Supersensitivity to norepinephrine in chronically denervated kidneys: evidence for a postsynaptic effect

1987 ◽  
Vol 65 (11) ◽  
pp. 2219-2224 ◽  
Author(s):  
J. Krayacich ◽  
R. L. Kline ◽  
P. F. Mercer

Denervation supersensitivity in chronically denervated kidneys increases renal responsiveness to increased plasma levels of norepinephrine. To determine whether this effect is caused by presynaptic (i.e., loss of uptake) or postsynaptic changes, we studied the effect of continuous infusion of norepinephrine (330 ng/min, i.v.) and methoxamine (4 μg/min, i.v.), an α1 adrenergic agonist that is not taken up by nerve terminals, on renal function of innervated and denervated kidneys. Ganglionic blockade was used to eliminate reflex adjustments in the innervated kidney and mean arterial pressure was maintained at preganglionic blockade levels by an infusion of arginine vasopressin. With renal perfusion pressure controlled there was a significantly greater decrease in renal blood flow (−67 ± 9 vs. −33 ± 8%), glomerular filtration rate (−60 ± 9 vs. −7 ± 20%), urine flow (−61 ± 7 vs. −24 ± 11%), sodium excretion (−51 ± 15 vs. −32 ± 21%), and fractional excretion of sodium (−50 ± 9 vs. −25 ± 15%) from the denervated kidneys compared with the innervated kidneys during the infusion of norepinephrine. During the infusion of methoxamine there was a significantly greater decrease from the denervated compared with the innervated kidneys in renal blood flow (−54 ± 10 vs. −30 ± 14%), glomerular filtration rate (−51 ± 11 vs. −19 ± 17%), urine flow (−55 ± 10 vs. −39 ± 10%), sodium excretion (−70 ± 9 vs. −59 ± 11%), and fractional excretion of sodium (−53 ± 10 vs. −41 ± 10%). These results suggest that vascular and tubular supersensitivity to norepinephrine in chronically denervated kidneys is due to postsynaptic changes involving α1-adrenergic receptors.

1962 ◽  
Vol 202 (5) ◽  
pp. 893-896 ◽  
Author(s):  
Jimmy B. Langston ◽  
Arthur C. Guyton ◽  
James H. DePoyster ◽  
George G. Armstrong

The experiments of this study show that intravenous infusion of norepinephrine has a direct effect on the kidneys of areflex dogs to cause a decrease in renal blood flow, glomerular filtration rate, and urinary output. However, when the infusion rate is below an average of 0.0006 mg/kg/min, the renal blood flow, glomerular filtration rate, and urinary output increase as a result of an increase in arterial pressure which accompanies the infusion of norepinephrine. Above this infusion rate, the direct effect of the norepinephrine on the kidneys is greater than the effect of the rising arterial pressure, thus causing the blood flow, glomerular filtration rate, and urinary output to decrease. The results from this study indicate that changes in renal arterial pressure result in very significant changes in renal blood flow, glomerular filtration rate, and urinary output in spite of the local autoregulation of renal blood flow.


1978 ◽  
Vol 55 (4) ◽  
pp. 335-339 ◽  
Author(s):  
A. L. Riley ◽  
T. C. Hagen ◽  
J. E. Stefaniak

1. The effect of infusion of ovine prolactin was studied in anaesthetized dogs pretreated with bromocryptine to reduce the release of endogenous prolactin. 2. Prolactin, injected intravenously and also directly into one kidney, resulted in a 12–18% increase in glomerular filtration rate (GFR) by both kidneys. 3. This increased GFR was not associated with any demonstrable changes in whole-kidney blood flow, distribution of intrarenal blood flow, fractional excretion of sodium or osmolar or free-water clearance. 4. We conclude that ovine prolactin produced an increase in GFR not dependent on an increase in whole-kidney plasma flow.


1990 ◽  
Vol 78 (2) ◽  
pp. 165-168 ◽  
Author(s):  
Paolo Madeddu ◽  
Nicola Glorioso ◽  
Aldo Soro ◽  
Paolo Manunta ◽  
Chiara Troffa ◽  
...  

1. To evaluate whether sodium intake can modulate the action of endogenous kinins on renal function and haemodynamics, a receptor antagonist of bradykinin was infused in conscious normotensive rats maintained on either a normal or a low sodium diet. 2. The antagonist inhibited the hypotensive effect of exogenously administered bradykinin. It did not change the vasodepressor effect of acetylcholine, dopamine or prostaglandin E2. 3. The antagonist did not affect mean blood pressure, glomerular filtration rate, renal blood flow or urinary sodium excretion, in rats on sodium restriction. It did not change mean blood pressure, glomerular filtration rate or urinary sodium excretion, but decreased renal blood flow, in rats on a normal sodium intake. 4. The kallikrein–kinin system has a role in the regulation of renal blood flow in rats on a normal sodium diet.


1980 ◽  
Vol 238 (4) ◽  
pp. F279-F282 ◽  
Author(s):  
J. C. Burnett ◽  
F. G. Knox

Studies were performed on anesthetized dogs to determine the relationship of interstitial pressure to sodium excretion during renal vein constriction in the presence and absence of volume expansion. Renal interstitial pressure was measured from implanted capsules during basal renal venous pressure and increased pressures of 10, 20, 30, and 40 mmHg. A positive relationship between renal venous pressure and interstitial pressure was demonstrated in hydropenia and in volume expansion, with markedly higher interstitial pressures obtained in volume expansion. A positive correlation was demonstrated between fractional sodium excretion and renal interstitial pressure in hydropenia as compared to a significant negative correlation in volume expansion. Negative correlations were demonstrated in volume expansion between renal interstitial pressure and glomerular filtration rate and renal blood flow as compared to no significant change in these parameters in hydropenia. Accordingly, a positive correlation was demonstrated between renal interstitial pressure and sodium excretion in hydropenia but not in volume expansion. Volume expansion was characterized by higher interstitial pressure and decreased sodium excretion in association with decreased renal blood flow and glomerular filtration rate.


1993 ◽  
Vol 264 (1) ◽  
pp. F79-F87 ◽  
Author(s):  
D. S. Majid ◽  
A. Williams ◽  
L. G. Navar

Inhibition of nitric oxide (NO) synthesis by intrarenal administration of nitro-L-arginine (NLA) leads to decreases in urinary sodium excretion (UNaV) in association with the increases in renal vascular resistance (RVR). In the present study, we examined the ability of the kidney to alter its sodium excretion in response to acute changes in renal arterial pressure (RAP) in anesthetized dogs before and during intrarenal infusion of NLA (50 micrograms.kg-1.min-1). NO synthesis inhibition in 11 dogs increased RVR by 32 +/- 4% and decreased renal blood flow (RBF) by 25 +/- 3%, outer cortical blood flow by 25 +/- 6%, urine flow by 37 +/- 14%, UNaV by 71 +/- 5%, and fractional excretion of sodium (FENa) by 71 +/- 4%. Glomerular filtration rate was not significantly changed during NLA infusion. As previously reported, there was suppression of the RBF autoregulation plateau during NO synthesis inhibition. In addition, there was a marked attenuation of urine flow and UNaV responses to reductions in RAP (150 to 75 mmHg), with significant reductions in the slopes of the relationships between RAP vs. UNaV and RAP vs. FENa during NLA infusion. Similar responses were observed in nine other dogs treated with the angiotensin receptor antagonist losartan, indicating that an augmented activity of the renin-angiotensin system is not responsible for attenuation of the slope of the pressure-natriuresis relationship during NLA infusion. These data suggest that NO may participate in the mediation of the pressure-natriuresis response.


1988 ◽  
Vol 74 (1) ◽  
pp. 63-69 ◽  
Author(s):  
S. B. Harrap ◽  
A. E. Doyle

1. To determine the relevance of renal circulatory abnormalities found in the immature spontaneously hypertensive rat (SHR) to the genetic hypertensive process, glomerular filtration rate and renal blood flow were measured in conscious F2 rats, derived from crossbreeding SHR and normotensive Wistar–Kyoto rats (WKY), at 4, 11 and 16 weeks of age by determining the renal clearances of 51Cr-ethylenediaminetetra-acetate and 125I-hippuran respectively. Plasma renin activity was measured at 11 and 16 weeks of age. 2. Mean arterial pressure, glomerular filtration rate and renal blood flow increased between 4 and 11 weeks of age. Between 11 and 16 weeks the mean glomerular filtration rate and renal blood flow did not alter, although the mean arterial pressure rose significantly. At 11 weeks of age, during the developmental phase of hypertension, a significant negative correlation between mean arterial pressure and both glomerular filtration rate and renal blood flow was noted. However, by 16 weeks when the manifestations of genetic hypertension were more fully expressed, no correlation between mean arterial pressure and renal blood flow or glomerular filtration rate was observed. Plasma renin activity was negatively correlated with both glomerular filtration rate and renal blood flow, but the relationship was stronger at 11 than at 16 weeks of age. 3. These results suggest that the reduction in renal blood flow and glomerular filtration rate, found in immature SHR, is genetically linked to the hypertension and may be of primary pathogenetic importance. It is proposed that the increased renal vascular resistance in these young animals stimulates the rise of systemic arterial pressure which returns renal blood flow and glomerular filtration rate to normal.


2018 ◽  
Vol 46 (6) ◽  
pp. e560-e566 ◽  
Author(s):  
Jenny Skytte Larsson ◽  
Vitus Krumbholz ◽  
Anders Enskog ◽  
Gudrun Bragadottir ◽  
Bengt Redfors ◽  
...  

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