Figure 1.

Intravenous administration of TRPM4 inhibitor 9-phenanthrol decreased arterial blood pressure and heart rate. Invasive blood pressure measurement of rats was performed via cannulation of the left carotid artery. TRPM4 inhibitor 9-phenanthrol was administered (shown by unlabeled arrows, in Panel A) through a venous catheter placed in the jugular vein. Consecutive (cumulative) applications were initiated when the blood pressure response stabilized (reached a steady state), usually after 2–3 min. The peak effects observed during the bolus applications are plotted on the graphs. (A) Representative recording; (B) representative recording upon the application of the solvent DMSO alone; (C) systolic and diastolic blood pressure values at the peak of the transient effect of 9-phenanthrol; (D) heart rate at the peak of the transient effect of 9-phenanthrol, where the systolic pressure values were determined. Statistically significant effects upon the cumulative application of 9-phenanthrol (compared to the effect of DMSO (solvent) alone (labeled arrow in panel A), determined by Friedman test) are labeled by the asterisks; (E) effects of repeated DMSO (solvent) application on blood pressure; and (F) heart rate of rats. Graphs show the mean ± SEM. Six animals were tested with 9-phenanthrol (n = 6, panels A,C,D) and a separate six animals were tested with DMSO alone (n = 6, panels B,E,F).