Figure 1.

Mean arterial pressure (MAP) during the activity period was significantly elevated in mice in both the low K⁺ (A, D) and high K⁺ (C, F) groups. A–C, time course of mean ± s.e.m MAP in mice in the low K⁺ (0.03% K⁺, 3% Na⁺; n = 5), normal K⁺ (0.93% K⁺, 3% Na⁺; n = 4), and high K⁺ (5% K⁺, 3% Na⁺; n = 5) groups compared with MAP in mice on the control diet (0.93% K⁺, 0.24% Na⁺). D–F, mean ± s.e.m MAP_night in mice on the control diet and mice on the experimental diets (*P < 0.05, **P < 0.01, Student's paired t test). Mice were kept on a 12 : 12 h light : dark cycle. Blood pressure recordings were performed for 48 h before the experimental diets were started and again in the same mice at the end of the experimental period.