Electrophysiological characteristics of renal sensory receptors and afferent renal nerves.

The characteristics of afferent renal nerves are described. Renal baroreceptors are excited by increases in renal arterial pressure, venous pressure or interstitial pressure. Increases in intrapelvic pressure also excite renal afferent nerves though these have not been dissociated from renal tissue pressure receptors or renal chemoreceptors which are also excited by increased intrapelvic pressure with urine. The renal chemoreceptors are excited by renal ischemia, backflow of urine into the renal pelvis and pelvic perfusion with solutions of KCl. Injections of bradykinin and capsaicin also activate these receptors. These sensitivities are discussed with respect to other visceral afferent nerves and their role in renal nociception.