Table 1.
In vivo cardiac performance of WT and PLM-KO mice
| WT | PLM-KO | |
|---|---|---|
| Echocardiography | ||
| Body wt, g | 25.3 ± 0.4 (5) | 24.4 ± 0.4 (5) |
| LVIDD, mm | 3.27 ± 0.02 | 3.55 ± 0.06* |
| LVIDS, mm | 1.73 ± 0.13 | 2.03 ± 0.04 |
| ANT, mm | 0.51 ± 0.00 | 0.60 ± 0.00* |
| PWT, mm | 0.54 ± 0.02 | 0.65 ± 0.01* |
| LV mass, mg | 38.5 ± 2.0 | 55.8 ± 1.1* |
| Heart rate, beats/min | 401 ± 18 | 406 ± 13 |
| Ejection fraction, % | 78.9 ± 4.1 | 74.8 ± 1.2 |
| Fractional shortening, % | 47.1 ± 3.7 | 42.8 ± 1.1 |
| Stroke volume, μl | 34.2 ± 1.7 | 39.5 ± 1.8 |
| Cardiac output, ml/min | 13.8 ± 1.0 | 16.0 ± 0.9 |
| In vivo catheterization | ||
| +dP/dt, mmHg/s | 6,728 ± 304 (9) | 7,920 ± 338* (14) |
| Max +dP/dt, mmHg/s | 13,559 ± 896 | 13,642 ± 363 |
| −dP/dt, mmHg/s | 7,189 ± 341 | 8,163 ± 365 |
| Max −dP/dt, mmHg/s | 13,903 ± 1278 | 11,750 ± 933* |
Values are means ± SE for no. of mice in parentheses. WT, wild type; PLM-KO, phospholemman knockout; LV, left ventricular; LVIDD, LV internal dimension at end diastole; LVIDS, LV internal dimension at end systole; ANT, anterior wall thickness; PWT, posterior wall thickness. LV mass is given by the formula: LV mass = 1.04[(ANT + LVIDD + PWT)3 − (LVIDD)3]. Maximal +dP/dt and maximal −dP/dt are peak hemodynamic responses after 25-ng isoproterenol infusion.
*
P < 0.003, PLM-KO vs. WT.