Table 1.
Effects of TAC ± induced NCX1 transgene expression on [Ca2+]i transients
| [Ca2+]o | WT-sham | WT-TAC | NCX1-TAC |
|---|---|---|---|
| Systolic [Ca2+]i, nM | |||
| 0.6 | 146 ± 14 (15) | 137 ± 12* (10) | 136 ± 9 (14) |
| 1.8 | 223 ± 14 (21) | 191 ± 8*(16) | 199 ± 10 (12) |
| 5.0 | 337 ± 19 (20) | 267 ± 12* (17) | 305 ± 19 (12) |
| Diastolic [Ca2+]i, nM | |||
| 0.6 | 100 ± 10 | 98 ± 9 | 96 ± 9 |
| 1.8 | 112 ± 8 | 103 ± 6 | 102 ± 8 |
| 5.0 | 113 ± 8 | 113 ± 5 | 113 ± 11 |
| [Ca2+]i transient amplitude, % increase in fura2 signal | |||
| 0.6 | 8.6 ± 0.9 | 7.9 ± 0.8* | 8.3 ± 0.9# |
| 1.8 | 19.1 ± 0.9 | 17.0 ± 0.9* | 18.6 ± 1.1# |
| 5.0 | 34.9 ± 1.4 | 26.5 ± 1.6* | 32.3 ± 1.8# |
| t1/2 of [Ca2+]i transient decline, ms | |||
| 0.6 | 305 ± 17 | 290 ± 29* | 272 ± 18# |
| 1.8 | 208 ± 11 | 244 ± 16* | 204 ± 10# |
| 5.0 | 168 ± 8 | 207 ± 11* | 158 ± 6# |
Values are means ± SE. Numbers in parentheses are no. of myocytes, without regard to the number of cells contributed by each heart (n=5, 3 and 3 hearts each for WT-sham, WT-TAC and NCX1-TAC, respectively). [Ca2+]o, extracellular Ca2+ concentration; NCX1, cardiac Na+/Ca2+ exchanger; TAC, transverse aortic constriction; WT, wild-type. Data were analyzed by 2-way ANOVA (group, [Ca2+]o).
*
p<0.05, group × [Ca2+]o interaction effect; WT-sham vs. WT-TAC.
#
p<0.02, group or group × [Ca2+]o interaction effect; WT-TAC vs. NCX1-TAC.