Aquaporin-1 expression is induced in leukocytes of patients with sepsis. (A) Distribution of aquaporin-1 (Aqp1) mRNA levels in septic shock patients at three different time points (baseline, 6 to 12 hours from sepsis and upon septic shock). (B) Distribution of Aqp1 mRNA levels in nonseptic patients at two different time points (baseline and discharge). In patients whose ICU stay was not complicated by sepsis, leukocyte Aqp1 levels at discharge did not exceed admission levels. In patients who developed sepsis, however, Aqp1 levels rose steadily from admission to the onset of sepsis and, up to the onset of septic shock. Data are presented as box plots. Line in the box, median value; box edges, 25th to 75th centiles; whiskers, range of values. *P <0.05, **P <0.01 from baseline values. #P <0.05 from sepsis. Differences within groups were tested by the Friedman test (more than two groups) and the Wilcoxon signed-rank test (two groups).