Parameter values of the exponential equations describing the recovery of [Ca²⁺]_mito during and after 1 Hz stimulation.

Amplitude (a1, a2 and a3) and rate constants (k1, k2 and k3 in s−1) of the recovery of [Ca2+]mito during and after 1 Hz stimulation (n = number of fibers). *P<0.05: (−Ca)-value vs. corresponding (+ Ca)-value (Bonferroni post-hoc test). ¶Averaged rate constants of slow phase derived from all stimulation frequencies were type-dependent (P<0.05, see text).