scholarly journals Endothelin mediates renal vascular memory of a transient rise in perfusion pressure due to NOS inhibition

1999 ◽  
Vol 276 (4) ◽  
pp. F629-F634 ◽  
Author(s):  
Xin-Zhou Zhang ◽  
Chris Baylis
Keyword(s):  
Perfusion Pressure ◽  
Left Kidney ◽  
Renal Perfusion ◽  
Transient Increase ◽  
Transient Rise ◽  
Group 3 ◽  
Group 2 ◽  
The Right ◽  
Renal Vascular ◽  
Renal Responses

We investigated the renal responses to NO synthase (NOS) inhibition with N-monomethyl-l-arginine (l-NMA; 30 mg/kg) in anesthetized rats in which renal perfusion pressure (RPP) to the left kidney was mechanically adjusted. Acutel-NMA increased blood pressure (BP, ∼20%) and renal vascular resistance (RVR) rose (∼50%) in the right kidneys that were always exposed to high RPP. In group 1, the left kidney was exposed to a transient increase (5 min) in RPP which was then normalized, and the rise in RVR was similar to the right kidney. In group 2 the left kidney was never exposed to high RPP, and the rise in RVR was attenuated relative to the right kidney. In group 3, rats were pretreated with the endothelin (ET) receptor antagonist Bosentan, immediately before exposure of the left kidney to a transient increase in RPP, and the rise in RVR was also attenuated relative to the right kidney. NOS inhibition resulted in a natriuresis and diuresis in the right kidneys, and ∼50% of the natriuresis persisted in the left kidney of group 2, in the absence of any rise in RPP. ET antagonism completely prevented the natriuresis and diuresis in response to acutel-NMA in both left and right kidneys. These data suggest that transient exposure to high RPP by NOS inhibition prevents an appropriate vasodilatory response when RPP is lowered, due to the intrarenal action of ET.

scholarly journals Renal Perfusion Pressure Determines Infiltration of Leukocytes in the Kidney of Rats With Angiotensin II–Induced Hypertension

Hypertension ◽  
2020 ◽  
Vol 76 (3) ◽  
pp. 849-858 ◽  
Author(s):  
Satoshi Shimada ◽  
Justine M. Abais-Battad ◽  
Ammar J. Alsheikh ◽  
Chun Yang ◽  
Megan Stumpf ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Perfusion Pressure ◽  
Left Kidney ◽  
Renal Perfusion ◽  
Leukocyte Infiltration ◽  
Ang Ii ◽  
Dietary Salt ◽  
Renal Perfusion Pressure ◽  
Induced Hypertension ◽  
The Right

The present study examined the extent to which leukocyte infiltration into the kidneys in Ang II (angiotensin II)-induced hypertension is determined by elevation of renal perfusion pressure (RPP). Male Sprague-Dawley rats were instrumented with carotid and femoral arterial catheters for continuous monitoring of blood pressure and a femoral venous catheter for infusion. An inflatable aortic occluder cuff placed between the renal arteries with computer-driven servo-controller maintained RPP to the left kidney at control levels during 7 days of intravenous Ang II (50 ng/kg per minute) or vehicle (saline) infusion. Rats were fed a 0.4% NaCl diet throughout the study. Ang II–infused rats exhibited nearly a 50 mm Hg increase of RPP (carotid catheter) to the right kidney while RPP to the left kidney (femoral catheter) was controlled at baseline pressure throughout the study. As determined at the end of the studies by flow cytometry, right kidneys exhibited significantly greater numbers of T cells, B cells, and monocytes/macrophages compared with the servo-controlled left kidneys and compared with vehicle treated rats. No difference was found between Ang II servo-controlled left kidneys and vehicle treated kidneys. Immunostaining found that the density of glomeruli, cortical, and outer medullary capillaries were significantly reduced in the right kidney of Ang II–infused rats compared with servo-controlled left kidney. We conclude that in this model of hypertension the elevation of RPP, not Ang II nor dietary salt, leads to leukocyte infiltration in the kidney and to capillary rarefaction.

scholarly journals A tissue-engineered urinary conduit in a porcine urinary diversion model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Arkadiusz Jundziłł ◽  
Piotr Kwieciński ◽  
Daria Balcerczyk ◽  
Tomasz Kloskowski ◽  
Dariusz Grzanka ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Urinary Diversion ◽  
Porcine Model ◽  
Histological Evaluation ◽  
Metabolic Complications ◽  
Group 3 ◽  
Group 2 ◽  
The Right ◽  
Group 1

AbstractThe use of an ileal segment is a standard method for urinary diversion after radical cystectomy. Unfortunately, utilization of this method can lead to numerous surgical and metabolic complications. This study aimed to assess the tissue-engineered artificial conduit for urinary diversion in a porcine model. Tissue-engineered tubular polypropylene mesh scaffolds were used for the right ureter incontinent urostomy model. Eighteen male pigs were divided into three equal groups: Group 1 (control ureterocutaneostomy), Group 2 (the right ureter-artificial conduit-skin anastomoses), and Group 3 (4 weeks before urostomy reconstruction, the artificial conduit was implanted between abdomen muscles). Follow-up was 6 months. Computed tomography, ultrasound examination, and pyelogram were used to confirm the patency of created diversions. Morphological and histological analyses were used to evaluate the tissue-engineered urinary diversion. All animals survived the experimental procedures and follow-up. The longest average patency was observed in the 3rd Group (15.8 weeks) compared to the 2nd Group (10 weeks) and the 1st Group (5.8 weeks). The implant’s remnants created a retroperitoneal post-inflammation tunnel confirmed by computed tomography and histological evaluation, which constitutes urostomy. The simultaneous urinary diversion using a tissue-engineered scaffold connected directly with the skin is inappropriate for clinical application.

scholarly journals Preemptive analgesic effect of lidocaine in a chronic neuropathic pain model

2009 ◽  
Vol 67 (4) ◽  
pp. 1088-1092 ◽  
Author(s):  
Leonardo M. Batista ◽  
Igor M. Batista ◽  
João P. Almeida ◽  
Carlos H. Carvalho ◽  
Samuel B. de Castro-Costa ◽  
...  
Keyword(s):  
Neuropathic Pain ◽  
Sciatic Nerve ◽  
Control Group ◽  
Thermal Stimulus ◽  
Lidocaine Group ◽  
Local Infiltration ◽  
Neuropathic Pain Model ◽  
Group 3 ◽  
Group 2 ◽  
The Right

Preemptive analgesia inhibits the progression of pain caused by surgical lesions. To analyze the effect of lidocaine on postoperative pain relief, we performed compression of the right sciatic nerve in Wistar rats and observed the differences on behavior between the group that received lidocaine and the group that was not treated with the local anesthetics pre-operatively. Group 1 was not operated (control); group 2 underwent the sciatic nerve ligature without lidocaine; group 3, underwent surgery with previous local infiltration of lidocaine. Group 2 showed significantly longer scratching times with a peak on day 14 post-operative (p=0.0005) and reduction in the latency to both noxious (p=0.003) and non-noxious (p=0.004) thermal stimulus. Group 3 presented significantly shorter scratching times (p=0.004) and longer latency times when compared to Group 2. Preemptive use of lidocaine 2% can potentially reduce the postoperative neuropathic pain associated with sciatic nerve compression.

scholarly journals Transcriptomic analysis reveals inflammatory and metabolic pathways that are regulated by renal perfusion pressure in the outer medulla of Dahl-S rats

2018 ◽  
Vol 50 (6) ◽  
pp. 440-447 ◽  
Author(s):  
Louise C. Evans ◽  
Alex Dayton ◽  
Chun Yang ◽  
Pengyuan Liu ◽  
Theresa Kurth ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Perfusion Pressure ◽  
Left Kidney ◽  
Respiratory Control ◽  
Renal Perfusion ◽  
Renal Physiology ◽  
Sequencing Analysis ◽  
Functional Changes ◽  
Renal Perfusion Pressure ◽  
Novel Approach

Studies exploring the development of hypertension have traditionally been unable to distinguish which of the observed changes are underlying causes from those that are a consequence of elevated blood pressure. In this study, a custom-designed servo-control system was utilized to precisely control renal perfusion pressure to the left kidney continuously during the development of hypertension in Dahl salt-sensitive rats. In this way, we maintained the left kidney at control blood pressure while the right kidney was exposed to hypertensive pressures. As each kidney was exposed to the same circulating factors, differences between them represent changes induced by pressure alone. RNA sequencing analysis identified 1,613 differently expressed genes affected by renal perfusion pressure. Three pathway analysis methods were applied, one a novel approach incorporating arterial pressure as an input variable allowing a more direct connection between the expression of genes and pressure. The statistical analysis proposed several novel pathways by which pressure affects renal physiology. We confirmed the effects of pressure on p-Jnk regulation, in which the hypertensive medullas show increased p-Jnk/Jnk ratios relative to the left (0.79 ± 0.11 vs. 0.53 ± 0.10, P < 0.01, n = 8). We also confirmed pathway predictions of mitochondrial function, in which the respiratory control ratio of hypertensive vs. control mitochondria are significantly reduced (7.9 ± 1.2 vs. 10.4 ± 1.8, P < 0.01, n = 6) and metabolomic profile, in which 14 metabolites differed significantly between hypertensive and control medullas ( P < 0.05, n = 5). These findings demonstrate that subtle differences in the transcriptome can be used to predict functional changes of the kidney as a consequence of pressure elevation.

Plasma renin activity responses to graded decreases in renal perfusion pressure in fetal and newborn lambs

1992 ◽  
Vol 262 (3) ◽  
pp. R524-R529 ◽  
Author(s):  
N. D. Binder ◽  
D. F. Anderson
Keyword(s):  
Blood Pressure ◽  
Plasma Renin Activity ◽  
Perfusion Pressure ◽  
Plasma Renin ◽  
Renal Perfusion ◽  
Renin Activity ◽  
Renal Perfusion Pressure ◽  
Arterial Blood ◽  
The Right ◽  
The Relationship

We examined the relationship between acute reductions in renal perfusion pressure, as approximated by femoral arterial blood pressure, and plasma renin activity in the uninephrectomized fetal lamb. Renal perfusion pressure was reduced and maintained at a constant value by controlled partial occlusion of the aorta above the renal artery. After 15 min of reduced blood pressure, blood samples were taken for determination of plasma renin activity. This protocol was performed 22 times in 11 fetal lambs. Additionally, three of the fetuses were delivered by cesarean section and studied as newborns for the first week of life. In the fetus, there was a linear relationship between log plasma renin activity and femoral arterial blood pressure (P less than 0.01). After birth, the relationship still existed, although it was shifted to the right (P less than 0.0001). We conclude that there is a significant relationship between plasma renin activity and renal perfusion pressure in the fetal lamb, and as early as 1 day after birth, this relationship shifts to the right in the newborn lamb.

Effects of ATP on pre- and postglomerular juxtamedullary microvasculature

1992 ◽  
Vol 263 (5) ◽  
pp. F886-F893 ◽  
Author(s):  
E. W. Inscho ◽  
K. Ohishi ◽  
L. G. Navar
Keyword(s):  
Perfusion Pressure ◽  
Renal Perfusion ◽  
Renal Perfusion Pressure ◽  
Organ Systems ◽  
Smooth Muscle Function ◽  
Juxtamedullary Nephron ◽  
Afferent Arterioles ◽  
The Right ◽  
Dose Dependent

Based on evidence that extracellular ATP can influence vascular smooth muscle function in other organ systems, experiments were conducted to characterize the responsiveness of rat juxtamedullary microvascular segments to ATP. Experiments were performed using the in vitro blood-perfused juxtamedullary nephron preparation combined with video microscopy. Pentobarbital-anesthetized rats were pretreated with enalaprilat (2 mg iv) for 30 min before the right kidney was isolated and prepared for study. Renal perfusion pressure was set at 110 mmHg and held constant. Under control conditions, afferent and efferent arteriolar diameters averaged 19.9 +/- 1.4 (n = 19) and 21.6 +/- 1.2 microns (n = 10), respectively. Superfusion with 1, 10, and 100 microM ATP solutions induced sustained dose-dependent afferent vasoconstriction of 8.3 +/- 1.4, 12.8 +/- 1.7, and 12.1 +/- 2.1%, respectively (P < 0.01). Afferent vasoconstrictor responses to ATP were also observed during adenosine receptor blockade. In contrast, efferent arterioles were unresponsive to ATP stimulation even at concentrations as high as 100 microM (P > 0.05). Arcuate and interlobular arterial diameters averaged 82.0 +/- 15.7 (n = 5) and 43.4 +/- 4.5 microns (n = 6), respectively, during control conditions and responded to ATP treatment with a transient vasoconstriction followed by a gradual return to control diameter. Interlobular arteries exhibited a sustained constriction only at the 100 microM concentration (P < 0.05). These data demonstrate that afferent arterioles are more responsive to ATP treatment than other renal microvascular segments and suggest the presence of ATP-sensitive P2x purinoceptors on pre- but not postglomerular juxtamedullary microvascular elements.

Unilateral renal ischaemia in the rat: Effect of method of occlusion of the blood supply on function of ipsilateral and contralateral kidneys

1987 ◽  
Vol 73 (1) ◽  
pp. 11-17 ◽  
Author(s):  
O. S. Ferwana ◽  
S. C. Pirie
Keyword(s):  
Renal Artery ◽  
Blood Supply ◽  
Left Kidney ◽  
Severe Damage ◽  
Flow Rates ◽  
Renal Ischaemia ◽  
Group 3 ◽  
Group 2 ◽  
Renal Hilus ◽  
Group 1

1. The functions of right and left kidneys were measured immediately preceding, during and for 4 h after 45 min occlusion of the blood supply to the left kidney. 2. The blood supply was occluded by placing a clamp around the renal artery near to the aorta (group 1), near to the renal hilus (group 2) or by clamping the renal pedicle after prior separation of the kidney from perirenal tissue (group 3). 3. During ischaemia right kidneys had increased urine flow rates and excretion of sodium and water, but inulin clearances (CIn) remained unchanged. 4. After ischaemia left kidneys were isosthenuric with depressed CIn. 5. Occlusion of the renal artery alone resulted in non-oliguric kidneys in which CIn was reduced to 10% and 1% respectively for groups 1 and 2. 6. The most severe damage to function was seen in the kidneys of group 3 which were oliguric and in which CIn was depressed to 0.1% of the pre-ischaemic value. 7. It is concluded that the pedicle clamp method produced complete renal ischaemia and the most severe damage to function. Occlusion of the renal artery produced incomplete ischaemia and a less severe fall in function which depended upon the site of occlusion.

Effect of aortic clamping on proximal reabsorption and sodium excretion in the rat

1977 ◽  
Vol 232 (2) ◽  
pp. F92-F96 ◽  
Author(s):  
R. W. Osgood ◽  
N. H. Lameire ◽  
M. I. Sorkin ◽  
J. H. Stein
Keyword(s):  
Sodium Excretion ◽  
Perfusion Pressure ◽  
Left Kidney ◽  
Extracellular Volume ◽  
Extracellular Fluid ◽  
Renal Perfusion ◽  
Ringer Solution ◽  
Aortic Clamping ◽  
Group I ◽  
Before And After

It has been suggested that aortic clamping prior to expansion of the extracellular fluid volume prevents the natriuretic response normally seen in this setting. To further evaluate this finding, two groups of re-collection micropuncture studies were performed before and after 7.5% body wt expansion with Ringer solution. Group I, immediate-clamp studies, n, 11. After control collections, perfusion pressure to the left kidney was decreased to 75 mmHg followed by Ringer loading. Group II, delayed-clamp studies, n, 8. After control collections, Ringer solution was given for 40 min. Then the left renal perfusion pressure was reduced to 75 mmHg and the Ringer infusion was continued at the same rate. In the immediate-clamp group, there was no change in total kidney glomerular filtration rate (GFR) (1.16 vs. 1.11 ml/min), nephron GFR (40 vs. 39 nl/min), tubular fluid-to-plasma inulin ratio (2.40 vs. 2.28), or filtrate delivery out of the proximal tubule (18 vs. 18 ndium excretion were not significantly altered. In the delayed-clamp studies, there was also no change in total or nephron GFR, but the tubular fluid-to-plasma inulin ratio fell from 2.52 to 1.65 (P less than .001) and distal delivery rose 9 nl/min after expansion (P less than .001). Sodium excretion increased 3.83 mueq/min and fractional sodium excretion rose 2.28%, both values being markedly greater than in the immediate-clamp studies (P less than .005 for both). These results demonstrate that immediate clamping obviates the fall in proximal reabsorption and the natriuretic response to Ringer loading and suggests that intrarenal adjustments are a major determinant of the magnitude of the natriuretic response to expansion of the extracellular volume

Effects of renal perfusion pressure on the natriuresis induced by atrial natriuretic factor

1987 ◽  
Vol 253 (2) ◽  
pp. F234-F238
Author(s):  
A. A. Seymour ◽  
S. G. Smith ◽  
E. K. Mazack
Keyword(s):  
Vascular Resistance ◽  
Atrial Natriuretic Factor ◽  
Perfusion Pressure ◽  
Renal Perfusion ◽  
Renal Vascular Resistance ◽  
Base Line ◽  
Renal Perfusion Pressure ◽  
Natriuretic Factor ◽  
Renal Vascular ◽  
Atrial Natriuretic

Synthetic atrial natriuretic factor (ANF 101-126) was infused at 1, 5, 25, and 125 pmol X kg-1 X min-1 into the renal artery of anesthetized, one-kidney dogs. During administration of 25 and 125 pmol X kg-1 X min-1 of ANF 101-126, fractional sodium excretion (FENa) rose from 1.4 +/- 0.3 to 6.6 +/- 1.1 and 5.6 +/- 1.3% when renal perfusion pressure (RPP) was at its basal level (112 +/- 5 mmHg). When base-line RPP was lowered to 101 +/- 5 mmHg by tightening a suprarenal aortic constriction, the same doses raised FENa to only 5.6 +/- 1.6 and 5.1 +/- 1.6%. A larger reduction of beginning RPP to 82 +/- 4 mmHg suppressed the natriuretic responses to 25 and 125 pmol X kg-1 X min-1 of ANF 101-126 to only 1.4 +/- 0.8 and 0.8 +/- 0.3%, respectively.During the peak natriuretic dose of 25 pmol X kg-1 X min-1, renal vascular resistance (RVR) fell from 0.88 +/- 0.10 to 0.68 +/- 0.07, from 0.78 +/- 0.10 to 0.68 +/- 0.12, and from 0.60 +/- 0.06 to 0.61 +/- 0.06 mmHg X ml-1 X min-1 at RPP = RPP = 112, 101, and 82 mmHg, respectively. ANF 101-126 did not affect glomerular filtration rate (GFR) at any level of RPP tested. In conclusion, the natriuretic responses to ANF 101-126 occurred without changes in GFR and were modulated by the prevailing levels of renal perfusion pressure and renal vascular resistance.

A Comparison of Arterial and Venous Flaps

1992 ◽  
Vol 17 (3) ◽  
pp. 359-364 ◽  
Author(s):  
S. P. CHOW ◽  
D. Z. CHEN ◽  
Y. D. GU
Keyword(s):  
Survival Rate ◽  
Elastic Properties ◽  
Perfusion Pressure ◽  
Skin Flap ◽  
Sprague Dawley ◽  
Venous Flaps ◽  
Sprague Dawley Rats ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

The survival rate and elastic properties of the anterior abdominal skin flap in Sprague-Dawley rats were studied in three groups of animals. In group 1 where the flaps were supplied by a normal artery, arterial flaps (1A) had better survival rate and elastic properties than venous flaps (1B). In group 2, where the flaps were supplied by an artery with diminished perfusion pressure, the arterial flaps (2A) still had slightly better results than venous flaps (2B). However, in group 3 where the flaps were supplied by a vein, venous flaps (3B) had better results than arterial flaps (3A).

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