The estimates were applied to 3 samples taken at the indicated times after ionophore (A23187) addition during the Ca²⁺ extrusion stage of the load-extrusion protocol (Figure 3A) and are representative of the ranges found in 3 similar experiments. The results in the table may be read and interpreted as illustrated in the following example using the 5-minute data; at 5 minutes, in the plateau region of relative tonicities (25% to 45%, Table 1) the mean lysis-induced losses of Hb and ⁴⁵Ca were 63% and 10%, respectively (Figure 3B). Since the mean [Ca_T]_i in the cell population is partitioned between dehydrated and nondehydrated cells, mean − [Ca_T]_i = f_d mean − ([Ca_T]_i)_d + f_nd mean − ([Ca_T]_i)_nd, where f_d and f_nd represent the fractions of dehydrated (d) and nondehydrated (nd) cells, respectively, and mean − ([Ca_T]_i)_{(d or nd)} is the mean Ca²⁺ content within each d or nd subpopulation. Continuing with the 5-minute example, 10% of 39 μmol (340 g Hb)⁻¹ is within 63% nondehydrated cells and 90% of 39 μmol (340 g Hb)⁻¹ is within 37% of dehydrated cells, rendering mean − ([Ca_T]_i)_d = 95 and mean − ([Ca_T]_i)_nd = 6.2 in units of μmol (340 g Hb)⁻¹.