FIGURE 5.

Cytosolic Ca buffering. [Ca²⁺]_m and d[BCa]/d[Ca] were calculated and fitted to Eq. 2 as described in the text. The K_D and B_max (mean ± SE) for each age are shown in A–C, and were determined by fitting the data set for each myocyte individually. The cumulative data for each age is shown in the graphs. Note that d[BCa]/d[Ca] is the chord buffer power for any given level of cytosolic-free Ca²⁺. N = 5, 8, and 8, for ED5, 11, and 15, respectively. The data are from four experiments for each age and 1–3 cells per experiment. Units of B_max are in μM/liter cell water and K_D values are in μM.