scholarly journals Effects of combined carotid chemoreceptor and atrial receptor stimulation on renal blood flow in anaesthetized dogs.

1983 ◽  
Vol 336 (1) ◽  
pp. 91-100
Author(s):  
C T Kappagoda ◽  
F Karim ◽  
D Mackay
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Receptor Stimulation ◽  
Atrial Receptor

scholarly journals P2X1 receptor blockade inhibits whole kidney autoregulation of renal blood flow in vivo

2010 ◽  
Vol 298 (6) ◽  
pp. F1360-F1368 ◽  
Author(s):  
David A. Osmond ◽  
Edward W. Inscho
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Renal Perfusion ◽  
Receptor Activation ◽  
Receptor Blockade ◽  
Sprague Dawley ◽  
Receptor Stimulation ◽  
Kidney Blood Flow

In vitro experiments demonstrate that P2X1 receptor activation is important for normal afferent arteriolar autoregulatory behavior, but direct in vivo evidence for this relationship occurring in the whole kidney is unavailable. Experiments were performed to test the hypothesis that P2X1 receptors are important for autoregulation of whole kidney blood flow. Renal blood flow (RBF) was measured in anesthetized male Sprague-Dawley rats before and during P2 receptor blockade with PPADS, P2X1 receptor blockade with IP5I, or A1 receptor blockade with DPCPX. Both P2X1 and A1 receptor stimulation with α,β-methylene ATP and CPA, respectively, caused dose-dependent decreases in RBF. Administration of either PPADS or IP5I significantly blocked P2X1 receptor stimulation. Likewise, administration of DPCPX significantly blocked A1 receptor activation to CPA. Autoregulatory behavior was assessed by measuring RBF responses to reductions in renal perfusion pressure. In vehicle-infused rats, as pressure was decreased from 120 to 100 mmHg, there was no decrease in RBF. However, in either PPADS- or IP5I-infused rats, each decrease in pressure resulted in a significant decrease in RBF, demonstrating loss of autoregulatory ability. In DPCPX-infused rats, reductions in pressure did not cause significant reductions in RBF over the pressure range of 100–120 mmHg, but the autoregulatory curve tended to be steeper than vehicle-infused rats over the range of 80–100 mmHg, suggesting that A1 receptors may influence RBF at lower pressures. These findings are consistent with in vitro data from afferent arterioles and support the hypothesis that P2X1 receptor activation is important for whole kidney autoregulation in vivo.

Determination of renal blood flow by thermodilution method

1978 ◽  
Vol 38 (5) ◽  
pp. 495-499 ◽  
Author(s):  
Torbjörn Leivestad ◽  
Erling Brodwall ◽  
Svein Simonsen
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Thermodilution Method

Measurement of Renal Blood Flow by 131I-Labelled Sodium Iodohippurate Imaging in a Rat Model of Herpes Encephalitis

1990 ◽  
Vol 31 (5) ◽  
pp. 538-539
Author(s):  
G. M. Cleator ◽  
P. E. Klapper ◽  
A. G. Lewis ◽  
H. L. Sharma ◽  
A. M. Smith
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Rat Model ◽  
Herpes Encephalitis

Bias and Precision in Magnetic Resonance Imaging‐Based Estimates of Renal Blood Flow: Assessment by Triangulation

2021 ◽  
Author(s):  
Bashair A. Alhummiany ◽  
David Shelley ◽  
Margaret Saysell ◽  
Maria‐Alexandra Olaru ◽  
Bernd Kühn ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Blood Flow ◽  
Magnetic Resonance ◽  
Renal Blood Flow ◽  
Resonance Imaging

Renal blood flow, early distal sodium, and plasma renin concentrations during osmotic diuresis

2000 ◽  
Vol 279 (4) ◽  
pp. R1268-R1276 ◽  
Author(s):  
Paul P. Leyssac ◽  
Niels-Henrik Holstein-Rathlou ◽  
Ole Skøtt
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Sodium Excretion ◽  
Plasma Renin ◽  
Urine Flow ◽  
Sodium Reabsorption ◽  
Osmotic Diuresis ◽  
Nacl Concentration ◽  
Proximal Tubular ◽  
Distal Tubules

Inconsistencies in previous reports regarding changes in early distal NaCl concentration (EDNaCl) and renin secretion during osmotic diuresis motivated our reinvestigation. After intravenous infusion of 10% mannitol, EDNaCl fell from 42.6 to 34.2 mM. Proximal tubular pressure increased by 12.6 mmHg. Urine flow increased 10-fold, and sodium excretion increased by 177%. Plasma renin concentration (PRC) increased by 58%. Renal blood flow and glomerular filtration rate decreased, however end-proximal flow remained unchanged. After a similar volume of hypotonic glucose (152 mM), EDNaClincreased by 3.6 mM, ( P < 0.01) without changes in renal hemodynamics, urine flow, sodium excretion rate, or PRC. Infusion of 300 μmol NaCl in a smaller volume caused EDNaCl to increase by 6.4 mM without significant changes in PRC. Urine flow and sodium excretion increased significantly. There was a significant inverse relationship between superficial nephron EDNaCl and PRC. We conclude that EDNa decreases during osmotic diuresis, suggesting that the increase in PRC was mediated by the macula densa. The results suggest that the natriuresis during osmotic diuresis is a result of impaired sodium reabsorption in distal tubules and collecting ducts.

Effect of acetylcholine infusion on adrenal vasculature and catecholamine secretion

1993 ◽  
Vol 265 (3) ◽  
pp. H966-H972 ◽  
Author(s):  
J. R. Tobin ◽  
M. J. Breslow ◽  
R. J. Traystman
Keyword(s):  
Blood Flow ◽  
Muscarinic Receptor ◽  
Cholinergic Receptor ◽  
Catecholamine Secretion ◽  
Receptor Stimulation ◽  
Similar Dose ◽  
Adrenal Vasculature ◽  
Higher Doses

To evaluate effects of cholinergic receptor stimulation on regional adrenal blood flow (Q, radiolabeled microspheres) and catecholamine secretion, acetylcholine (ACh) was infused into pentobarbital-anesthetized, ventilated dogs. Unilateral adrenal denervation and placement of lumboadrenal catheters preceded intra-aortic infusion of 1) ACh alone (n = 6), 2) ACh plus hexamethonium (Hex) 20 mg/kg (n = 6), or 3) ACh plus atropine (Atr) (0.5 mg/kg) and Hex. ACh alone and in combination with Hex elicited similar dose-related (2, 20, and 100 mumol/min) increases in catecholamine secretion (181 +/- 61 to 1,055 +/- 229, 31,644 +/- 9,411, and 179,181 +/- 69,659 ng.min-1 x g medulla-1), whereas Hex and Atr together inhibited ACh-induced secretion by 95%. ACh caused marked medullary vasodilation (0.71 +/- 0.05 to 0.14 +/- 0.03 mmHg.ml-1 x min.100 g) in all three groups. To determine whether medullary vasodilation was due to incomplete muscarinic blockade, Hex-pretreated animals (n = 4) received ACh (100 mumol/min) and three increasing doses of Atr (0.5, 5, and 25 mg/kg). Catecholamine secretion was inhibited by all doses of Atr; however, vasodilation was blocked only by the two higher doses of Atr. These data suggest possible different mechanisms of muscarinic receptor-mediated catecholamine secretion and vasodilation.

Dopamine-1 receptor stimulation impairs intestinal oxygen utilization during critical hypoperfusion

2003 ◽  
Vol 284 (2) ◽  
pp. H668-H675 ◽  
Author(s):  
Jorge A. Guzman ◽  
Ariosto E. Rosado ◽  
James A. Kruse
Keyword(s):  
Blood Flow ◽  
Mucosal Blood Flow ◽  
Control Group ◽  
Oxygen Utilization ◽  
Hemorrhage Control ◽  
Receptor Stimulation ◽  
Anesthetized Dogs ◽  
Group 2 ◽  
Increased Susceptibility ◽  
Group 1

Effects of a dopamine-1 (DA-1) receptor agonist on systemic and intestinal oxygen delivery (D˙o 2)-uptake relationships were studied in anesthetized dogs during sequential hemorrhage. Control ( group 1) and experimental animals ( group 2) were treated similarly except for the addition of fenoldopam (1.0 μg · kg−1 · min−1) in group 2. Both groups had comparable systemic criticalD˙o 2(D˙o 2crit), but animals in group 2 had a higher gut D˙o 2crit(1.12 ± 1.13 vs. 0.80 ± 0.09 ml · kg−1 · min−1, P < 0.05). At the mucosal level, a clear biphasic delivery-uptake relationship was not observed in group 1; thus oxygen consumption by the mucosa may be supply dependent under physiological conditions. Group 2 demonstrated higher peak mucosal blood flow and lack of supply dependency at higher mucosalD˙o 2 levels. Fenoldopam resulted in a more conspicuous biphasic relationship at the mucosa and a rightward shift of overall splanchnic D˙o 2crit despite increased splanchnic blood flow. These findings suggest that DA-1 receptor stimulation results in increased gut perfusion heterogeneity and maldistribution of perfusion, resulting in increased susceptibility to ischemia.

scholarly journals Extraction Methods for the Determination of Regional Renal Blood Flow

1979 ◽  
Vol 84 (2) ◽  
pp. 163-171 ◽  
Author(s):  
A.-C. Ericson ◽  
M. Sjöquist ◽  
H. R. Ulfendahl
Keyword(s):  
Blood Flow ◽  
Renal Blood Flow ◽  
Extraction Methods ◽  
Regional Renal Blood Flow
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