Table 1.

Metabolic cage study of Continuous Na-depleted mice at 16 wk of age

End Point	0.04% Na (n = 8)	0.30% Na (n = 7)	P Value
Body mass, g	22.18 ± 0.44	24.03 ± 0.52	0.02
Fat-free mass, g	17.90 ± 0.39	18.81 ± 0.33	0.11
Fat mass, g	4.28 ± 0.12	5.22 ± 0.22	<0.01
Fat, % total mass	19.3 ± 0.5	21.7 ± 0.6	<0.01
Total body water, mL	13.11 ± 0.29	13.77 ± 0.24	0.11
Hydration, % total mass	59.1 ± 0.4	57.3 ± 0.4	<0.01
Food consumed, kcal/day	13.97 ± 0.35	12.52 ± 0.60	0.05
Digestive efficiency, %	84.8 ± 0.6	84.3 ± 0.5	0.48
Calories absorbed, kcal/day	11.85 ± 0.34	10.55 ± 0.50	0.04
Energy efficiency, Δmg body mass/Σ kcal absorbed	18.8 ± 0.8	24.9 ± 1.7	<0.01
Water intake, mL/day	3.56 ± 0.26	3.31 ± 0.26	0.51
Total Na intake, mEq/day	0.053 ± 0.001	0.371 ± 0.018	<0.01
Urine Na concentration, mmol/L	3.6 ± 1.1	294.5 ± 28.3	<0.01
Na eliminated to urine, mEq/day	0.005 ± 0.001	0.344 ± 0.016	<0.01
Na eliminated to feces, mEq/day	0.020 ± 0.003	0.108 ± 0.008	<0.01
Total K intake, mEq/day	0.318 ± 0.008	0.291 ± 0.014	0.10
Urine K concentration, mmol/L	255.1 ± 22.2	254.2 ± 15.1	0.98
K eliminated to urine, mEq/day	0.402 ± 0.038	0.304 ± 0.023	0.06
K eliminated to feces, mEq/day	0.050 ± 0.009	0.035 ± 0.004	0.15
Urine osmolality, mosmol/kgH2O	2,278 ± 308	3,169 ± 233	0.04
Total daily osmolytes to urine, mosmol/day	3.35 ± 0.14	3.75 ± 0.21	0.12
Urine volume, mL/day	1.69 ± 0.26	1.22 ± 0.11	0.13
Water in feces, g/day	0.103 ± 0.006	0.089 ± 0.005	0.10
Water in feces, % feces mass	33.4 ± 0.6	32.5 ± 1.1	0.47

Data reported as means ± SE. Comparisons were performed by independent 2-tailed t test.