Contrasting Effects of Static and Pulsatile Pressure on Carotid Baroreceptor Activity in Dogs

The purpose of this study was to contrast the effects of static and pulsatile pressure on carotid baroreceptor activity over a wide range of mean arterial pressure. Static and pulsatile pressure were applied to the isolated carotid sinus of dogs anesthetized with chloralose. Recordings were obtained from single baroreceptor units as well as from the whole sinus nerve or a large strand of the nerve. Three observations are reported. First, in single units the pulsatile pressure threshold, which averaged 48 ± 8 (SEM) mm Hg, was far below the static pressure threshold, which averaged 79 ± 8 mm Hg (p