TABLE 3.
Absolute values of velocity attained during maximal exercise tests before/after surgery, during training (T) and sedentary (S) protocols and performance gain at eight experimental weeks in rats microinjected with Dopamine β-hydroxilase-Saporin (DBHx) or saline (SHAM) into the PVN. Hemodynamic parameters, baroreflex sensitivity, pressure and HR variabilities and respective spectral components at the end of protocols are also shown.
| SHAM-S | SHAM-T | DBHx-S | DBHx-T | |
| Treadmill performance | (n = 7) | (n = 7) | (n = 7) | (n = 7) |
| Before surgery (km/h) | 1.13±0.14 | 1.13±0.19 | 1.13±0.12 | 1.13±0.14 |
| Surgery effects (km/h) | −0.15±0.09 | −0.15±0.15 | −0.15±0.09 | −0.15±0.09 |
| week 0 (km/h) | 0.99±0.19 | 0.98±0.14 | 0.98±0.14 | 0.98±0.13 |
| week 4 (km/h) | 0.90±0.12 | 1.20±0.12 | 0.83±0.08 | 1.20±0.12 |
| week 8 (km/h) | 0.75±0.09 | 1.35±0.09#† | 0.75±0.09 | 1.35±0.09#† |
| Gain (w8–w0) (km/h) | −0.23±0.14 | + 0.38±0.07δ† | −0.23±0.14 | + 0.38±0.08δ† |
| Hemodynamic parameters | (n = 4) | (n = 4) | (n = 4) | (n = 4) |
| MAP (mmHg) | 113±3 | 109±4 | 110±2 | 109±3 |
| HR (b/min) | 352±3 | 321±4° | 351±5 | 350±3* |
| Baroreflex indexes | (n = 4) | (n = 4) | (n = 4) | (n = 4) |
| Bradycardia (bpm/mmHg) | 1.81±0.11 | 2.60±0.07° | 1.61±0.09 | 2.25±0.10° |
| Tachycardia (bpm/mmHg) | 2.47±0.09 | 3.28±0.16° | 2.30±0.14 | 3.06±0.17° |
| Power spectral analysis | (n = 4) | (n = 4) | (n = 4) | (n = 4) |
| SAP variability (mmHg2) | 17.0±1.3 | 13.4±0.7 | 18.0±5.8 | 16.6±1.4 |
| LF-SAP (mmHg2) | 3.1±0.4 | 2.9±0.4 | 4.1±0.9 | 2.8±0.3 |
| VLF-SAP (mmHg2) | 6.9±1.2 | 6.0±0.4 | 6.7±1.7 | 4.3±0.8 |
| PI variability (ms2) | 32.9±2.1 | 36.4±0.9 | 26.9±3.4 | 33.7±9.1 |
| LF-PI (nu) | 29.9±3.2 | 18.2±2.5° | 21.3±0.1 | 24.1±4.8 |
| HF-PI (nu) | 67.6±2.8 | 82.7±2.7° | 78.0±2.5 | 75.8±5.1 |
| LF/HF ratio | 0.47±0.06 | 0.22±0.04° | 0.27±0.04 | 0.34±0.10 |
Values are means ± SEM. Gain represents the difference in treadmill performance between experimental weeks 0 and 8. Treadmill performance (ANOVA with repeated measurements): group F(2,24) = 0,12; P = 0.888; condition F(2,24) = 36.12, P < 0.001; interaction F(2,24) = 0.12, P = 0,888. Hemodynamic parameters, baroreflex indexes and power spectral parameters (Factorial two-way ANOVA): MAP: no significant effects for group, condition or interaction; HR: group F(1,12) = 16.96, P = 0.001, condition F(1,12) = 22.55, P < 0.001; interaction F(1,12) = 15.74, P = 0.002; Reflex bradycardia: group F(1,12) = 8.62, P = 0.013, condition F(1,12) = 58.26, P < 0.001, interaction F(1,12) = 0.64, P = 0.439; Reflex tachycardia: group F(1,12) = 1.60, P = 0.230, condition F(1,12) = 26.56, P < 0.001; interaction F(1,12) = 0.02, P = 0.879. SAP variability: group F(1,12) = 1.79, P = 0.206, condition F(1,12) = 2.21, P = 0.163; interaction F(1,12) = 0.02, P = 0.881; LF-SAP: group F(1,12) = 0.52, P = 0.485, condition F(1,12) = 1.48, P = 0.247; interaction F(1,12) = 0.71, P = 0.417; VLF-SAP: group F(1,12) = 0.76, P = 0.400, condition F(1,12) = 2.11, P = 0.172; interaction F(1,12) = 0.43, P = 0.526; PI variability: group F(1,12) = 0.76, P = 0.400, condition F(1,12) = 1.07, P = 0.322; interaction F(1,12) = 0.11, P = 0.747; LF-PI: group F(1,12) = 0.18, P = 0.675, condition F(1,12) = 2.03, P = 0.182; interaction F(1,12) = 5.32, P = 0.039; HF-PI: group F(1,12) = 0.26, P = 0.620, condition F(1,12) = 3.53, P = 0.085; interaction F(1,12) = 6.34, P = 0.027; LF/HF: group F(1,12) = 0.41, P = 0.534, condition F(1,12) = 2.08, P = 0.175; interaction F(1,12) = 6.56, P = 0.025. Significant differences (P < 0.05) are # vs. week 0, * vs. Sham, ° vs. Sedentary, δ means a change different from zero.