Renal chemoreceptors in the rat.

Abstract

There are afferent nerve fibers responsive to alterations of the kidney's chemical environment in the renal nerves of the rat. In anesthetized, artificially ventilated, male Sprague-Dawley rats, single unit recordings were prepared by dissection of the centrally cut nerves of the right kidney. The stimuli used included occlusion of the renal artery, systemic asphyxia, changes in renal arterial and venous pressures, changes in ureteral pressure, and cyanide infusion. We found a population of sensory nerve fibers whose endings are activated only during markedly impaired renal blood flow (produced by clamping the renal artery, severe hypotension below 40 mm Hg, and prolonged occlusion of the renal vein), and during systemic asphyxia. The same units are not responsive to increases and decreases in systemic arterial pressure (range: 40--190 mm Hg), to ureteral pressure (range: 0--50 mm Hg), or to changes in renal venous pressure. None of the 40 single units studied was spontaneously active; their pattern of activation during renal ischemia always was characterized by trains of impulses. These sensory units have functional properties distinctly different from those of known renal mechanoreceptors. They appear to be a homogeneous group of sensory elements, and we have termed them renal ("R") chemoreceptors. Evidence also is presented which is consistent with the concept that a chemical substance released by or accumulated within the kidney might be the agent activating these chemoreceptors during renal ischemia.

Renal denervation improves cardiac function in rats with chronic heart failure: Effects on expression of β-adrenoceptors

“…It is well known that the mammalian kidney contains several distinct classes of sensory mechanoreceptors and chemoreceptors (18,36) that transmit information to the central nervous system. Stimulation of afferent renal nerves has been shown to evoke alterations in sympathetic nerve activity and arterial blood pressure (31,44).…”

“…Stimulation of afferent renal nerves has been shown to evoke alterations in sympathetic nerve activity and arterial blood pressure (31,44). The excitatory influence may represent an activation of quiescent renal afferents in response to a variety of stimuli (35,36). There are multiple triggers in the HF condition that have the potential for increased activation of the renal afferent nerve activity, including reduced perfusion pressure, increased venous pressure, increased inflammation, and increased oxidative stress to name a few (18).…”

Renal receptors in the rat sensitive to chemical alterations of their environment.

“…In the renal nerves of the rat at least two other populations exist. The fibers of one group are silent under control conditions and are activated only by renal ischemia; those of the other population exhibit a resting discharge and respond markedly to backflow of urine into the renal pelvis (Recordati et al, 1978 characteristics of the first group of receptors which, because of their sensitivity to ischemia and unresponsiveness to mechanical stimuli, were termed renal, "R," chemoreceptors. The second group, on the other hand, was analyzed only superficially.…”

Involvement of Renal Sympathetic Nerve Activation on the Progression of Ischemic Acute Kidney Injury in the Mouse

“…Renal ischemia has been shown to activate the renal sympathetic nerves via stimulation of renal chemoreceptor (13). Renal ischemia causes an acute increase in sympathetic nerve activity, which is mediated through the increased afferent nerve activity from the kidney (14).…”