Baroreceptor effects on renal and adrenal nerve activity.

Spontaneous efferent discharges were recorded from nerve filaments dissected from adrenal and renal nerve bundles in the rabbit. Raising of the systemic blood pressure or stimulation of the depressor nerve caused a decrease in discharge rate in these nerve filaments. Portal vein occlusion or elevation of mesenteric venous pressure caused a depression of activity in these nerves. It is suggested that adrenal and renal sympathetic nerve cells receive inputs from baroreceptors in the systemic arterial system and from mechanoreceptors in the portal and mesenteric veins that cause reflex inhibition of activity in these nerve cells.