Table 2. Power spectrum density of the systolic arterial pressure and HR variability in rats subjected to the SAD or SHAM surgery.
| Temperate (25°C) |
Warm (35°C) |
|||
|---|---|---|---|---|
| Parameters in freely moving rats | SHAM (n = 6) | SAD (n = 6) | SHAM (n = 6) | SAD (n = 6) |
| Systolic arterial pressure variability | ||||
| Systolic pressure (mmHg) | 128 ± 6 | 127 ± 6 | 141 ± 4 | 160 ± 10+* |
| S.D. (mmHg) | 4.8 ± 0.4 | 19.1 ± 3.8* | 7.4 ± 1.1+ | 24.7 ± 2.0* |
| VLF component (mmHg2) | 7.8 ± 0.6 | 34.1 ± 8.6* | 10.6 ± 2.3 | 46.7 ± 6.3* |
| LF component (mmHg2) | 1.9 ± 0.6 | 3.2 ± 0.7 | 5.8 ± 1.1+ | 10.6 ± 1.6+* |
| HF component (mmHg2) | 1.3 ± 0.2 | 1.9 ± 0.1 | 2.6 ± 0.8 | 12.6 ± 6.7+* |
| Heart rate variability | ||||
| Pulse interval (ms) | 175 ± 11 | 134 ± 5* | 151 ± 5 | 122 ± 6* |
| S.D. (ms) | 6.5 ± 1.0 | 5.9 ± 0.6 | 10.1 ± 1.3+ | 7.4 ± 1.0 |
| VLF component (ms2) | 8.4 ± 2.0 | 1.2 ± 0.3* | 5.4 ± 1.4 | 2.2 ± 0.4* |
| LF component (ms2) | 1.4 ± 0.3 | 0.5 ± 0.2* | 1.3 ± 0.3 | 0.7 ± 0.1 |
| HF component (ms2) | 8.0 ± 1.4 | 5.1 ± 0.6 | 11.7 ± 1.7 | 9.3 ± 0.6 |
These parameters were calculated in rats resting in a temperate environment (25° C) or exposed to heat (35° C).
S.D. = standard deviation; VLF = very low frequency; LF = low frequency; HF = high frequency
Values are means ± SEM
* P < 0.05 compared with the SHAM group (in the same environment).
+ P < 0.05 compared with the temperate environment (for the same experimental group).