Figure 3. Analysis of data presented in Fig. 2.

A, plot of the ratios between total amounts of Ca²⁺ influx (Q_υ/2F) and peak amplitudes of [Ca²⁺] transients (d[Ca²⁺]_p,υ) as a function of κ_B‘. Only the ratios measured from those [Ca²⁺] transients which lacked a fast drop phase (•) were used for the fit (continuous line). Accessible cell volume and κ_S were calculated from the slope ( = 1.1 pl) and the x-axis intercept ( = 87) of the regression line, respectively. Ba, plot of κ_P′ estimated from eqn (18) against [Ca²⁺]_rest (the [Ca²⁺] before a given pulse, open symbols) and [Ca²⁺]_peak (filled symbols). Values from fourth to eighth bursts are superimposed. Bb, plot of d[Ca²⁺]_e as a function of [Ca²⁺]_rest. d[Ca²⁺]_e was fitted by 0.42[Ca²⁺]_rest+ 0.0048 (μM). Bc, plot of κ_P′ estimated from eqn (18) as a function of [Ca²⁺]_rest. Values for κ_P′ from different bursts are represented by different symbols. Dotted curves represent fits to values from a given burst. Parameters for the fits, [PV]_T, are displayed in panel C. The continuous curve in Bc is the fit for κ_P′ obtained by pooling values from the last 3 bursts. C, plot of F_FITC (dotted line, left axis) and [PV]_T (○, right axis) estimated in panel Bc against loading time.