Effects of neuropeptide Y on left ventricular function in the conscious rabbit

SUMMARY 1. Changes in arterial pressure, heart rate and left ventricular contractility induced by intravenous injections of neuropeptide Y (NPY; 1–30 μg/kg) were studied in the conscious rabbit. 2. NPY has a brief pressor effect associated with a bradycardia, an increase in left ventricular end diastolic pressure, and a prolonged fall in peak left ventricular dP/dt (LVdP/dt). 3. The haemodynamic changes increase substantially with increasing doses up to 10 μg/kg. Beyond 10 μg/kg there are only slight effects on heart rate or peak LV dP/dt.