Table 1.
Blood and urine profiles for Npt2+/+, Npt2+/−, and Npt2−/− mice
| Age, months | Npt2+/+(n) | Npt2+/−(n) | Npt2−/−(n) | |
|---|---|---|---|---|
| Serum Pi, mM | 1 | 2.87 ± 0.07 (20) | 2.78 ± 0.06 (37) | 1.86 ± 0.08 (11)** |
| 2 | 2.35 ± 0.09 (6) | 2.41 ± 0.06 (6) | 1.79 ± 0.06 (7)** | |
| 3 | 2.10 ± 0.08 (9) | 2.30 ± 0.08 (9) | 1.77 ± 0.10 (7)* | |
| 4 | 2.10 ± 0.07 (6) | 2.08 ± 0.18 (6) | 1.65 ± 0.14 (4)* | |
| 5 | 1.94 ± 0.14 (6) | 1.97 ± 0.10 (7) | 1.58 ± 0.03 (4)* | |
| 6 | 1.85 ± 0.09 (5) | 2.02 ± 0.08 (7) | ND | |
| 7 | 1.79 ± 0.08 (4) | 1.88 ± 0.13 (5) | ND | |
| Urine Pi/creatinine† | 9.83 ± 1.15 (26) | 16.62 ± 1.61 (37)* | 24.98 ± 2.02 (21)** | |
| FEIPi‡ | 4.22 ± 0.63 (16) | 6.79 ± 0.75 (28)* | 13.24 ± 1.08 (9)** | |
| Serum total Ca2+, mM | 1 | 2.25 ± 0.03 (20) | 2.21 ± 0.03 (34) | 2.64 ± 0.05 (12)** |
| 2 | 2.19 ± 0.04 (5) | 2.21 ± 0.03 (6) | 2.36 ± 0.05 (7)* | |
| 3 | 2.20 ± 0.05 (9) | 2.13 ± 0.06 (8) | 2.41 ± 0.08 (10)* | |
| 4 | 2.26 ± 0.03 (6) | 2.24 ± 0.05 (6) | 2.42 ± 0.04 (3)* | |
| 5 | 2.00 ± 0.12 (5) | 2.13 ± 0.05 (7) | 2.48 ± 0.02 (3)* | |
| 6 | 2.22 ± 0.09 (3) | 2.32 ± 0.09 (8) | ND | |
| 7 | 2.40 ± 0.06 (2) | 2.23 ± 0.04 (3) | ND | |
| Urine Ca2+/creatinine† | 0.81 ± 0.07 (23) | 1.00 ± 0.12 (36) | 7.90 ± 1.07 (20)** | |
| FEICa+‡ | 0.36 ± 0.04 (15) | 0.52 ± 0.07 (27) | 3.43 ± 0.46 (10)** | |
| Serum 1,25(OH)2D,§ pg/ml | 36.3 ± 9.5 (3) | 73.0 ± 7.2 (3)* | 107.3 ± 11.1 (3)** | |
| Serum PTH,¶ pg/ml | 18.83 ± 1.14 (3) | 19.79 ± 2.31 (3) | 6.98 ± 0.60 (3)** | |
| Serum ALPase, units/liter | 1 | 425 ± 35 (19) | 459 ± 22 (32) | 869 ± 165 (12)** |
| 2 | 179 ± 28 (4) | 208 ± 19 (6) | 361 ± 17 (7)** | |
| 3 | 126 ± 9 (9) | 99 ± 7 (9) | 175 ± 15 (8)* | |
| 4 | 91 ± 6 (6) | 82 ± 8 (6) | 105 ± 10 (4) | |
| 5 | 71 ± 14 (5) | 63 ± 3 (7) | 98 ± 7 (3) | |
| 6 | 92 ± 5 (3) | 64 ± 10 (7) | ND | |
| 7 | 84 ± 0 (2) | 61 ± 12 (3) | ND |
Results are means ± SEM (n, number of mice analyzed). ND, test not performed. ∗, P = 0.05–0.01 for t test comparing mutant mice to Npt2+/+ mice. ∗∗, P < 0.01 for t test comparing mutant mice to Npt2+/+ mice.
†
Assays were done on urine collected from 1- to 3-month-old animals.
‡
FEI indicates the ratio between urine Pi or Ca (mM)/{urine creatinine (mM) × serum Pi or Ca (mM)} (1-month-old animals).
§
1,25(OH)2D assays were done in duplicate on three serum pools from six mice each (1- to 3-month-old animals).
¶
PTH assays were done in duplicate on three serum pools from two or three mice each (2- to 3-month-old animals).