TABLE 2.
Relationship between exponential phases recorded in small-perturbation kinetic experiments on skinned rabbit psoas muscle fibers contracting under isometric conditions.
| Perturbation method | Cross correlation of kinetic phases | ||||
|---|---|---|---|---|---|
| L-jump | Phase 2fast | Phase 2slow | Phase 3 | Phase 4a | Phase 4b |
| Sinusoidal length changes | Process D | Process C | Process B | Process A | |
| T-jump | (τ1) | τ2 | τnegative | τ3 | |
| Pi-jump | kPi | ||||
| ADP-jump | kADP | ||||
An update of correlations proposed by Davis and colleagues (see Davis, 1998) between their L-jump and T-jump phases and phases recorded by others in sinusoidal length change experiments (Zhao and Kawai, 1994), Pi-jump (caged phosphate) experiments (Dantzig et al., 1992) and ADP-jump (caged ADP) experiments (Lu et al., 1993). The phase τ1 is bracketed because it arises indirectly from fiber expansion and not the T-jump (Davis and Harrington, 1993b). Limited data on pressure-jump (P-jump) kinetic phases precludes their inclusion in the table (Fortune et al., 1991; Vawda et al., 1999), however they appear to be qualitatively similar to T-jump data. Phases 4a and 4b are, respectively the temperature dependent and independent components of phase 4 (Davis and Rodgers, 1995a).