Table 1.
Effects of quinidine on respiratory activity in vitro. Slices with respiratory rhythmic motor output were exposed to quinidine at concentrations shown below.
| Concentration (μM) | Time to stop (min) | Time to washout (min) | Amplitude (norm) | Area (norm) | Half width (ms) | Frequency (Hz) | ||
|---|---|---|---|---|---|---|---|---|
| Control | Quinidine | Control | Quinidine | |||||
| 1 | NA | NA | 1.22 ± 0.13 (p > 0.05) | 0.96 ± 0.15 (p > 0.05) | 588 ± 60 | 437 ± 186 (p > 0.05) | 0.16 ± 0.02 | 0.16 ± 0.02 (p > 0.05) |
| 10 | NA | NA | 0.87 ± 0.06 (p > 0.05) | 0.62 ± 0.07 (p > 0.05) | 575 ± 344 | 332 ± 186 (p > 0.05) | 0.21 ± 0.12 | 0.11 ± 0.04 (p > 0.05) |
| 100 | 46.3 ± 1.7 | 24.4 ± 5.7 | 0 ± 0 | 0 ± 0 | 654 ± 210 | 0 ± 0 | 0.21 ± 0.05 | 0 ± 0 |
| 500 | 15.9 ± 0.5 | 75.4 ± 6.6 | 0 ± 0 | 0 ± 0 | 678 ± 354 | 0 ± 0 | 0.18 ± 0.09 | 0 ± 0 |
| 1000 | 3.1 ± 1.6 | 114.7 ± 44.4 | 0 ± 0 | 0 ± 0 | 370 ± 106 | 0 ± 0 | 0.22 ± 0.03 | 0 ± 0 |
The time to stop respiratory rhythm (time to stop) and the duration of the recovery (time to washout) are reported in minutes. The effects on the amplitude and area of XII burst discharges are normalized with respect to control. The effect on half width of the XII burst is reported in milliseconds and the effect on respiratory frequency is reported in hertz. Paired t-tests are reported for changes in XII amplitude, area, half width, and respiratory frequency. No statistics are reported for 100 μM–1 mM because the respiratory rhythm stopped entirely.