Renal expression and urinary excretion of aquaporin-2 in postobstructive uropathy in rats

2021 ◽  
pp. 1-8
Author(s):  
Anabel Brandoni ◽  
Adriana M. Torres
Keyword(s):  
Time Course ◽  
Renal Cortex ◽  
Renal Medulla ◽  
Obstructive Nephropathy ◽  
Kidney Cortex ◽  
Mrna Levels ◽  
Whole Cell Lysate ◽  
Aquaporin 2 ◽  
Immunohistochemical Techniques ◽  
Apical Membranes

This work assessed the time course of water renal management together with aquaporin-2 (AQP2) kidney expression and urinary AQP2 levels (AQP2u) in obstructive nephropathy. Adult male Wistar rats were monitored after 1, 2, and 7 days of bilateral ureteral release (bilateral ureteral obstruction (BUO); BUO-1, BUO-2 and BUO-7). Renal water handling was evaluated using conventional clearance techniques. AQP2 levels were assessed by immunoblotting and immunohistochemical techniques. AQP2 expression in apical membranes was downregulated in BUO-1 rats and upregulated both in BUO-2 and BUO-7 animals. AQP2 protein expression in whole cell lysate fraction from kidney cortex and medulla were significantly decreased in all the experimental groups. Concomitantly, mRNA levels of AQP2 decreased in renal medulla of all groups and in renal cortex from BUO-1; however, in renal cortex from BUO-2 and BUO-7 a recovery and an increase in the level of AQP2 mRNA were, respectively, observed. BUO-7 group showed a significant increase in AQP2u. The alterations observed in apical membranes AQP2 expression could explain, at least in part, the evolution time of water kidney management in the postobstructive phase of BUO. Additionally, the AQP2u increase after 7 days of ureteral release may be postulated as a biomarker of improvement in the kidney function.

Gene expression of growth-related proteins and ECM constituents in response to unilateral nephrectomy

1992 ◽  
Vol 262 (3) ◽  
pp. F389-F396 ◽  
Author(s):  
T. Nakamura ◽  
I. Ebihara ◽  
Y. Tomino ◽  
H. Koide ◽  
K. Kikuchi ◽  
...  
Keyword(s):  
Time Course ◽  
Renal Cortex ◽  
Core Protein ◽  
Control Level ◽  
Unilateral Nephrectomy ◽  
Nuclear Antigen ◽  
Type Iii Collagen ◽  
Type I ◽  
Mrna Levels ◽  
Related Proteins

To identify the specific regulatory mechanism associated with the events following unilateral nephrectomy, we measured the levels of mRNA encoding for extracellular matrix (ECM) constituents, for protooncogenes, and for proliferating cell nuclear antigen (PCNA) in renal cortex and glomeruli. One hour after left nephrectomy, c-jun and c-fos mRNA levels in renal cortex increased rapidly and then decreased rapidly to the control level, whereas c-myc and PCNA mRNA levels showed a slower and more sustained increase, with a peak at 6 h after nephrectomy, and then decreased to the control level after 7 days. mRNA levels for basement membrane components including alpha 1-chain of type IV collagen, laminin B1 and B2 chains, and heparan sulfate proteoglycan core protein were significantly increased in renal cortex at 12 h after nephrectomy, whereas those for interstitial collagens including alpha 1-chains of type I and type III collagen were unchanged following nephrectomy. On the other hand, the glomerular expression of all genes examined in this study showed little change during the experimental period. These results suggest that the time course of mRNA expression of ECM constituents is different from that of growth-related proteins in renal cortex and that glomerular mRNA levels for these components may not be associated with renal hypertrophy in the early stages following unilateral nephrectomy.

Time course of renal glutamate dehydrogenase induction during NH4Cl loading in rats

1992 ◽  
Vol 262 (6) ◽  
pp. F999-F1006 ◽  
Author(s):  
P. A. Wright ◽  
R. K. Packer ◽  
A. Garcia-Perez ◽  
M. A. Knepper
Keyword(s):  
Glutamate Dehydrogenase ◽  
Time Course ◽  
Renal Cortex ◽  
Ammonium Excretion ◽  
Mrna Levels ◽  
Outer Medulla ◽  
Acid Intake ◽  
Blood Ph ◽  
Outer Stripe ◽  
Acid Loading

To study mechanisms involved in renal glutamate dehydrogenase (GDH) regulation in response to systemic acid loading, we have measured blood pH, ammonium excretion, renal GDH mRNA levels, and GDH activity in rats. Acid intake (0.28 M NH4Cl in drinking water for 3 days) increased GDH mRNA levels in the renal cortex, but had no effect in the outer stripe of the outer medulla, inner stripe of the outer medulla, or the inner medulla. Rats were subjected to a step change in acid intake by alkali loading for 3 days (7.2 meq NaHCO3 per day in food slurry) and shifting to acid loading for up to 7 days (7.2 meq NH4Cl in food slurry). Ammonium excretion rose rapidly, increasing by 14-fold in the first 24-h period and 38-fold in the second 24-h period. Cortical GDH mRNA levels were increased relative to alkali-loaded values by 3.7-fold in 24 h, 4.3-fold in 4 days, but only 2.2-fold in 7 days. GDH activity was unchanged after 24 h of acid intake, but was significantly increased after 48 h. We concluded the following: 1) GDH mRNA is present in all regions of the kidney, but levels increase in response to acid loading only in the renal cortex; 2) GDH mRNA levels increase within 1 day after the initiation of acid loading, but the associated increase in functional enzyme activity takes 2 or more days; and 3) the large increases in ammonium excretion that occur in the first day after initiation of acid loading are not dependent on increased GDH activity.

Presence and distribution of endothelin-1 gene expression in human kidney

1994 ◽  
Vol 267 (4) ◽  
pp. F679-F687 ◽  
Author(s):  
C. Pupilli ◽  
M. Brunori ◽  
N. Misciglia ◽  
C. Selli ◽  
L. Ianni ◽  
...  
Keyword(s):  
Gene Expression ◽  
Endothelial Cells ◽  
In Situ Hybridization ◽  
Renal Cortex ◽  
Cdna Probe ◽  
Renal Medulla ◽  
Human Kidney ◽  
Renal Tumors ◽  
Mrna Levels

To investigate the presence and the distribution of preproendothelin-1 (prepro-ET-1) mRNA in human kidney, eight human kidneys obtained at surgery from patients affected by localized renal tumors were studied. Northern blot analysis using a human prepro-ET-1 cDNA probe labeled with 32P showed the presence of a single band of approximately 2.3 kb that was present both in the renal cortex and medulla of all the kidneys studied. Densitometric analysis of hybridization signals demonstrated that prepro-ET-1 mRNA levels in the renal medulla were 2.2-fold higher than those in the renal cortex. The distribution of prepro-ET-1 mRNA in human kidney was investigated by in situ hybridization using a human prepro-ET-1 RNA probe labeled with 35S. The greatest density of prepro-ET-1 mRNA was observed in the renal medulla, where hybridization signal was demonstrated in vasa recta bundles and capillaries and in collecting ducts. By combining in situ hybridization with immunohistochemical detection of von Willebrand factor, we demonstrated that 93 +/- 2.5% of nontubular medullary cells containing prepro-ET-1 mRNA were endothelial cells. In the cortex, prepro-ET-1 mRNA was localized in the endothelial layer of arcuate and interlobular arteries and veins and in the endothelial cells of afferent arterioles. The results of the present study demonstrate that ET-1 gene expression is present in vascular and tubular structures of the human kidney. It is possible that ET-1 synthesized locally in the human kidney represents a local system affecting renal hemodynamics and functions through paracrine and/or autocrine actions on different renal structures.

Changes in NOS activity and protein expression during acute and prolonged ANG II administration

2002 ◽  
Vol 282 (1) ◽  
pp. R31-R37 ◽  
Author(s):  
Carol Moreno ◽  
Almudena López ◽  
María T. Llinás ◽  
Francisca Rodríguez ◽  
Antonio López-Farré ◽  
...  
Keyword(s):  
Left Ventricle ◽  
Protein Expression ◽  
Time Course ◽  
Renal Cortex ◽  
Renal Medulla ◽  
Mesenteric Arteries ◽  
Ang Ii ◽  
Protein Levels ◽  
Renal Changes ◽  
Phenylephrine Infusion

The aim of this study was to assess the effects of acute or prolonged increases of ANG II on nitric oxide synthase (NOS) activities and protein expression in mesenteric resistance vessels, left ventricle, renal cortex, and renal medulla. The response of NOS activities to ANG II is compared with that induced by phenylephrine. ANG II or phenylephrine were infused over either 3 h or 3 days to conscious rats. NOS activity was examined by measuring the rate of conversion ofl-[14C]arginine tol-[14C]citrulline. Protein levels of endothelial (e) and neuronal (n) NOS were determined by Western blot analysis. Arterial pressure (AP) increased ( P < 0.05) during acute and prolonged ANG II infusion. Ca2+-dependent NOS activity values (pmol of citrulline · min−1 · g wet wt−1) for control rats were 21 ± 9 in mesenteric arteries, 13 ± 7 in left ventricle, 14 ± 8 in renal cortex, and 411 ± 70 in renal medulla. Acute ANG II infusion increased ( P < 0.05) Ca2+-dependent NOS activity in renal cortex and renal medulla (81 ± 18 and 611 ± 48, respectively), but no differences were found in mesenteric arteries and left ventricle with respect to control rats. In contrast to the renal changes in NOS activity, acute ANG II infusion did not modify eNOS or nNOS expression in any of the tissues examined. Prolonged ANG II infusion increased ( P < 0.05) Ca2+-dependent NOS activity in mesenteric arteries (70 ± 17), renal cortex (104 ± 31), and left ventricle (49 ± 8) and did not elicit changes in renal medulla. After a prolonged ANG II infusion, eNOS and nNOS levels increased in all tissues examined with the exception of eNOS in the mesenteric arteries and nNOS in the left ventricle, which were not altered. Acute and prolonged phenylephrine infusion elevated AP to a similar extent as ANG II but only elicited significant increments of Ca2+-dependent NOS activity in renal cortex. These data indicate that acute and prolonged elevations in ANG II upregulate Ca2+-dependent NOS activity and protein expression in different tissues related to the control of blood pressure. However, these ANG II effects are heterogeneous with respect to the tissue implicated, the time course of the stimulation, and the NOS isoform involved. Phenylephrine only induces a significant elevation of Ca2+-dependent NOS activity in renal cortex.

Sodium Status Affects Gc-B Natriuretic Peptide Receptor mRNA Levels, but Not Gc-A Or C Receptor Mrna Levels, in the Sheep Kidney

1994 ◽  
Vol 86 (5) ◽  
pp. 517-522 ◽  
Author(s):  
Margaret B. Fraenkel ◽  
G. Peter Aldred ◽  
John G. McDougall
Keyword(s):  
Natriuretic Peptide ◽  
Transcriptional Control ◽  
Renal Cortex ◽  
Renal Medulla ◽  
Mrna Levels ◽  
Binding Studies ◽  
Renal Vasculature ◽  
Receptor Mrna ◽  
Natural Ligand ◽  
Significant Difference

1. In humans and experimental animals the natriuresis and diuresis resulting from infusion of atrial natriuretic peptide varies with the sodium status of the subject. Tissue binding studies have suggested that this may be related to changes in the renal receptors for the hormone. 2. In order to establish whether these changes are under transcriptional control, we examined the levels of mRNA for the three natriuretic peptide receptors [GC-A, GC-B and clearance (C) receptors] in renal cortex and medulla from six sodium-loaded, six sodium-depleted and four control sheep. cDNA probes specific to each receptor were generated using the polymerase chain reaction. 3. GC-B receptor mRNA levels were increased approximately two-fold in the renal cortex of sodium-depleted animals, whereas there was no influence on GC-B receptor mRNA levels in the renal medulla. There was no significant difference in mRNA levels for the GC-A and C receptors. 4. At present the role of the GC-B receptor and its natural ligand C-type natriuretic peptide in the control of renal function is unknown. The present experiments imply some intrarenal function for the GC-B receptor and its natural ligand, although the site of any such function, e.g. renal vasculature or tubules, remains unclear. In addition, we have shown that if GC-A and C receptor levels in the sheep are modulated by sodium, the regulation occurs beyond the level of gene transcription.

scholarly journals Renal Expression and Urinary Excretion of Na-K-2Cl Cotransporter in Obstructive Nephropathy

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Anabel Brandoni ◽  
Adriana M. Torres
Keyword(s):  
Urinary Excretion ◽  
Urinary Tract Obstruction ◽  
Kidney Injury ◽  
Obstructive Nephropathy ◽  
Mrna Levels ◽  
Membrane Expression ◽  
Renal Handling ◽  
Almost All ◽  
Apical Membranes ◽  
Renal Expression

Renal damage due to urinary tract obstruction accounts for up to 30% of acute kidney injury in paediatrics and adults. Bilateral ureteral obstruction (BUO) is associated with polyuria and reduced urinary concentrating capacity. We investigated the renal handling of water and electrolytes together with the renal expression and the urinary excretion of the Na-K-Cl cotransporter (NKCC2) after 1 (BUO-1), 2 (BUO-2), and 7 (BUO-7) days of release of BUO. Immunoblotting and immunohistochemical studies showed that NKCC2 expression was upregulated in apical membranes both from BUO-2 and from BUO-7 rats. The apical membrane expression, where NKCC2 is functional, may be sufficient to normalize water, potassium, sodium, and osmolytes tubular handling. NKCC2 abundance in homogenates and mRNA levels of NKCC2 was significantly decreased in almost all groups suggesting a decrease in the synthesis of the transporter. Urinary excretion of NKCC2 was increased in BUO-7 groups. These data suggest that the upregulation in the expression of NKCC2 in apical membranes during the postobstructive phase of BUO could contribute to improving the excretion of sodium and consequently also the excretion of potassium, osmolytes, and water. Moreover, the increase in urinary excretion of NKCC2 in BUO-7 group could be a potential additional biomarker of renal function recovery.

Effects of dietary salt changes on renal renin-angiotensin system in rats

2002 ◽  
Vol 283 (5) ◽  
pp. F995-F1002 ◽  
Author(s):  
Catherine Ingert ◽  
Michèle Grima ◽  
Catherine Coquard ◽  
Mariette Barthelmebs ◽  
Jean-Louis Imbs
Keyword(s):  
Renal Cortex ◽  
Salt Content ◽  
Renin Angiotensin System ◽  
Fold Increase ◽  
Kidney Cortex ◽  
Ang Ii ◽  
Dietary Salt ◽  
High Sodium ◽  
Ace Activity ◽  
Wistar Kyoto

Renin (RA) and angiotensin-converting enzyme (ACE) activities and angiotensinogen, ANG I, and ANG II levels were measured in the kidney (cortex and medulla) and plasma of Wistar-Kyoto rats on a low-sodium (LS; 0.025% NaCl; n= 8), normal-sodium (NS; 1% NaCl; n = 7), or high-sodium (HS; 8% NaCl; n = 7) diet for 21 days. RA, ANG I, and ANG II levels increased in a manner inversely related to sodium content of the diet in both plasma and renal tissues. The LS diet resulted in a 16-, 2.8-, and 1.8-fold increase in plasma RA, ANG I, and ANG II levels, respectively, compared with those in HS rats. In the renal cortex and medulla, RA, ANG I, and ANG II levels were also increased by diminution of dietary salt content but, in contrast to plasma, ANG II levels increased much more than RA or ANG I levels [5.4 (cortex)- and 4.7 (medulla)-fold compared with HS rats]. In summary, we demonstrated variations of ANG II levels in the kidney during dietary salt modifications. Our results confirm that RA and ACE activity are not the steps limiting intrarenal ANG II levels. Nevertheless, despite RA and ACE activity differences between renal cortex and medulla, ANG I and ANG II levels are equivalent in these two tissues; these results argue against a compartmentalization of RAS in these two intrarenal areas.

scholarly journals An immunohistochemical study of aspartate, glutamate, and taurine in rat kidney.

1994 ◽  
Vol 42 (5) ◽  
pp. 621-626 ◽  
Author(s):  
N Ma ◽  
E Aoki ◽  
R Semba
Keyword(s):  
Amino Acids ◽  
Renal Cortex ◽  
Rat Kidney ◽  
Renal Medulla ◽  
Loop Of Henle ◽  
Immunoperoxidase Method ◽  
Collecting Tubules ◽  
Convoluted Tubules ◽  
Thin Portion ◽  
Intrarenal Distribution

Biochemical studies have revealed considerable amounts of free amino acids in the kidney. We examined the intrarenal distribution of three amino acids (aspartate, glutamate, and taurine) in the rat kidney with an immunoperoxidase method. In the renal cortex, all three amino acids were concentrated in the renal corpuscles and in the epithelia of the collecting tubules. Immunostaining of the collecting tubules was more intense in the principal cells than in the intercalated cells. The distal convoluted tubules were also immunostained with aspartate- and glutamate- specific antibodies but not with the taurine-specific antibody. In the renal medulla, the immunoreactivity specific for aspartate and for glutamate was similar; it was weak in the thick portion of the loop of Henle and strong in the collecting tubules. Immunoreactivity specific for taurine was restricted to regions within the epithelia of the thin portion of the loop of Henle and the collecting tubules. The significance of the accumulated amino acids as osmoregulatory agents is discussed.

Abstract 315: Efficacy and Safety of Rivaroxaban in in vitro Experiments With the Endothelial Cells

2016 ◽  
Vol 119 (suppl_1) ◽  
Author(s):  
Kaname Seki ◽  
Yosuke Mizuno ◽  
Toku Sakashita ◽  
Jun Tanno ◽  
Shintaro Nakano ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Time Course ◽  
Umbilical Vein ◽  
Endothelial Damage ◽  
Coagulation Cascade ◽  
Elisa Assay ◽  
Mrna Levels ◽  
Factor X ◽  
Clotting Factors ◽  
Inflammatory Phase

Aim: Activated factor X (FXa) plays important roles in the thrombin generation and in inflammation, which is evoked during the endothelial damage. Although rivaroxaban is a selective FXa antagonist, it is one of the key therapies in ischemic heart disease, and yet its function in the state of inactivated coagulation cascade is uncertain. Rivaroxaban blocks FXa in the blood but not the tissue, while factor X is converted to FXa only when glutamic acid is changed to γ-carboxyglutamic acid by vitamin K following the intrinsic clotting factors and/or cellular injury activation. To uncover this aspect, we performed the following experiments. Methods and results: Human umbilical vein endothelial cells (HUVECs) were obtained from Lonza Co., Ltd. The cells were grown to 80% confluence and were treated with rivaroxaban (100nM, 500nM, 1000nM, 2000nM respectively) without FXa stimulation for 4 h, 10 h or 24 h. Cells and medium were collected and then their RNA was extracted from the cells. The qPCR of MCP-1, PAR1-4 and the DNA micro arrays (The GeneChip Human Gene 2.0 ST Array, Affymetrix) were performed. There was neither increased nor decreased gene expression significantly in either experimental time course of the qPCRs or the the DNA micro arrays. The ELISA assay of MCP-1 with medium showed non-activated MCP-1. As a next step, cells were treated with 100nM FXa and with/without rivaroxaban in same time course, and cells and medium were collected for further experiments. FXa evoked induction of mRNA levels for several pro-inflammatory cytokines including MCP-1 maximally at 4h, whereas MCP-1 was maximally evoked at 24 h in ELISA assay. Interestingly rivaroxaban inhibited both in all time course, at 4 hour inflammatory phase and at 24 hour inflammatory phase. Conclusion: Collectively, these results suggest that rivaroxaban may be safe in the inactivated coagulation state, and has the efficacy to attenuate the endothelial damage evoked by FXa and by pro-inflammatory cytokine genes.

Abstract 101: Tissue-specific Deletion of Collectrin in the Proximal Tubular Epithelium Increases Arterial Pressure and Augments Salt-sensitivity

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Sylvia Cechova ◽  
Pei-Lun Chu ◽  
Joseph C Gigliotti ◽  
Fan Chan ◽  
Thu H Le
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Renal Blood Flow ◽  
Collecting Duct ◽  
Critical Role ◽  
Specific Effect ◽  
Salt Sensitivity ◽  
Kidney Cortex ◽  
Mrna Levels ◽  
Proximal Tubular

Background: Collectrin ( Tmem27 ) is a key regulator of blood pressure (BP) and modulator of the bioavailability of nitric oxide (NO) and superoxide. It is highly expressed in the kidney in the proximal tubule (PT), collecting duct, and throughout the vascular endothelium. We reported that collectrin plays a critical role as a chaperone for the reabsorption of all amino acids (AAs) in the PT, and for the uptake of the cationic AA L-arginine (L-Arg) in endothelial cells. Global collectrin knockout ( Tmem27 Y/- ) mice display baseline hypertension (HTN), augmented salt-sensitive hypertension (SSH), and decreased renal blood flow. Objective and Methods: To determine the PT-specific effect of collectrin on BP homeostasis and salt sensitivity, we used the Cre -loxP approach and PEPCK-Cre to generate a mouse line lacking collectrin specifically in the PT-- PEPCK-Cre + Tmem27 Y/Flox mice. PEPCK-Cre - Tmem27 Y/Flox mice were used as control. Radiotelemetry was used to measure BP for 2 weeks at baseline and 2 weeks on high salt diet (HSD). Renal blood flow at baseline and on HSD was measured using contrast enhanced ultrasound in the same mice. Results: Successful deletion of collectrin in the PT was confirmed by assessing mRNA levels using real-time RT-PCR, immunohistochemistry staining of renal tissues using anti-collectrin antibody, and quantitation of protein from kidney cortex by Western analysis. Compared to control PEPCK-Cre - Tmem27 Y/Flox mice (n=6), PEPCK-Cre + Tmem27 Y/Flox mice (n=6) displayed significantly higher systolic BP (SBP) at baseline (120.0 ± 2.5 vs 131.6 ± 2.9 mm Hg; p = 0.014) and after HSD (135.3 ± 2.6 vs 151.5 ± 5.2 mm Hg; p = 0.019). Renal blood flow was not different between groups, at baseline nor after HSD. Conclusion: Collectrin in the PT plays an important role in blood pressure homeostasis and response to sodium intake, independent of renal blood flow. Increasing proximal tubular collectrin activity may be a novel therapeutic strategy for the treatment of hypertension and salt-sensitivity.

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