Two Types of Renal Mechanoreceptors

Abstract

Two types of the afferent impulses were recorded in the renal nerves of the mongrel dogs; the ones of low voltage, spontaneously discharging and of slowly adapting units (type A), and the others of higher voltage and threshold, not spontaneously discharging and of rapidly adapting units (type B). Type A impulses consisted of the ones of irregularly discharging and those of regularly discharging at each ascent of intrarenal pressure waves. Type A impulses increased or decreased concomitantly with intrarenal pressure on changing the pressure to different directions from either renal arterial or venous pressures. On the other hand, type B impulses appeared transiently at the fall or rise in the pressure.
The discharges of type B, elicited by elevating intrarenal pressure perfusing Ringer's solution into the pelvis, to abnormally high levels, disap-peared on reducing intrarenal pressure by occluding the renal artery whilst elevating venous pressure.
In conclusions, the renal mechanoreceptors of both types were excited by mechanically induced alterations in intrarenal pressure.