FIGURE 4.

Plots of the relationship between RPP and |ΔG_∼ATP| for nTG, R-92L and R-92W hearts under the three protocols: unpaced +4 mM Ca²⁺, paced +4 mM Ca²⁺ and paced + 300 nM dobutamine. RPP was from supplementary Table 1, |ΔG_∼ATP| was calculated from the data in Table 2. The equations, the inverse of the slopes, the assessment of goodness for the linear fits of data by group and by protocol are summarized in Table 3. (A) hearts from nTG (open circles), R-92L (solid squares), and R-92W (solid triangles) were not paced both at baseline and high workload in response to 4 mM Ca²⁺; (B) hearts from nTG (open circles), R-92L (solid squares) and R-92W (solid triangles) were paced both at baseline and high workload in response to 4 mM Ca²⁺; (C) hearts from nTG (open circles), R-92L (solid squares), and R-92W (solid triangles) were paced at baseline but not paced at high workload in response to 300 nM dobutamine; (D) nTG hearts were perfused by three protocols: unpaced-high calcium (open circles), paced-high calcium (solid squares) and dobutamine (solid triangles); (E) R-92L hearts were perfused by three protocols: unpaced-high calcium (open circles), paced-high calcium (solid squares), and dobutamine (solid triangles); (F) R-92W hearts were perfused by three protocols: unpaced-high calcium (open circles), paced-high calcium (solid squares), and dobutamine (solid triangles). The number of trials is three to six.