Fig. 6.

Recirculation fraction (R_f) of Ca²⁺ in WT (n=5) and gravin-t/t muscles (n=7). R_f was determined from the slopes of the linear relationships between consecutive twitches and their corresponding [Ca²⁺]_i transients at a baseline stimulation rate of 0.5 Hz after potentiation of both stress development and [Ca²⁺]_i transient. Stress _(n) and Stress _(n+1) are two consecutive twitches, and [Ca²⁺]_{i (n)} and [Ca²⁺]_{i (n+1)} refer two consecutive [Ca²⁺]_i transients. [Ca²⁺]_o = 1.0 mM.