Table 1.
High-resolution trans-thoracic echocardiography performed on conscious MuRF1−/− and age-matched wild-type mice at baseline, 1 week, and 2 weeks after daily i.p. T3 treatment. Data represent means ± S.E.M. Groups were first analyzed with a one-way analysis of variance, and if significant, analyzed with a Holm–Sidak test for pairwise comparisons.
| MuRF1+/+ Baseline n = 10 | MuRF1−/− Baseline n = 12 | MuRF1+/+ Thyroid hormone 1 week n = 10 | MuRF1−/− Thyroid hormone 1 week n = 12 | MuRF1+/+ Thyroid hormone 2 weeks n = 10 | MuRF1−/− Thyroid hormone 2 weeks n = 12 | |
|---|---|---|---|---|---|---|
| LVEDD (mm) | 3.03 ± 0.11 | 3.08 ± 0.12 | 3.13 ± 0.13 | 3.87 ± 0.15 | 3.11 ± 0.11 | 3.00 ± 0.14 |
| PWTD (mm) | 0.97 ± 0.02 | 1.04 ± 0.04 | 1.12 ± 0.02** | 1.37 ± 0.07**,*** | 1.28 ± 0.05 | 1.58 ± 0.05† |
| AWTS (mm) | 1.77 ± 0.04 | 1.82 ± 0.06 | 1.97 ± 0.02 | 2.23 ± 0.08 | 2.23 ± 0.07 | 2.44 ± 0.06 |
| PWTS (mm) | 1.58 ± 0.01 | 1.65 ± 0.07 | 1.81 ± 0.06 | 2.10 ± 0.08 | 1.93 ± 0.08 | 2.18 ± 0.07 |
| LV Vol; d (L) | 36.5 ± 3.3 | 38.2 ± 3.8 | 39.8 ± 3.7 | 32.6 ± 3.8 | 39.0 ± 3.4 | 36.3 ± 4.1 |
| LV Vol; s (L) | 4.8 ± 0.5 | 5.5 ± 0.8 | 5.8 ± 0.8 | 3.0 ± 0.5† | 5.7 ± 1.0 | 4.0 ± 0.7 |
| LV mass (mg) | 107.3 ± 6.1 | 124.8 ± 11.1 | 139.4 ± 7.6 | 187.8 ± 17.6**,*** | 170.3 ± 8.8** | 237.4 ± 19.8† |
| LV mass/BW (mg/g) | 4.1 ± 0.3 | 4.7 ± 0.2 | 5.2 ± 0.3 | 6.4 ± 0.2**,*** | 5.9 ± 0.3** | 8.0 ± 0.2† |
| BW (g) | 26.1 ± 0.8 | 26.7 ± 2.5 | 27.3 ± 0.7 | 29.0 ± 1.9 | 28.9 ± 1.1 | 29.5 ± 1.8 |
| HR (bpm) | 665 ± 9 | 670 ± 13 | 708 ± 21 | 727 ± 11** | 730 ± 14** | 729 ± 10** |
P < 0.001 vs all other groups.
P < 0.001 vs matched wild type.
P < 0.001 vs MuRF1+/+ and MuRF1−/− baseline.
P < 0.001 vs all other groups except MuRF1−/− with T3 at 2 weeks.
P < 0.001 vs all other groups except MuRF1−/− with T3 at 1 week. HR, heart rate; ExLVD, external left ventricular diameter; bpm, heart beats per minute; AWTD, anterior wall thickness in diastole; AWTS, anterior wall thickness in systole; PWTD, posterior wall thickness in diastole; PWTS, posterior wall thickness in systole; LVEDD, left ventricular end-diastolic dimension; LVESD, left ventricular end-systolic dimension; FS, fractional shortening, calculated as (LVEDD–LVESD)/LVEDD ×100; EF%, ejection fraction calculated as (end Simpson’s diastolic volume – end Simpson’s systolic volume)/end Simpson’s diastolic volume ×100, ND, not determined