scholarly journals Does glucagon-like peptide-1 induce diuresis and natriuresis by modulating afferent renal nerve activity?

2019 ◽  
Vol 317 (4) ◽  
pp. F1010-F1021 ◽  
Author(s):  
Kenichi Katsurada ◽  
Shyam S. Nandi ◽  
Neeru M. Sharma ◽  
Hong Zheng ◽  
Xuefei Liu ◽  
...  

Glucagon-like peptide-1 (GLP-1), an incretin hormone, has diuretic and natriuretic effects. The present study was designed to explore the possible underlying mechanisms for the diuretic and natriuretic effects of GLP-1 via renal nerves in rats. Immunohistochemistry revealed that GLP-1 receptors were avidly expressed in the pelvic wall, the wall being adjacent to afferent renal nerves immunoreactive to calcitonin gene-related peptide, which is the dominant neurotransmitter for renal afferents. GLP-1 (3 μM) infused into the left renal pelvis increased ipsilateral afferent renal nerve activity (110.0 ± 15.6% of basal value). Intravenous infusion of GLP-1 (1 µg·kg−1·min−1) for 30 min increased renal sympathetic nerve activity (RSNA). After the distal end of the renal nerve was cut to eliminate the afferent signal, the increase in efferent renal nerve activity during intravenous infusion of GLP-1 was diminished compared with the increase in total RSNA (17.0 ± 9.0% vs. 68.1 ± 20.0% of the basal value). Diuretic and natriuretic responses to intravenous infusion of GLP-1 were enhanced by total renal denervation (T-RDN) with acute surgical cutting of the renal nerves. Selective afferent renal nerve denervation (A-RDN) was performed by bilateral perivascular application of capsaicin on the renal nerves. Similar to T-RDN, A-RDN enhanced diuretic and natriuretic responses to GLP-1. Urine flow and Na+ excretion responses to GLP-1 were not significantly different between T-RDN and A-RDN groups. These results indicate that the diuretic and natriuretic effects of GLP-1 are partly governed via activation of afferent renal nerves by GLP-1 acting on sensory nerve fibers within the pelvis of the kidney.

2007 ◽  
Vol 293 (4) ◽  
pp. R1561-R1572 ◽  
Author(s):  
Ulla C. Kopp ◽  
Michael Z. Cicha ◽  
Lori A. Smith ◽  
Jan Mulder ◽  
Tomas Hökfelt

Increasing efferent renal sympathetic nerve activity (ERSNA) increases afferent renal nerve activity (ARNA). To test whether the ERSNA-induced increases in ARNA involved norepinephrine activating α-adrenoceptors on the renal sensory nerves, we examined the effects of renal pelvic administration of the α1- and α2-adrenoceptor antagonists prazosin and rauwolscine on the ARNA responses to reflex increases in ERSNA (placing the rat's tail in 49°C water) and renal pelvic perfusion with norepinephrine in anesthetized rats. Hot tail increased ERSNA and ARNA, 6,930 ± 900 and 4,870 ± 670%·s (area under the curve ARNA vs. time). Renal pelvic perfusion with norepinephrine increased ARNA 1,870 ± 210%·s. Immunohistochemical studies showed that the sympathetic and sensory nerves were closely related in the pelvic wall. Renal pelvic perfusion with prazosin blocked and rauwolscine enhanced the ARNA responses to reflex increases in ERSNA and norepinephrine. Studies in a denervated renal pelvic wall preparation showed that norepinephrine increased substance P release, from 8 ± 1 to 16 ± 1 pg/min, and PGE2 release, from 77 ± 11 to 161 ± 23 pg/min, suggesting a role for PGE2 in the norepinephrine-induced activation of renal sensory nerves. Prazosin and indomethacin reduced and rauwolscine enhanced the norepinephrine-induced increases in substance P and PGE2. PGE2 enhanced the norepinephrine-induced activation of renal sensory nerves by stimulation of EP4 receptors. Interaction between ERSNA and ARNA is modulated by norepinephrine, which increases and decreases the activation of the renal sensory nerves by stimulating α1- and α2-adrenoceptors, respectively, on the renal pelvic sensory nerve fibers. Norepinephrine-induced activation of the sensory nerves is dependent on renal pelvic synthesis/release of PGE2.


2018 ◽  
Vol 32 (S1) ◽  
Author(s):  
Kenichi Katsurada ◽  
Neeru M. Sharma ◽  
Hong Zheng ◽  
Xuefei Liu ◽  
Kaushik P. Patel

1992 ◽  
Vol 70 (5) ◽  
pp. 733-734 ◽  
Author(s):  
J. Michael Wyss

The kidney is the most highly innervated peripheral organ, and both the excretory and endocrine functions of the kidney are regulated by renal nerve activity. The kidney plays a dominant role in body fluid homeostasis, blood ionic concentration, and pH and thereby contributes importantly to systemic blood pressure control. Early studies suggested that the neural-renal interactions were responsible only for short-term adjustments in renal function, but more recent studies indicate that the renal nerves may be a major contributor to chronic renal defects leading to established hypertension and (or) renal disease. The neural-renal interaction is also of considerable interest as a model to elucidate the interplay between the nervous system and peripheral organs, since there is abundant anatomical and physiological information characterizing the renal nerves. The investigator has easy access to the renal nerves and the neural influence on renal function is directly quantifiable both in vivo and in vitro. In this symposium that was presented at the 1990 annual convention of the Society for Neuroscience in St. Louis, Missouri, three prominent researchers evaluate the most recent progress in understanding the interplay between the nervous system and the kidney and explore how the results of these studies relate to the broader questions concerning the nervous system's interactions.First, Luciano Barajas examines the detailed anatomy of the intrarenal distribution of the efferent and afferent renal nerves along the nephron and vasculature, and he evaluates the physiological role of each of the discrete components of the innervation. His basic science orientation combined with his deep appreciation of the clinical consequence of the failure of neural-renal regulation enhances his discussion of the anatomy. Ulla C. Kopp discusses the role of the renorenal reflex, which alters renal responses following stimulation of the contralateral kidney. She also considers her recent findings that efferent renal nerve activity can directly modify sensory feedback to the spinal cord from the kidney. Finally, J. Michael Wyss examines the functional consequences of neural control of the kidney in health and disease. Although the nervous system has often been considered as only an acute regulator of visceral function, current studies into hypertension and renal disease suggest that neural-renal dysfunction may be an important contributor to chronic diseases.Together, these presentations examine most of the recent advances in the area of neural-renal interactions and point out how these data form a basis for future research into neuronal interactions with all visceral organs. The relative simplicity of the neural-renal interaction makes this system an important model with which to elucidate all neural-peripheral and neural-neural interactions.


1980 ◽  
Vol 58 (5) ◽  
pp. 477-483 ◽  
Author(s):  
D. R. Wilson ◽  
M. Cusimano ◽  
U. Honrath

The role of the renal nerves in the altered sodium reabsorption which occurs during increased ureteral pressure was studied using clearance techniques in anaesthetized rats undergoing diuresis induced by isotonic saline infusion. In rats with a sham denervated kidney, an ipsilateral increase in ureteral pressure to 20 cm H2O resulted in a marked and significant decrease in sodium and water excretion, increased fractional sodium reabsorption, and increased urine osmolality with no significant change in glomerular filtration rate. A similar significant ipsilateral increase in tubular reabsorption of sodium occurred in rats with chronically denervated kidneys during increased ureteral pressure. The changes in tubular reabsorption were rapidly reversible after return of ureteral pressure to normal. These experiments indicate that enhanced tubular reabsorption of sodium during an ipsilateral increase in ureteral pressure is not mediated by increased renal nerve activity. During the antinatriuresis of increased ureteral pressure there was a decrease in the fractional reabsorption of sodium from the opposite normal kidney. The role of the renal nerves in this compensatory change in function in the opposite kidney was studied in two further groups of animals. The renal response to a contralateral increase in ureteral pressure was similar in denervated and sham-denervated kidneys. The results indicate that altered renal nerve activity, through ipsilateral or contralateral renorenal reflexes, is not responsible for the changes in tubular reabsorption of sodium which occur during increased ureteral pressure induced by partial ureteral obstruction.


1996 ◽  
Vol 271 (6) ◽  
pp. R1489-R1499 ◽  
Author(s):  
S. C. Malpas ◽  
A. Shweta ◽  
W. P. Anderson ◽  
G. A. Head

Changes in renal sympathetic nerve activity (SNA) are postulated to influence renal function in selective ways, such that different levels of activation produce particular renal responses, initially in renin release, then sodium excretion, with changes in renal hemodynamics occurring only with much greater stimulus intensities. The aim of this study was to determine the renal hemodynamic and excretory responses to graded physiological increases in renal SNA induced by breathing different hypoxic gas mixtures. Experiments were performed in seven conscious rabbits subjected to four gas mixtures (14% O2, 10% O2, 10% O2 + 3% CO2, and 10% O2 + 5% CO2) and instrumented for recording of renal nerve activity. After a 30-min control period, rabbits were subjected to one of the four gas mixtures for 30 min, and then room air was resumed for a further 30 min. The four gas mixtures increased renal SNA by 14, 38, 49, and 165% respectively, but arterial pressure (thus renal perfusion pressure) was not altered by any of the gas mixtures. The greatest level of sympathetic activation produced significant falls in glomerular filtration rate (GFR), renal blood flow, sodium and fluid excretion, and significant increases in plasma renin activity. These returned to levels not significantly different from control conditions in the 30-min period after the gas mixture. When the changes to the various gas mixtures were analyzed within each rabbit, a significant linear relationship was found with all variables to the increase in SNA. Renal denervation in a separate group of seven rabbits completely abolished all of the above responses to the different gas mixtures. Thus graded activation of renal nerves induced by changes in inspired gas mixtures resulted in graded decreases in renal blood flow, GFR, and sodium excretion and graded increases in renin activity, with the changes occurring across a similar range of nerve activities; there was no evidence for a selective change in any renal variable.


1992 ◽  
Vol 262 (5) ◽  
pp. R834-R841 ◽  
Author(s):  
N. G. Moss ◽  
A. B. Scoltock

Multiunit and single-unit recordings of afferent renal nerve activity (ARNA) were obtained in anesthetized spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats between 35 and 150 days of age. Intrapelvic backflow of urine at 20 mmHg excited ARNA at all ages in SHR (152 +/- 18% above control) and WKY rats (262 +/- 24%). In SHR, complete renal ischemia was more excitatory in rats older than 120 days (1,233 +/- 103%, n = 8) than in younger SHR (317 +/- 28%, n = 42). Single-unit recordings showed that this was related to the appearance of R1 chemoreceptors in older SHR and coincided with a decline in the proportion of R2 chemoreceptors in the renal nerves. Other chemoreceptive responses were identified in single units that did not show complete R1 or R2 characteristics, some of which showed responses consistent with a transformation process from R2 to R1 receptor type. R1 chemoreceptors were not present in WKY rats studied up to 150 days of age and, unlike SHR, the proportion of R2 chemoreceptors did not decline with age. Accordingly, complete renal ischemia in WKY rats caused a comparable excitation in multiunit ARNA at all ages (285 +/- 33%, n = 43). Oral enalapril from weaning to 100 days of age prevented hypertension in SHR but did not impair the responsiveness of ARNA to any stimulus. In WKY rats, enalapril treatment for the same period resulted in exaggerated ARNA response to renal ischemia (1,250 +/- 377% above control).(ABSTRACT TRUNCATED AT 250 WORDS)


1988 ◽  
Vol 254 (1) ◽  
pp. F32-F37 ◽  
Author(s):  
G. Szenasi ◽  
G. Kottra ◽  
P. Bencsath ◽  
L. Takacs

The effect of acute renal denervation (RD) on water (V), sodium (UNaV), and potassium excretion (UKV) from the hypertrophied and control kidney was studied in 5-sec-butyl-5-ethyl-2-thiobarbituric acid (Inactin)-anesthetized male rats 7 days after unilateral nephrectomy (Nx) or sham operation (SNx). V, UNaV, and UKV from the hypertrophied kidney were similar before and after RD or sham RD. In contrast, in SNx rats, left RD resulted in an ipsilateral increase in V (from 2.76 +/- 0.39 to 5.31 +/- 0.99 microliters.min-1.g-1), UNaV (from 109 +/- 36 to 857 +/- 331 nmol.min-1.g-1), and UKV (from 144 +/- 44 to 807 +/- 130 nmol.min-1.g-1; P less than 0.05 in all cases). Moreover, renal parameters from the hypertrophied kidney, subjected to either RD or sham RD, were not different from values after RD in SNx rats (V: Nx, sham RD = 5.72 +/- 1.10; Nx, RD = 5.23 +/- 0.66; SNx, RD = 5.31 +/- 0.99 microliters.min-1.g-1; UNaV: Nx, sham RD = 896 +/- 319; Nx, RD = 821 +/- 262; SNx, RD = 857 +/- 331 nmol.min-1.g-1; UKV: Nx, sham RD = 782 +/- 127; Nx, RD = 860 +/- 82; SNx, RD = 807 +/- 130 nmol.min-1.g-1). In additional experiments, integrated renal nerve activity (RNA) to the kidney in Nx and SNx rats was 4.0 +/- 0.3 and 10.7 +/- 0.9 microV (P less than 0.05), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)


1976 ◽  
Vol 51 (1) ◽  
pp. 93-102 ◽  
Author(s):  
E. J. Johns ◽  
Barbara A. Lewis ◽  
Bertha Singer

1. The effect of low-frequency stimulation of the renal nerves on renal function and renin release has been investigated. The experiments were performed in unilaterally nephrectomized, anaesthetized cats in which the nerves to the remaining kidney were sectioned. 2. When stimulation frequency was adjusted to reduce renal blood flow by approximately 15% for 15 min, glomerular filtration rate was hardly affected. The ratio sodium clearance/glomerular filtration rate was significantly reduced and plasma renin activity was significantly increased. 3. When the renal nerves were similarly stimulated in the presence of the β-adrenergic receptor blocking agent, propranolol, the glomerular filtration rate was significantly reduced and the rise in plasma renin activity was significantly inhibited. The reduction of sodium clearance/glomerular filtration rate was as great as in the control animals. 4. The results are consistent with the view that the maintenance of glomerular filtration rate, during renal nerve stimulation which reduced renal blood flow, may be mediated by the local generation of angiotensin. The results also suggest that angiotensin does not play an important role in the sodium retention associated with increased renal nerve activity.


1987 ◽  
Vol 253 (4) ◽  
pp. F767-F777 ◽  
Author(s):  
U. C. Kopp ◽  
L. A. Smith ◽  
G. F. DiBona

The effects of decreasing and increasing efferent renal nerve activity (ERNA) on the renorenal reflex responses to stimulation of renal mechanoreceptors (MR) (increased ureteral pressure) or renal chemoreceptors (CR) (retrograde ureteropelvic perfusion with 0.9 M NaCl) were examined in anesthetized rats. During prevailing ERNA, renal MR stimulation increased ipsilateral afferent renal nerve activity (ARNA) from 6 to 41 counts/s (spike counter) (n = 37) and from 2 to 6 resets/min, (voltage integrator) (n = 23), contralateral urine flow rate from 5.3 to 7.4 microliters . min-1 . g-1 (n = 38) and urinary sodium excretion from 0.7 to 1.1 mumol . min-1 . g-1 (n = 38) (all P less than 0.01), without affecting mean arterial pressure or contralateral glomerular filtration rate. Similar results were obtained with renal CR stimulation. Decreasing ERNA 74+/- 4% by hexamethonium, 10% body weight isotonic saline volume expansion, or inflation of a balloon at the junction of right atria and superior vena cava abolished the increase in ipsilateral ARNA and the contralateral diuresis and natriuresis produced by stimulation of renal MR or CR. Increasing ERNA 254+/- 120% (peak response, n = 15, P less than 0.01) by placing the rat's tail in 53 degrees C water increased basal ARNA 249+/- 80% (n = 6, P less than 0.05) and enhanced the ipsilateral ARNA response 202+/- 78% (n = 9, P less than 0.01) to renal MR stimulation. These results indicate that ERNA exerts a facilitatory effect on renal MR and CR and their afferent renal nerve fibers in the renorenal reflexes.


2020 ◽  
Vol 319 (5) ◽  
pp. F822-F832
Author(s):  
Kristina Rodionova ◽  
Roland Veelken ◽  
Karl F. Hilgers ◽  
Eva-Maria Paulus ◽  
Peter Linz ◽  
...  

Afferent renal nerves exhibit a dual function controlling central sympathetic outflow via afferent electrical activity and influencing intrarenal immunological processes by releasing peptides such as calcitonin gene-related peptide (CGRP). We tested the hypothesis that increased afferent and efferent renal nerve activity occur with augmented release of CGRP in anti-Thy1.1 nephritis, in which enhanced CGRP release exacerbates inflammation. Nephritis was induced in Sprague-Dawley rats by intravenous injection of OX-7 antibody (1.75 mg/kg), and animals were investigated neurophysiologically, electrophysiologically, and pathomorphologically 6 days later. Nephritic rats exhibited proteinuria (169.3 ± 10.2 mg/24 h) with increased efferent renal nerve activity (14.7 ± 0.9 bursts/s vs. control 11.5 ± 0.9 bursts/s, n = 11, P < 0.05). However, afferent renal nerve activity (in spikes/s) decreased in nephritis (8.0 ± 1.8 Hz vs. control 27.4 ± 4.1 Hz, n = 11, P < 0.05). In patch-clamp recordings, neurons with renal afferents from nephritic rats showed a lower frequency of high activity following electrical stimulation (43.4% vs. 66.4% in controls, P < 0.05). In vitro assays showed that renal tissue from nephritic rats exhibited increased CGRP release via spontaneous (14 ± 3 pg/mL vs. 6.8 ± 2.8 pg/ml in controls, n = 7, P < 0.05) and stimulated mechanisms. In nephritic animals, marked infiltration of macrophages in the interstitium (26 ± 4 cells/mm2) and glomeruli (3.7 ± 0.6 cells/glomerular cross-section) occurred. Pretreatment with the CGRP receptor antagonist CGRP8–37 reduced proteinuria, infiltration, and proliferation. In nephritic rats, it can be speculated that afferent renal nerves lose their ability to properly control efferent sympathetic nerve activity while influencing renal inflammation through increased CGRP release.


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