Effect of tolvaptan on bBP during inhibition of the NO system. Values are mean ± SEM. Baseline brachial blood pressure (bBP) was defined as a mean of the four measurements 30 min prior to L-NMMA infusion. A stable bBP was achieved for the last 40 min of L-NMMA infusion. A mean of the six measurements from last 40 minutes of L-NMMA infusion was used to calculate changes from baseline. Post-hoc Bonferoni test was used for comparison of the mean of the last 40 min of infusion vs. baseline (p = 0.011 in placebo vs p < 0.0001 in tolvaptan). Paired t-test was performed for comparison of the last 40 min of infusion vs. baseline between treatment groups.