Atomoxetine changes rat's HR response to stress from tachycardia to bradycardia via alterations in autonomic function.

Atomoxetine is a central norepinephrine reuptake inhibitor used to treat attention deficit hyperactivity disorder. We tested the effects of atomoxetine upon the heart rate (HR) and mean arterial blood pressure (mBP) response to aversive conditioning. In Protocol 1 the mBP and HR responses to a stress (15s tone followed by shock) were tested in 8 Sprague-Dawley rats given saline pretreatment for 3 days; the rats' responses were then tested for 3 additional days following atomoxetine (1mg/kg, sc).

Parasympathetic response to acute stress is attenuated in young Zucker obese rats.

We compared arterial blood pressure (BP) and heart rate (HR) control in 9- to 11-week old obese Zucker rats (n=10; weight=452+/-45 g, average+/-SD) to age-matched, lean Zucker animals (n=13; weight=280+/-46 g). BP was measured by indwelling catheter. Baseline pressure was 113.