Table 4.
Effect of hypertonic saline and furosemide on excretion of proteins from epithelial sodium channels and aquaporin-2 channels in a randomized, cross-over study of 24 healthy subjects
| Period | Baseline | Hypertonic saline infusion | Post hypertonic saline infusion | ||||
|---|---|---|---|---|---|---|---|
| 0–90 min | 90–150 min | 150–180 min | 180–210 min | 210–240 min | 240–300 min | P (GLM within) | |
| U-AQP2 (ng/minute) | |||||||
| Placebo | 0.81 (0.66;0.93) | 0.85 (0.71;1.05) | 1.00 (0.81;1.31)* | 1.01 (0.87;1.38)* | 1.07 (0.77;1.26)* | 0.98 (0.80;1.09)* | < 0.001 |
| Furosemide | 0.77 (0.66;0.92) | 1.42 (1.18;1.61)* | 1.12 (0.90;1.41)* | 1.14 (0.88;1.46)* | 0.86 (0.72;1.10)* | 0.79 (0.72;0.93) | |
| P (GLM between) | 0.553 | ||||||
| U-AQP2 /creatinine (ng/mmol) | |||||||
| Placebo | 72 (66;84) | 84 (74;87) | 86 (83;104)* | 102 (85;111)* | 90 (77;99)* | 92 (82;98)* | < 0.001 |
| Furosemide | 76 (63;83) | 140 (104;150)* | 100 (91;129)* | 121 (84;132)* | 97 (81;107)* | 88 (64;104)* | |
| P (GLM between) | 0.186 | ||||||
| U-ENaCγ (ng/minute) | |||||||
| Placebo | 0.87 (0.71;1.27) | 0.73 (0.60;1.19) | 0.90 (0.76;1.27) | 0.81 (0.70;1.10) | 0.75 (0.64;1.13) | 0.68 (0.60;1.03)* | 0.399 |
| Furosemide | 0.92 (0.83;1.26) | 0.87 (0.75;1.03) | 1.06 (0.63;1.31) | 0.83 (0.64;1.12) | 0.81 (0.64;1.04)* | 0.73 (0.63;0.93)* | |
| P (GLM between) | 0.806 | ||||||
| U-ENaCγ /creatinine (ng/mmol) | |||||||
| Placebo | 80 (72;97) | 80 (63;90) | 84 (72;98) | 79 (63;87) | 70 (63;89) | 69 (62;81)* | 0.884 |
| Furosemide | 91 (82;99) | 75 (66;131) | 81 (70;116) | 88 (72;16) | 83 (69;107)* | 72 (60;97)* | |
| P (GLM between) | 0.487 | ||||||
| UAER (μg/min) | |||||||
| Placebo | 1 (0;5) | 3 (3;4) | 4 (4;6) | 4 (3;6) | 4 (3;4) | 3 (0;4) | 0.129 |
| Furosemide | 1 (0;5) | 0 (0;9) | 0 (0;10) | 4 (1;7) | 4 (2;6) | 3 (2;5) | |
| P (GLM between) | 0.167 | ||||||
u-AQP2/minute Aquaporin-2 excretion rate, U-AQP2/creatinine creatinine adjusted u-AQP2 excretion, u-ENaCγ/minute excretion of the γ-fraction of the epithelial sodium channel and U-ENaCγ /creatinine creatinine adjusted u-ENACγ, UAER urinary albumin excretion rate. Urine was collected every 30 min in the 90 min baseline period, once after 60 min of hypertonic infusion, and every 30 min 90 min after hypertonic saline infusion and once 150 min after cessation of hypertonic saline infusion. Data from three baseline periods are pooled and shown as one period. Data are shown as medians with 25 and 75 percentiles in brackets. P-value represents probability of difference in response to hypertonic saline (response from baseline to hypertonic saline) between treatments Statistics are performed with a general linear model (GLM), or Wilcoxon signed rank test. Data were logarithmic transformed before GLM was performed. Difference from baseline: * = p < 0.05