Table 1.
Cardiac performance in vivo for control and cold-acclimated hearts and the effects of dobutamine addition (300 nM) on cardiac performance of perfused control and cold-acclimated hearts
| Control |
Cold acclimated |
|||
|---|---|---|---|---|
| Untreated | + Dobutamine | Untreated | + Dobutamine | |
| Heart rate (in vivo — bpm) | 430 ± 37 | 418 ± 45 | ||
| Mean arterial pressure (mmHg) | 106 ± 12 | 134 ± 9++ | ||
| RPP (mmHg/min) | 30962 ± 5685 | 29305 ± 3760 | ||
| Cardiac mass (wet mass — g) | 1.51 ± 0.13 | 1.82 ± 0.24++ | ||
| Estimated EDV (μl) | 313 ± 24 | 377 ± 15++ | ||
| Cardiac TAG (μmol/g) | 4.82 ± 1.75 | 4.65 ± 1.60 | ||
| Heart rate (bpm) | 292.4 ± 39.7 | 298.9 ± 51.7 | 247.0 ± 25.5 | 279.2 ± 25.9 |
| Peak systolic pressure (mmHg) | 106.8 ± 12.9 | 127.8 ± 15.2⁎ | 71.8 ± 13.1++ | 88.2 ± 16.0++ |
| Developed pressure (mmHg) | 90.5 ± 11.4 | 113.7 ± 12.6⁎⁎ | 58.3 ± 16.1++ | 75.8 ± 19.8++ |
| + dP/dt (mmHg/s) | 1682.5 ± 130.5 | 2409.8 ± 139.1⁎⁎⁎ | 1419.6 ± 522.6 | 1723.8 ± 454.1++ |
| − dP/dt (mmHg/s) | − 1288.8 ± 94.1 | − 1875.0 ± 71.2⁎⁎⁎ | − 1133.6 ± 415.1 | − 1434.8 ± 484.7 |
Data represents mean ± SD (n = 6). Statistical significance is measured as ANOVA with correction for multiple comparisons and represented as: The effects of cold acclimation; ++P < 0.01: the effects of dobutamine; ⁎P < 0.05, ⁎⁎P < 0.01, ⁎⁎⁎P < 0.001.