Reflex effects on components of synchronized renal sympathetic nerve activity

1998 ◽  
Vol 275 (3) ◽  
pp. F441-F446 ◽  
Author(s):  
Gerald F. DiBona ◽  
Susan Y. Jones
Keyword(s):  
Sympathetic Nerve ◽  
Peak Frequency ◽  
Peak Height ◽  
Nerve Fibers ◽  
Receptor Stimulation ◽  
Renal Nerve ◽  
Renal Sympathetic Nerve Activity ◽  
Renal Sympathetic Nerve ◽  
Baroreceptor Stimulation ◽  
Renal Sympathetic

The effects of peripheral thermal receptor stimulation (tail in hot water, n = 8, anesthetized) and cardiac baroreceptor stimulation (volume loading, n = 8, conscious) on components of synchronized renal sympathetic nerve activity (RSNA) were examined in rats. The peak height and peak frequency of synchronized RSNA were determined. The renal sympathoexcitatory response to peripheral thermal receptor stimulation was associated with an increase in the peak height. The renal sympathoinhibitory response to cardiac baroreceptor stimulation was associated with a decrease in the peak height. Although heart rate was significantly increased with peripheral thermal receptor stimulation and significantly decreased with cardiac baroreceptor stimulation, peak frequency was unchanged. As peak height reflects the number of active fibers, reflex increases and decreases in synchronized RSNA are mediated by parallel increases and decreases in the number of active renal nerve fibers rather than changes in the centrally based rhythm or peak frequency. The increase in the number of active renal nerve fibers produced by peripheral thermal receptor stimulation reflects the engagement of a unique group of silent renal sympathetic nerve fibers with a characteristic response pattern to stimulation of arterial baroreceptors, peripheral and central chemoreceptors, and peripheral thermal receptors.

scholarly journals Renal hemodynamic effects of activation of specific renal sympathetic nerve fiber groups

1999 ◽  
Vol 276 (2) ◽  
pp. R539-R549 ◽  
Author(s):  
Gerald F. DiBona ◽  
Linda L. Sawin
Keyword(s):  
Sympathetic Nerve ◽  
Nerve Fibers ◽  
External Heat ◽  
Renal Vasculature ◽  
Receptor Stimulation ◽  
Response Characteristics ◽  
Renal Sympathetic Nerve ◽  
Sympathetic Nerve Fibers ◽  
Vasoconstrictor Response ◽  
Renal Sympathetic

To examine the effect of activation of a unique population of renal sympathetic nerve fibers on renal blood flow (RBF) dynamics, anesthetized rats were instrumented with a renal sympathetic nerve activity (RSNA) recording electrode and an electromagnetic flow probe on the ipsilateral renal artery. Peripheral thermal receptor stimulation (external heat) was used to activate a unique population of renal sympathetic nerve fibers and to increase total RSNA. Total RSNA was reflexly increased to the same degree with somatic receptor stimulation (tail compression). Arterial pressure and heart rate were increased by both stimuli. Total RSNA was increased to the same degree by both stimuli but external heat produced a greater renal vasoconstrictor response than tail compression. Whereas both stimuli increased spectral density power of RSNA at both cardiac and respiratory frequencies, modulation of RBF variability by fluctuations of RSNA was small at these frequencies, with values for the normalized transfer gain being ∼0.1 at >0.5 Hz. During tail compression coherent oscillations of RSNA and RBF were found at 0.3–0.4 Hz with normalized transfer gain of 0.33 ± 0.02. During external heat coherent oscillations of RSNA and RBF were found at both 0.2 and 0.3–0.4 Hz with normalized transfer gains of 0.63 ± 0.05 at 0.2 Hz and 0.53 ± 0.04 to 0.36 ± 0.02 at 0.3–0.4 Hz. Renal denervation eliminated the oscillations in RBF at both 0.2 and 0.3–0.4 Hz. These findings indicate that despite similar increases in total RSNA, external heat results in a greater renal vasoconstrictor response than tail compression due to the activation of a unique population of renal sympathetic nerve fibers with different frequency-response characteristics of the renal vasculature.

Partial renal ischemia elicits heterogeneous control of renal sympathetic nerve activity to ischemic and nonischemic regions of the kidney

2006 ◽  
Vol 290 (2) ◽  
pp. R322-R330 ◽  
Author(s):  
Kiyoshi Shimizu ◽  
Kanji Matsukawa ◽  
Jun Murata ◽  
Hirotsugu Tsuchimochi ◽  
Ishio Ninomiya
Keyword(s):  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Renal Ischemia ◽  
Nerve Activity ◽  
Renal Nerve ◽  
Renal Sympathetic Nerve Activity ◽  
Renal Sympathetic Nerve ◽  
Ischemic Region ◽  
Nerve Bundles ◽  
Renal Sympathetic

We tested the hypothesis that renal sympathetic nerve activity (RSNA) to the ischemic and nonischemic regions responded differently during partial ischemia of the kidney in pentobarbital-anesthetized cats. The renal artery divides into two branches at the front of the renal hilus: one branch perfuses predominantly the dorsal half of the kidney, and the other perfuses its ventral half. We identified the innervated area of a renal nerve bundle by supramaximal electrical stimulation and subsequently determined the changes in RSNA in response to occlusion of either renal arterial branch for 3 min. RSNA to the nonischemic region of the kidney gradually decreased by 23 ± 4% during partial renal ischemia, whereas RSNA to the ischemic region of the same kidney showed no significant change. Crushing either all renal nerve bundles or only the renal nerve bundles terminated to the ischemic region abolished the decrease in RSNA to the nonischemic region. Furthermore, intra-arterial administration of a prostaglandin synthesis inhibitor (meclofenamate, 4 mg/kg) abolished the decrease in RSNA to the nonischemic region of the kidney. Following spinal transection at the level of T7, the inhibitory response in RSNA to the nonischemic region disappeared, whereas the RSNA to the ischemic region was markedly augmented by 47 ± 17%. Thus it is likely that renal chemoreceptors activated during renal partial ischemia elicit heterogeneous control of renal sympathetic outflows to the ischemic and nonischemic regions of the same kidney, which may be determined by a net output between the supraspinal inhibitory and spinal excitatory reflexes.

Increased renal nerve activity in cardiac failure: arterial vs. cardiac baroreflex impairment

1995 ◽  
Vol 268 (1) ◽  
pp. R112-R116 ◽  
Author(s):  
G. F. DiBona ◽  
L. L. Sawin
Keyword(s):  
Normal Control ◽  
Cardiac Failure ◽  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Baroreceptor Reflex ◽  
Nerve Activity ◽  
Renal Nerve ◽  
Renal Sympathetic Nerve Activity ◽  
Renal Sympathetic Nerve ◽  
Renal Sympathetic

Cardiac failure is characterized by increased renal sympathetic nerve activity that is associated with an impairment of both arterial and cardiac baroreceptor reflex function. These reflex dysfunctions are in the afferent limb at the level of the peripheral baroreceptors. This study sought to define the relative quantitative magnitude of the defects in arterial and cardiac baroreceptor function in cardiac failure. Renal sympathetic nerve activity was measured in anesthetized normal control rats and rats with cardiac failure (left coronary ligation) during sequential random order sinoaortic denervation and vagotomy to interrupt afferent input from the arterial and cardiac baroreceptors, respectively. Increases in renal sympathetic nerve activity after individual or combined sinoaortic denervation and vagotomy were less (P < 0.05 for both) in cardiac failure than in normal control rats in both order sequences (42 +/- 5 vs. 87 +/- 8%; 44 +/- 5 vs. 108 +/- 7%). In cardiac failure rats, vagotomy produced lesser increases (P < 0.05 for both) in renal sympathetic nerve activity than sinoaortic denervation in both order sequences (10 +/- 4 vs. 32 +/- 5%; 13 +/- 2 vs. 30 +/- 5%). The relative magnitude of impaired cardiac baroreceptor reflex function that is associated with the increased renal sympathetic nerve activity of cardiac failure is greater than that of impaired arterial baroreceptor reflex function.

Renal neurohormonal and vascular responses to dynamic exercise in humans

1991 ◽  
Vol 70 (5) ◽  
pp. 2279-2286 ◽  
Author(s):  
B. Tidgren ◽  
P. Hjemdahl ◽  
E. Theodorsson ◽  
J. Nussberger
Keyword(s):  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Plasma Concentrations ◽  
Dynamic Exercise ◽  
Ang Ii ◽  
Nerve Activity ◽  
Renal Nerve ◽  
Renal Sympathetic Nerve Activity ◽  
Renal Sympathetic Nerve ◽  
Renal Sympathetic

Effects of graded supine dynamic exercise (30, 60, and 80-90% of maximal physical capacity, i.e., work loads of 69, 132, and 188 W) on renal vascular resistance (RVR); renal sympathetic nerve activity [assessed by the renal venous overflow of norepinephrine (NE)]; renal overflows of dopamine (DA), immunoreactive neuropeptide Y (NPY-LI), and renin; as well as plasma concentrations of angiotensin-(1-8)-octapeptide (ANG II) were evaluated in eight healthy male volunteers. Exercise evoked stimulus-dependent and marked elevations of RVR, arterial NE, epinephrine (Epi), and DA. RVR increased by 140% and the renal overflows of NE and DA increased by 1,331 and 179%, respectively, at 188 W. A net removal of NPY-LI at rest turned into a small net renal overflow, which correlated with increases in RVR at 188 W. Increases in renin release (+1,200% at 188 W) correlated with increases in renal NE and DA overflows and with arterial Epi levels. Arterial ANG II levels increased stimulus dependently (by 264% at 188 W) and correlated more closely with increases in RVR than did other variables. Thus dynamic exercise is a potent stimulus for renal nerve activation in humans, and renal sympathetic nerve activity may contribute to increased RVR both directly (NE and, at exhaustive work loads, possibly NPY) and indirectly (via renin-mediated ANG II formation).

Effects of l-carnosine on renal sympathetic nerve activity and DOCA-salt hypertension in rats

2002 ◽  
Vol 97 (2) ◽  
pp. 99-102 ◽  
Author(s):  
Akira Niijima ◽  
Tomoko Okui ◽  
Yasuo Matsumura ◽  
Toshihiko Yamano ◽  
Nobuo Tsuruoka ◽  
...  
Keyword(s):  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Nerve Activity ◽  
Renal Sympathetic Nerve Activity ◽  
Renal Sympathetic Nerve ◽  
Salt Hypertension ◽  
Renal Sympathetic

Suppression of renal sympathetic nerve activity during portal vein infusion of hypertonic saline

1998 ◽  
Vol 274 (1) ◽  
pp. R97-R103 ◽  
Author(s):  
Yasuhiro Nishida ◽  
Isao Sugimoto ◽  
Hironobu Morita ◽  
Hiroshi Murakami ◽  
Hiroshi Hosomi ◽  
...  
Keyword(s):  
Portal Vein ◽  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Area Postrema ◽  
Nerve Activity ◽  
Renal Sympathetic Nerve Activity ◽  
Renal Sympathetic Nerve ◽  
Venous Infusion ◽  
Portal Vein Infusion ◽  
Renal Sympathetic

Sodium ions absorbed from the intestine are postulated to act on the liver to reflexly suppress renal sympathetic nerve activity (RSNA), resulting in inhibition of sodium reabsorption in the kidney. To test the hypothesis that the renal sympathoinhibitory response to portal venous NaCl infusion involves an action of arginine vasopressin (AVP) at the area postrema, we examined the effects of portal venous infusion of hypertonic NaCl on RSNA before and after lesioning of the area postrema (APL) or after pretreatment with an AVP V1 receptor antagonist (AVPX). Rabbits were chronically instrumented with portal and femoral venous catheters, femoral arterial catheters, and renal nerve electrodes. Portal venous infusion of 9.0% NaCl (0.02, 0.05, 0.10, and 0.15 ml ⋅ kg−1 ⋅ min−1of 9.0% NaCl for 10 min) produced a dose-dependent suppression of RSNA (−12 ± 3, −34 ± 3, −62 ± 5, and 80 ± 2%, respectively) that was greater than that produced by femoral vein infusion of 9.0% NaCl (2 ± 3, −3 ± 2, −12 ± 4, and −33 ± 3%, respectively). The suppression of RSNA produced by portal vein infusion of 9.0% NaCl was partially reversed by pretreatment with AVPX (−9 ± 3, −20 ± 3, −41 ± 4, and −55 ± 4%, respectively) and by APL (−11 ± 2, −25 ± 2, −49 ± 3, and −59 ± 6%, respectively). There were no significant differences between the effects of AVPX and APL, and the effect of APL was not augmented by AVPX. These results indicate that the suppression of RSNA due to portal venous infusion of 9.0% NaCl involves an action of AVP via the area postrema.

scholarly journals Electroacupuncture and Moxibustion Decrease Renal Sympathetic Nerve Activity and Retard Progression of Renal Disease in Rats

2012 ◽  
Vol 35 (5) ◽  
pp. 355-364 ◽  
Author(s):  
Josne C. Paterno ◽  
Cássia T. Bergamaschi ◽  
Ruy R. Campos ◽  
Elisa M.S. Higa ◽  
Maria Fernanda Soares ◽  
...  
Keyword(s):  
Renal Disease ◽  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Nerve Activity ◽  
Renal Sympathetic Nerve Activity ◽  
Renal Sympathetic Nerve ◽  
Progression Of Renal Disease ◽  
Renal Sympathetic
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