Table 1.
Parameters of the voltage dependence of activation and inactivation for T-type and L-type Ca2+ currents
| Voltage Dependence | T-type Current |
L-type Current |
||
|---|---|---|---|---|
| Activation | Inactivation | Activation | Inactivation | |
| Control “Early” | ||||
| V1/2 | −33.8±2.2 (17) | −72.4±1.7 (17) | −14.7±1.3 (13) | −38.7±8 (9) |
| k | 9.5±0.8 | −5.7±0.6 | 4.9±0.3 | −10.3±0.8 |
| AR | ||||
| V1/2 | −14.3±1.3‡ (12) | −63.9±2.8† (12) | −11.2±2.7 (11) | −33.7±8 (4) |
| k | 8±0.7 | −7.8±0.9* | 4.3±0.2 | −10.2±2.8 |
| T24R | ||||
| V1/2 | −25.1±1.9† (6) | −68.2±2.8 (6) | −17.1±1.3 (10) | −39.7±3 (5) |
| k | 9.8±0.6 | −7.7±0.6* | 4.5±0.4 | −12.6±3.4 |
| Control “Late” | ||||
| V1/2 | −28.5±1.8*(11) | −67.7±1.4*(11) | −17.5±1.7 (9) | −28.3±0.5 (9) |
| k | 9.7±0.8 | −8.4±0.7* | 5.1±0.4 | −9.8±1.3 |
| CR | ||||
| V1/2 | −26.8±2.5*(17) | −63.7±2 (17) | −19.3±0.9 (12) | −34.8±2.8 (12) |
| k | 7.3±0.7* | −6.9±0.6 | 4.4±0.5 | −8.2±1 |
Values are means ± SE for (n) recordings. AR, acute reoxygenation; T24R, 24 h of reoxygenation; CR, chronic reoxygenation; V1/2, half-activation voltage; k, slope. V1/2 and k values are derived from Boltzmann fit.
*
P < 0.05,
†
P < 0.01,
‡
P < 0.001. Statistical significance is calculated vs. “early” control myocytes.