Change in serum osmolarity (A) with respect to initial value, and total urine output (B) over the course of the experiment for each intervention. Serum osmolarity was determined before the intervention and 1, 2, 3, and 5 h after completion of the 45-min infusion of normal saline (NS) with or without furosemide (FUR), 25% mannitol (MAN), or 4.2% hypertonic saline (HS) with or without furosemide. Differences with respect to initial serum osmolarity were then determined and are displayed. The data used to compute these differences are listed in table 2. Urine outputs represent the total from the beginning of the experiment until the indicated time and are normalized to each animal’s initial weight in units of 100 g. The significance values in the insets (comparison with NS [Ref] noted on the left and mannitol [Ref] on the right) arise from comparisons of the intercepts where the regression line passes through 2.75 h. Thus, these represent comparisons of the overall mean for each group over the course of the experiment. In addition, for serum osmolarity, the slope of the regression line for HS differed from both NS and mannitol (P < 0.001). The slopes for the other interventions did not differ from either NS or mannitol (P ≥ 0.511). For urine output, the slopes of all interventions differed from NS (P < 0.001), whereas there were no differences when compared to mannitol (excluding NS, P > 0.075). All values in the figure are expressed as mean (SD). An asterisk indicates statistical significance using a value of P ≤ 0.007 to account for multiple comparisons as described earlier under Materials and Methods. See text for additional detail.