Renal Afferents

Abstract

Purpose of ReviewThe etiology of hypertension, a critical public health issue affecting one in three US adults, involves the integration of the actions of multiple organ systems, including the renal sympathetic nerves. The renal sympathetic nerves, which are comprised of both afferent (sensory input) and efferent (sympathetic outflow) arms, have emerged as a major potential therapeutic target to treat hypertension and disease states exhibiting excess renal sympathetic activity.Recent FindingsThis review highlights recent advances in both clinical and basic science that have provided new insight into the distribution, function, and reinnervation of the renal sympathetic nerves, with a focus on the renal afferent nerves, in hypertension and hypertension-evoked disease states including salt-sensitive hypertension, obesity-induced hypertension, and chronic kidney disease.SummaryIncreased understanding of the differential role of the renal afferent versus efferent nerves in the pathophysiology of hypertension has the potential to identify novel targets and refine therapeutic interventions designed to treat hypertension.

Dysregulation of the Excitatory Renal Reflex in the Sympathetic Activation of Spontaneously Hypertensive Rat

“…Excessive sympathetic activity plays crucial roles in the pathogeneses of hypertension, chronic heart failure, and chronic kidney disease ( Fitzgerald, 1983 ; Chen et al, 2015 ; Grassi and Ram, 2016 ; Cheng et al, 2019 ). Renal afferent activity may contribute to the sympathetic overactivity in these diseases ( Esler, 2014 ; Frame et al, 2016 ; Kaur et al, 2017 ). Catheter-based radiofrequency renal denervation (RFRD) was used as a therapy for hypertension, chronic kidney disease, and chronic heart failure ( Veelken and Schmieder, 2014 ; Frame et al, 2016 ; Carlstrom, 2017 ).…”

“…Renal afferent activity may contribute to the sympathetic overactivity in these diseases ( Esler, 2014 ; Frame et al, 2016 ; Kaur et al, 2017 ). Catheter-based radiofrequency renal denervation (RFRD) was used as a therapy for hypertension, chronic kidney disease, and chronic heart failure ( Veelken and Schmieder, 2014 ; Frame et al, 2016 ; Carlstrom, 2017 ). However, the renal denervation therapy destroys both the afferent and efferent renal nerves.…”

Angiotensin Type 1 Receptors and Superoxide Anion Production in Hypothalamic Paraventricular Nucleus Contribute to Capsaicin-Induced Excitatory Renal Reflex and Sympathetic Activation

“…Sympathetic over-activity contributes greatly to the pathogenesis and development of several diseases including chronic kidney disease, chronic heart failure, and hypertension [6]. It has been shown that enhanced renal afferent activity in 2-kidney 1-clip hypertensive mice increases blood pressure and sympathetic nerve activity [49], while renal afferent denervation in the rat prevents the progression of chronic renal failure [50].…”

“…It is well known that the renal nerve contains both afferents and efferents. Chemoreceptors in the kidney can be activated by capsaicin, bradykinin, adenosine, and hypertonic NaCl in the renal tissue and pelvis, while mechanoreceptors mainly respond to changes in pelvic pressure [6]. The renal afferent sensory signals contribute to the sympathetic activation in hypertension and chronic heart failure [7,8].…”

Renal nerves and leukocyte infiltration in the kidney during salt-sensitive hypertension

“…Potential mediators of immune cell infiltration in the kidney are the renal sympathetic nerves, where it is known that their actions in the kidney promote hypertension (18). Renal sympathetic denervation (RDN) is currently in clinical trials for treatment of resistant hypertension in humans (3,7,11). Experiments using RDN in different experimental animal models of hypertension show varying effects on hypertension (1,10,18,24,37).…”