Timed inhibition of the renin-angiotensin system suppresses the rise in blood pressure upon awakening in spontaneously hypertensive rats

Spontaneously hypertensive rats (SHR)

Captopril (3, 10, and 30 mg/kg/6 h), enalaprilat (0.3 mg/kg/6 h), or losartan (10 mg/kg/6 h) given as a continuous 6-h infusion during the transition from the light to dark period (LD) for 5 consecutive days

The same drugs given as a continuous 6-h infusion during the transition from the dark to light period (DL) for 5 consecutive days

Blood pressure reduction (average 24-h reduction, increase at awakening, and trough:peak ratios)surrogate