FIGURE 2.

Ca²⁺ entry contribution to [Ca²⁺]_rest measured in WT and mdx myotubes. A, effects of removal of extracellular Ca²⁺ (low Ca²⁺ solution and Ca²⁺-free solution) and Gd³⁺ treatment on [Ca²⁺]_rest. B and C, measurements of resting Ca²⁺ entry using Mn²⁺ quench in WT and mdx myotubes. B, representative traces of Fura-2 fluorescence quench by Mn²⁺ measured under resting conditions. C, quantification of the rate of Mn²⁺ quench, between WT and mdx myotubes. Gd³⁺ (20 μm) was added during the experimental determination of Mn²⁺ quench as shown in figure. Data are expressed as mean ± S.E. ***, p < 0.001 versus WT basal value; †††, p < 0.001 versus mdx basal value. §§§, p < 0.001 is indicated in the figure. f.a.u./s, fluorescence arbitrary units/s.