Table 2.
Measurements of n = 5 animals at 6 age points (3–17 wk)
| 3 wk | 5 wk | 7 wk | 9 wk | 13 wk | 17 wk | |
|---|---|---|---|---|---|---|
| Body mass, g | 10.3 ± 1.0 | 15.5 ± 1.7 | 17.3 ± 1.3 | 19.0 ± 1.9 | 21.1 ± 2.1 | 22.3 ± 2.2 |
| Dose, nmol | 310 ± 29 | 460 ± 52 | 520 ± 40 | 570 ± 58 | 630 ± 63 | 670 ± 67 |
| Cardiac output, ml/min | 4.5 ± 0.4 | 6.7 ± 0.8 | 7.5 ± 0.6 | 8.3 ± 0.8 | 9.2 ± 0.9 | 9.7 ± 1.0 |
| Renal artery concentration, mM* | 0.64 | 0.64 | 0.64 | 0.64 | 0.64 | 0.64 |
| Inner medulla concentration, mM | 5.6 ± 2.8 | 3.2 ± 1.8 | 3.7 ± 1.0 | 3.5 ± 1.1 | 2.6 ± 1.7 | 2.4 ± 1.1 |
| Concentrating index | 8.8 ± 4.3 | 5.1 ± 2.8 | 5.8 ± 1.5 | 5.5 ± 1.7 | 4.1 ± 2.6 | 3.8 ± 1.7 |
Values are means ± SD. Body mass, dose, cardiac output, renal artery concentration [via modeling arterial input function (AIF)], peak concentration in inner medulla [via quantitative susceptibility mapping (QSM) measurement], and concentrating index (ratio) are shown.
*
Based on modeling the first pass of the AIF with a gamma variate function. Inner medulla concentration vs. age: y = −0.18x + 5.1, R2 = 0.19, P = 0.17. Concentrating index vs. age: y = −0.28x + 7.9, R2 = 0.19, P = 0.17.