Table 1.
Chemical composition, pH and pCa of six solutions used in preparing and testing myofibrils
| Cardiac rigor | Skeletal rigor | Activation | Relaxation | Blebbistatin + relaxation | ||
|---|---|---|---|---|---|---|
| pH (adjusted by HCl or NaOH) | 7.1 | 7.0 | 7.0 | 7.0 | 7.0 | |
| pCa | – | – | 4.5 | 9.0 | 9.0 | |
| Chemicals (mm) | KCl | 5.00 | 100.60 | 52.31 | 68.68 | 68.68 |
| MgCl2.6H2O | 1.00 | 1.97 | 5.41 | 5.41 | 5.41 | |
| EGTA | 5.00 | 1.05 | 7.20 | 7.20 | 7.20 | |
| Tris | – | 50.02 | – | – | – | |
| Tes | 10.00 | – | – | – | – | |
| Glucose | 7.00 | – | – | – | – | |
| NaCl | 132.00 | – | – | – | – | |
| Imidazole | – | – | 20.27 | 20.27 | 20.27 | |
| ATP | – | – | 6.17 | 6.10 | 6.10 | |
| PCr | – | – | 18.97 | 18.97 | 18.97 | |
| CaCl2 | – | – | 7.00 | 0.014 | 0.014 | |
| Blebbistatin (+/−) | – | – | – | – | 0.08 |
Note that the chemicals in the cardiac rigor solution are different from those of the skeletal rigor solution in an attempt to increase the yield of isolated cardiac myofibrils, as previously documented (Linke et al. 1993). A software program calculated the concentration of chemicals in the rest of the solutions (Fabiato, 1988).