Renal Nerves and Long‐Term Control of Arterial Pressure

Abstract

The objective of this review is to provide an in-depth evaluation of how renal nerves regulate renal and cardiovascular function with a focus on long-term control of arterial pressure. We begin by reviewing the anatomy of renal nerves and then briefly discuss how the activity of renal nerves affects renal function. Current methods for measurement and quantification of efferent renal-nerve activity (ERNA) in animals and humans are discussed. Acute regulation of ERNA by classical neural reflexes as well and hormonal inputs to the brain is reviewed. The role of renal nerves in long-term control of arterial pressure in normotensive and hypertensive animals (and humans) is then reviewed with a focus on studies utilizing continuous long-term monitoring of arterial pressure. This includes a review of the effect of renal-nerve ablation on long-term control of arterial pressure in experimental animals as well as humans with drug-resistant hypertension. The extent to which changes in arterial pressure are due to ablation of renal afferent or efferent nerves are reviewed. We conclude by discussing the importance of renal nerves, relative to sympathetic activity to other vascular beds, in long-term control of arterial pressure and hypertension and propose directions for future research in this field. © 2017 American Physiological Society. Compr Physiol 7:263-320, 2017.

Role of afferent and efferent renal nerves in the development of AngII-salt hypertension in rats

“…Our laboratory and others have studied the role of renal nerves in numerous rat models of hypertension (Osborn and Foss 2017). Much like with human hypertension, RDNX effectively lowers arterial pressure in some models, and not in others (Osborn and Foss 2017).…”

“…Our laboratory and others have studied the role of renal nerves in numerous rat models of hypertension (Osborn and Foss 2017). Much like with human hypertension, RDNX effectively lowers arterial pressure in some models, and not in others (Osborn and Foss 2017). Moreover, we recently developed a method to specifically target afferent renal nerves for ablation that has allowed us to assess the contribution of afferent and efferent renal nerves to the pathogenesis of hypertension (Foss et al 2015).…”

“…; Joyner and Limberg ). More specifically, the renal nerves play an important role in various models of experimental hypertension, and recent clinical trials have shown that ablation of renal nerves (renal denervation; RDNX) lowers arterial pressure in some drug‐resistant patients (Osborn and Foss ). Although the failure of some clinical trials to demonstrate efficacy has raised questions regarding the viability of this therapy (Gulati et al.…”

“…The sympathetic nervous system is one known contributor to the pathogenesis of hypertension (Guyenet 2006;Grassi et al 2015;Joyner and Limberg 2016). More specifically, the renal nerves play an important role in various models of experimental hypertension, and recent clinical trials have shown that ablation of renal nerves (renal denervation; RDNX) lowers arterial pressure in some drug-resistant patients (Osborn and Foss 2017). Although the failure of some clinical trials to demonstrate efficacy has raised questions regarding the viability of this therapy (Gulati et al 2016), the early results of the SPYRAL HTN-OFF MED trial, in which an improved catheter and trial design were used, indicate RDNX is effective in hypertensive patients (Townsend et al 2017).…”

It's what's inside that matters: Getting to the source in renal denervation

“…11 We agree with the authors that RDN of branch RAs needs further investigation, and congratulate them on their study demonstrating the safety of radiofrequency RDN on branch renal arteries, specifically in that there was no histopathological evidence of artery stenosis or kidney injury after ablation. 1 In their study, Sakaoka et al 1 13 Recent studies however suggest it is ablation of afferent nerves that is the putative factor in the antihypertensive effects of RDN. 14,15 The study by Sakaoka et al 1 used a reduction in NE as a surrogate for effective RDN, which is a common methodology in other studies as well.…”