Metformin does not alter the development of SS hypertension. (A) Experimental protocol for BP recording. Continuous BP acquisition via catheters was performed in conscious Dahl SS rats placed on an 8% NaCl diet and subjected to an intravenous infusion of metformin (n = 9) or vehicle (n = 6). (B) Representative systolic (black) and diastolic (red) blood pressure recordings from a vehicle-treated animal. Data were averaged in 1 min intervals. (C) Mean arterial blood pressure (MAP) in the vehicle- and metformin-treated groups. (D) Metformin does not affect MAP circadian dipping increase during development of hypertension. (E) Representative heart rate trace acquired from a vehicle-treated animal. (F) Lack of effect of metformin on heart rate in experimental animals. *,#p < 0.05 vs. 0.4% NaCl; §,$p < 0.05 vs. 8 days on 8% NaCl.