | 1.6 | 7.7 | 7.2 | 15.1 | 6.8 | 41.3 | 64.2 | 80.3 | ||||||
| 40 | 0.9 | 6.8 | 10.2 | 11.1 | 5.5 | 40.0 | 63.2 | 79.1 | ||||||
| 45 | 1.4 | 6.4 | 10.1 | 12.2 | 4.5 | 35.9 | 58.5 | 68.2 | ||||||
| 50 | 0.3 | 6.3 | 3.0 | 3.1 | 2.6 | 25.4 | 36.5 | 33.9 | ||||||
| 60 | 0.3 | 2.1 | 0.6 | 1.1 | 0.5 | 7.2 | 4.5 | 1.4 | ||||||
| 100 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | ||||||
| Plateau values mean ± SEM | — | 8.2 ± 0.7 | 10 ± 1 | 13 ± 1 | — | 41 ± 1 | 63 ± 1 | 81 ± 1 | ||||||
| Mean [CaT]i, μmol (340 g Hb)−1 | 157 | 73 | 39 | 17 | — | — | — | — | ||||||
The results are representative of those obtained in 3 similar experiments. The quasi-plateau values were calculated from the measured Hb and 45Ca losses (numbers in bold) in the relative tonicity range from 25% to 45% and used as described in Table 2 to estimate the mean [CaT]i retained within the cells that failed to dehydrate during the postincubation period in LK medium. “Mean [CaT]i” reports the measured mean total RBC Ca2+ content at the indicated time points as shown in Figure 3A.
— indicates not applicable.