TABLE 1.
Morphometric parameters and metabolic analysis of aging GAMT–/– mice.
| WT | GAMT–/– | |
| Morphology | ||
| Age (weeks) | 76 ± 0.9 | 76 ± 3.2 |
| LV weight (mg) | 106.1 ± 4.4 | 87.0 ± 5∗ |
| RV weight (mg) | 27.2 ± 1 | 23.4 ± 2 |
| Lung weight (mg) | 163.1 ± 5 | 153.4 ± 1 |
| Tibial length (mm) | 18.7 ± 0.1 | 18.2 ± 0.1∗∗ |
| LV/Tibia Length (mg/mm) | 5.6 ± 0.2 | 4.7 ± 0.3∗ |
| LV/Body Weight (mg/g) | 2.6 ± 0.1 | 3.5 ± 0.1*** |
| Myocardial energetic profile | ||
| TAN Pool (nmol/mg protein) | 31.1 ± 2.7 | 40.1 ± 4.9 |
| Creatine (μmol/g whw) | 12.1 ± 0.6 | 0.07 ± 0.01*** |
| Phosphocreatine (μmol/g whw) | 0.8 ± 0.05 | 0.07 ± 0.02*** |
| Guanidinoacetate (μmol/g whw) | 0.3 ± 0.05 | 7.4 ± 0.8*** |
| Phosphoguandinoacetate (μmol/g whw) | 0.2 ± 0.12 | 3.5 ± 0.53*** |
| Triacylglycerol (mM/whw) | 0.05 ± 0.006 | 0.03 ± 0.002∗ |
| Glycogen (glycolsyl units/g whw) | 4.3 ± 0.5 | 4.1 ± 0.83 |
| Plasma metabolites | ||
| Free Fatty Acids (μmol/l) | 541.7 ± 74.8 | 517.1 ± 57.86 |
| 3-hydroxybutyrate (μmol/l) | 247.3 ± 32.05 | 249.6 ± 15.7 |
| Cholesterol (mmol/l) | 3.4 ± 0.6 | 2.0 ± 0.1∗ |
| Triglycerides (mmol/l) | 1.6 ± 0.2 | 0.8 ± 0.1∗∗ |
| High Density Lipoprotein (mmol/l) | 1.6 ± 0.3 | 0.9 ± 0.2 |
| Low Density Lipoprotein (mmol/l) | 1.1 ± 0.3 | 0.8 ± 0.1 |
| Lactate (mmol/l) | 10.2 ± 5.2 | 5.2 ± 2.6 |
| Total Creatine Kinase (IU/l) | 3404 ± 1275 | 936.5 ± 276 |
| Lactate Dehydrogenase (IU/l) | 714.0 ± 71.1 | 871.2 ± 240 |
Whw – wet heart weight, LV – left ventricle, RV – right ventricle, TAN – total adenine nucleotide pool (ATP + ADP + AMP). Morphological parameters (n = 12/group 5F/7M), energetic profile (n = 4–5/group 3F/2M), plasma metabolites (n = 3–5/group 2F/3M). Concentrations of creatine, PCr, guanidinoacetate (GA), and phospho-guanidinoacetate (P-GA) measured by 1H-NMR spectroscopy. Total adenine nucleotide pool (TAN pool = ADP + AMP + ATP) assessed by HPLC. All values are mean ± SEM. Comparisons were made by Student’s t-test. ∗P < 0.05, ∗∗P < 0.01, ∗∗∗P < 0.001.