. | . | . | τ f . | . | τ s . | . | ||
---|---|---|---|---|---|---|---|---|
Temp. . | N . | Hz . | SR empty . | SR full . | SR empty . | SR full . | ||
21°C | 5 | 1.4 | 11.47±2.4 | 8.33±1.8* | 35.3±1.2 | 33.6±1.4 | ||
14°C | 9 | 1.0 | 26.1±3.2 | 11.3±1.1* | 161.7±26.1 | 96±5.9* |
. | . | . | τ f . | . | τ s . | . | ||
---|---|---|---|---|---|---|---|---|
Temp. . | N . | Hz . | SR empty . | SR full . | SR empty . | SR full . | ||
21°C | 5 | 1.4 | 11.47±2.4 | 8.33±1.8* | 35.3±1.2 | 33.6±1.4 | ||
14°C | 9 | 1.0 | 26.1±3.2 | 11.3±1.1* | 161.7±26.1 | 96±5.9* |
. | . | . | τ . | . | . | . | |||
---|---|---|---|---|---|---|---|---|---|
Temp. . | N . | Hz . | . | SR empty . | SR full . | . | |||
7°C | 8 | 0.6 | 154.3±17.8 | 119.2±0.60* |
. | . | . | τ . | . | . | . | |||
---|---|---|---|---|---|---|---|---|---|
Temp. . | N . | Hz . | . | SR empty . | SR full . | . | |||
7°C | 8 | 0.6 | 154.3±17.8 | 119.2±0.60* |
Inactivation of L-type Ca2+ channel (ICa) elicited by 200ms square (SQ) pulses were fit with double exponential functions at 14°C and 21°C. τf is the time constant of fast inactivation and τs is the time constant of slow inactivation. At 7°C, inactivation was best fit with a single exponential (τ).
Values are means ± S.E.M. * indicates that the time constants with a steady-state sarcoplasmic reticulum (SR) Ca2+content after 25 pulses are significantly faster than those after release of SR Ca2+ with caffeine (P<0.05, Student's paired t-test).