Anomalous renal vasculature

Toll-like receptors (TLRs) are now recognized as the major receptors for microbial pathogens on cells of the innate immune system. Recently, TLRs were also identified in many organs including the kidney. However, the cellular distribution and role of these renal TLRs remain largely unknown. In this paper, we investigated the expression of TLR4 in a cecal ligation and puncture (CLP) model of sepsis in Sprague-Dawley rats utilizing fluorescence microscopy. In sham animals, TLR4 was expressed predominantly in Tamm-Horsfall protein (THP)-positive tubules. In CLP animals, TLR4 expression increased markedly in all tubules (proximal and distal), glomeruli, and the renal vasculature. The staining showed a strong apical distribution in all tubules. A moderately less intense cellular signal colocalized partially with the Golgi apparatus. In addition, kidneys from septic rats showed increased expression of CD14 and THP. They each colocalized strongly with TLR4, albeit in different tubular segments. We also imaged the kidneys of live septic animals with two-photon microscopy after fluorescent lipopolysaccharide (LPS) injection. Within 10 min, LPS was seen at the brush border of some proximal tubules. Within 60 min, LPS was fully cytoplasmic in proximal tubules. Conversely, distal tubules showed no LPS uptake. We conclude that TLR4, CD14, and THP have specific renal cellular and tubular expression patterns that are markedly affected by sepsis. Systemic endotoxin can freely access the tubular and cellular sites where these proteins are present. Therefore, locally expressed TLRs and other interacting proteins could potentially modulate the renal response to systemic sepsis.

Download Full-text

Crosstalk relationship between adiponectin receptors, PPAR-γ and α-adrenoceptors in renal vasculature of diabetic WKYs

European Journal of Pharmacology ◽

10.1016/j.ejphar.2021.174703 ◽

2021 ◽

pp. 174703

Author(s):

Sheryar Afzal ◽

Munavvar Abdul Sattar ◽

Olorunfemi A. Eseyin ◽

Ali Attiq ◽

Edward James Johns

Keyword(s):

Adiponectin Receptors ◽

Renal Vasculature ◽

Ppar Γ

Download Full-text

Abstract 36: Deficiency in the Production of 20-HETE Contributes to Impaired Myogenic and TGF Responses in the Afferent Arteriole of Dahl S Rats

Hypertension ◽

10.1161/hyp.60.suppl_1.a36 ◽

2012 ◽

Vol 60 (suppl_1) ◽

Author(s):

Ying Ge ◽

Fan Fan ◽

Sydney R Murphy ◽

Jan Michael Williams ◽

Ruisheng Liu ◽

...

Keyword(s):

Renal Injury ◽

Tubuloglomerular Feedback ◽

Brown Norway ◽

Sodium Reabsorption ◽

Thick Ascending Limb ◽

Afferent Arteriole ◽

Synthesis Inhibitor ◽

Renal Vasculature ◽

Luminal Diameter ◽

Consomic Strain

Previous studies have indicated that a deficiency in the formation of 20-HETE in the proximal tubule and thick ascending limb of Henle in Dahl S rats increases sodium reabsorption and contributes to the development of hypertension. The present study examined whether the lack of 20-HETE production in the renal vasculature contributes to the progression of renal injury by altering the myogenic or tubuloglomerular feedback (TGF) response of the afferent arteriole (Af-Art). The production of 20-HETE was significantly lower by 54% in renal microvessels isolated from the kidneys of Dahl S rats versus that seen than in SS.5BN consomic strain in which chromosome 5 from the Brown Norway (BN) rat containing the CYP4A genes responsible for the formation of 20-HETE was transferred into the Dahl S genetic background. The luminal diameter of the Af-Art decreased by 14.7± 1.5% (from 20.5 ± 0.7 to 17.5 ± 0.8 μm, n=6) in SS.5BN rats whereas the diameter of the Af-Art remained unaltered in Dahl S rats (from 20.1 ± 0.6 to 21.7 ± 0.6 μm, n=7) when the perfusion pressure was increased from 60 mmHg to 120 mmHg. In other experiments, adenosine (1 μM) reduced the diameter of the Af-Art in the SS.5BN rats by 15±0.7% (from 20.1 ±0.4 to 17.1 ± 0.9 μm, n=3) whereas the Af-Art of Dahl S rats was unaltered. However, administration of a 20-HETE synthesis inhibitor, HET0016 (1 μM, n=6), or a selective 20-HETE antagonist, 6, 15-20-HEDE (10 μM, n=6) completely blocked the myogenic and adenosine responses in the Af-Art of SS.5BN rats but it had no effect in Dahl S rats. Administration of a 20-HETE agonist, 5, 14-20-HEDE (1 μM) restored the myogenic response (from 20.7 ± 0.7 to 17.6 ± 0.6 μm, n=7) and vasoconstrictor response to adenosine in the Af-Art of Dahl S rats. These studies confirm the key role of 20-HETE in modulating the responsiveness of the Af-Art and indicate that a deficiency in the formation of 20-HETE in renal microvessels contributes to the marked susceptibility of Dahl S rats to develop hypertension induced renal injury.

Download Full-text

Acute renal denervation produces a diuresis and natriuresis in young SHR but not WKY rats

AJP Renal Physiology ◽

10.1152/ajprenal.1986.251.4.f655 ◽

1986 ◽

Vol 251 (4) ◽

pp. F655-F661 ◽

Cited By ~ 3

Author(s):

M. A. Rudd ◽

R. S. Grippo ◽

W. J. Arendshorst

Keyword(s):

Sodium Excretion ◽

Renal Denervation ◽

Strain Differences ◽

Urine Flow ◽

Sprague Dawley ◽

Renal Vasculature ◽

Renal Nerve ◽

Water Excretion ◽

Spontaneously Hypertensive ◽

Wistar Kyoto

Clearance experiments were conducted to determine the effect of acute unilateral renal denervation (DNX) on renal hemodynamics and salt and water excretion in anesthetized 6-wk-old spontaneously hypertensive rats (SHR) and Wistar-Kyoto genetic control rats (WKY). Before DNX, SHR had higher mean arterial pressure (33%) and renal vascular resistance (RVR) (57%) and lower glomerular filtration rate (GFR) (10%); urine flow and sodium excretion were similar. Following DNX in SHR, sodium and water excretion increased by 138 and 62%, respectively (P less than 0.001); GFR and RVR were unchanged. In contrast, DNX in WKY did not affect urine flow (0%) or sodium excretion (-21%). These strain differences were observed in Okamoto-Aoki rats from two sources. Effective DNX was indicated by 95% reduction of norepinephrine content 3 days after DNX in both strains. Six-week-old Sprague-Dawley and Munich-Wistar rats, in contrast to WKY, responded to DNX with a natriuresis (+182%) and diuresis (+95%) (P less than 0.001). Renal function was unaffected by sham DNX in SHR. Our results indicate that efferent renal nerve activity has little tonic influence on the renal vasculature in these young rats. Augmented neurotransmitter release and/or tubular responsiveness may be involved in fluid and electrolyte retention and the pathogenesis of hypertension in SHR. Conversely, blunted renal neuroeffector responses may prevent WKY from developing hypertension.

Download Full-text

Does endoplasmic reticulum stress mediate endothelin-1-induced renal inflammation?

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00184.2013 ◽

2013 ◽

Vol 305 (2) ◽

pp. R107-R109 ◽

Cited By ~ 8

Author(s):

Carmen De Miguel ◽

Jennifer S. Pollock

Keyword(s):

Endoplasmic Reticulum ◽

Thick Ascending Limb ◽

Afferent Arteriole ◽

Renal Vasculature ◽

Renal Inflammation ◽

Endothelin 1 ◽

Collecting Ducts ◽

Potent Vasoconstrictor ◽

Eventual Death ◽

Vasoconstrictor Peptide

Endothelin-1 (ET-1) is the most potent vasoconstrictor peptide known. It exerts its actions through two pharmacologically different receptors: ETA and ETB receptors. In the renal vasculature, there is a majority of ETB receptors in the efferent arteriole, whereas a greater amount of ETA receptors are located in the afferent arteriole. The nephron is rich in ETB receptors, especially in the thick ascending limb and collecting ducts, while containing a smaller amount of ETA receptors. High levels of circulating or renal ET-1 have been described in cardiovascular diseases such as hypertension or diabetes, diseases also associated to renal inflammation. Despite extensive evidence associating high levels of ET-1 to increased renal inflammation, the molecular mechanism(s) by which ET-1 leads to renal immune infiltration and/or immune activation remains unknown. In this minireview, we propose that the ET-1/ETA pathway mediates an increase in renal endoplasmic reticulum (ER) stress, initially a survival mechanism that if prolonged, leads to the eventual death of the cell via apoptosis.

Download Full-text

RENAL VASCULATURE AND HIGH DOSE FENTANYL

Anesthesiology ◽

10.1097/00000542-198209001-00032 ◽

1982 ◽

Vol 57 (3) ◽

pp. A32-A32 ◽

Cited By ~ 3

Author(s):

L. L. Priano

Keyword(s):

High Dose ◽

Renal Vasculature

Download Full-text

Ca-dependent hemodynamic and natriuretic effects of atrial extract in isolated rat kidney

AJP Renal Physiology ◽

10.1152/ajprenal.1984.246.4.f447 ◽

1984 ◽

Vol 246 (4) ◽

pp. F447-F456 ◽

Cited By ~ 9

Author(s):

M. J. Camargo ◽

H. D. Kleinert ◽

S. A. Atlas ◽

J. E. Sealey ◽

J. H. Laragh ◽

...

Keyword(s):

Perfusion Pressure ◽

Rat Kidney ◽

Fractional Excretion ◽

Electrolyte Excretion ◽

Renal Vasculature ◽

Filtration Fraction ◽

Perfused Rat Kidney ◽

Site Of Action ◽

Initial Control ◽

Renal Vascular

The effects of rat atrial tissue extract on renal hemodynamics and fluid and electrolyte excretion were investigated in the isolated perfused rat kidney (IK). IK were perfused at a constant effective perfusion pressure of about 90 mmHg. After control clearance periods (C), extracts of rat atria (AE) or ventricles (VE) were added to the perfusate and three 10-min experimental periods followed. AE, but not VE, significantly increased (P less than 0.001) renal vascular resistance (RVR) to 133 +/- 8% of C, GFR to 201 +/- 34%, filtration fraction to 245 +/- 41%, urine flow (V) to 675 +/- 131%, fractional excretion (FE) of H2O to 336 +/- 29%, absolute Na excretion (UNaV) to 1,259 +/- 290%, FENa to 642 +/- 129%, UKV to 2,226 +/- 1,237%, and FEK to 542 +/- 119%. Despite the marked natriuresis, since GFR doubled, Na reabsorption rose from 78.3 +/- 36.3 in C to 132 +/- 36.3 mueq/min after AE. The effects of AE were immediate and lasted to the end of the perfusion. The lower the initial control GFR, the larger was the AE-induced increase in GFR. Perfusion with low [Ca] (0.2 mM) or verapamil (10(-5) M) severely blunted the hemodynamic, diuretic, kaliuretic, and natriuretic effects of AE. AE decreased rather than increased the RVR when IK were perfused with vasoconstrictors such as angiotensin II, norepinephrine, or vasopressin. The results demonstrate that AE acts directly on the kidney, eliciting powerful Ca-dependent hemodynamic and natriuretic responses. The natriuresis induced by AE can be accounted for, at least in part, by its renal hemodynamic effects rather than by the presence of a putative tubular natriuretic factor. The hypothesis is advanced that AE contains a substance(s) which behaves as a functional agonist/antagonist of endogenous vasoconstrictors with a preferential site of action on the efferent arterioles of the renal vasculature.

Download Full-text

LIVE RENAL DONORS

The Professional Medical Journal ◽

10.29309/tpmj/2010.17.02.2352 ◽

2010 ◽

Vol 17 (02) ◽

pp. 241-245

Author(s):

HAFIZ SHAHZAD ASHRAF ◽

Shafique Ahmed ◽

IMRAN HYDER ◽

Mubashir Ijaz ◽

MOHAMMAD USMAN KHAN

Keyword(s):

Ct Angiography ◽

Kidney Diseases ◽

Imaging Modality ◽

Helical Computed Tomography ◽

Medical Institute ◽

Renal Vasculature ◽

Conventional Angiography ◽

Ct Angiogram ◽

Operative Findings ◽

Collecting System

Objectives: To compare the findings of helical computed tomographic angiography and intra-operative findings in live related donors. To evaluate the accuracy of helical computed tomography with advanced 3D techniques in depicting the renal vasculature, parenchymal and anatomy of collecting system. Setting: Sheikh Zayed Post Graduate Medical Institute and National Institute of kidney diseases Lahore. Material and Method: Between June 2006 to May 2009 eighty potential donors underwent CT angiogram as a part of theirpreoperative workup. We retrospectively studied the CT angiogram and compared the finding with the surgical findings. The results were reviewed with radiologists to determine the discrepancy in discordant cases. Results: The accuracy of CT angiography was 93.40% to predict number of vessels. Five arteries and one vein was missed, this disconcordant comprised 7.59% during initial CT interpretation. The overallconcordance between CT angiography and operative findings in delineating the arterial anatomy was found in 74(93.67%) and venous in 78 (98.73%) donors. All CT scans demonstrated normal collecting system except one, which showed a dilated right pelvicalical system and ureter. Simple renal cysts about the size of 2-4 cm were found in the four left kidneys. CT scan supplied additional important anatomical informationincluding kidney size and the presence of nephrolithiasis. Conclusion: Helical CT angiography is very specific for arterial and venous anatomy as well as other anatomical and functional details. It provides all the information required by a surgeon. It can become the single imaging modality for preoperative assessment of potential donors in place of conventional angiography and intravenous urography. CT angiography isminimally invasive and cost effective.

Download Full-text