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.

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.

scholarly journals Diffusive shunting of gases and other molecules in the renal vasculature: physiological and evolutionary significance

2016 ◽  
Vol 311 (5) ◽  
pp. R797-R810 ◽  
Author(s):  
Jennifer P. Ngo ◽  
Connie P.C. Ow ◽  
Bruce S. Gardiner ◽  
Saptarshi Kar ◽  
James T. Pearson ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Carbon Dioxide ◽  
Hydrogen Sulfide ◽  
Mathematical Models ◽  
Renal Cortex ◽  
Renal Medulla ◽  
Evolutionary Significance ◽  
Renal Vasculature ◽  
Vasa Recta ◽  
Arteries And Veins

Countercurrent systems have evolved in a variety of biological systems that allow transfer of heat, gases, and solutes. For example, in the renal medulla, the countercurrent arrangement of vascular and tubular elements facilitates the trapping of urea and other solutes in the inner medulla, which in turn enables the formation of concentrated urine. Arteries and veins in the cortex are also arranged in a countercurrent fashion, as are descending and ascending vasa recta in the medulla. For countercurrent diffusion to occur, barriers to diffusion must be small. This appears to be characteristic of larger vessels in the renal cortex. There must also be gradients in the concentration of molecules between afferent and efferent vessels, with the transport of molecules possible in either direction. Such gradients exist for oxygen in both the cortex and medulla, but there is little evidence that large gradients exist for other molecules such as carbon dioxide, nitric oxide, superoxide, hydrogen sulfide, and ammonia. There is some experimental evidence for arterial-to-venous (AV) oxygen shunting. Mathematical models also provide evidence for oxygen shunting in both the cortex and medulla. However, the quantitative significance of AV oxygen shunting remains a matter of controversy. Thus, whereas the countercurrent arrangement of vasa recta in the medulla appears to have evolved as a consequence of the evolution of Henle’s loop, the evolutionary significance of the intimate countercurrent arrangement of blood vessels in the renal cortex remains an enigma.

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.

Role of glucocorticoids in the maturation of renal cortical Na+/H+ exchanger activity during fetal life in sheep

1995 ◽  
Vol 268 (4) ◽  
pp. F710-F717 ◽  
Author(s):  
E. N. Guillery ◽  
L. P. Karniski ◽  
M. S. Mathews ◽  
W. V. Page ◽  
J. Orlowski ◽  
...  
Keyword(s):  
Proximal Tubule ◽  
Renal Cortex ◽  
Membrane Vesicles ◽  
Sodium Reabsorption ◽  
Fetal Life ◽  
Maximal Velocity ◽  
Mrna Levels ◽  
Significant Difference ◽  
Microvillus Membrane

We have studied the role of glucocorticoids in inducing the maturation in activity of the proximal tubule Na+/H+ exchanger that follows birth. Renal cortical microvillus membrane vesicles were prepared from 132-day gestation sheep fetuses (n = 8) that had received intraperitoneal cortisol (13 micrograms.kg-1.h-1) for the previous 48 h. Membrane vesicles were also obtained from sham-operated twin controls (n = 8). Amiloride-sensitive uptake of 22Na+ by these vesicles was measured, and Woolf-Augustinsson-Hofstee plots were used to determine the Michaelis constant (Km) and maximal velocity (Vmax). There was no significant difference in Km; however, the Vmax was 61% higher in cortisol-treated fetuses. Posttreatment circulating cortisol levels were significantly higher in the treated fetuses. Total RNA was collected from renal cortex of the eight pairs of twins when killed. Renal cortex Na+/H+ exchanger 3 (NHE3) mRNA levels were approximately fourfold higher in cortisol-treated than in control fetuses. Although proximal tubule Na+/H+ exchanger activity and renal cortex NHE3 mRNA levels increased significantly in cortisol-treated fetuses, cortisol infusion did not stimulate renal sodium reabsorption in the fetus but rather produced a natriuresis. These results demonstrate that glucocorticoids can induce an increase in both Na+/H+ exchanger activity and NHE3 mRNA levels during the last trimester of gestation in sheep. However, these changes are not associated with an increased ability of the fetal kidney to reabsorb sodium.

Ryanodine and dihydropyridine binding patterns and ryanodine receptor mRNA levels in myopathic hamster heart

1994 ◽  
Vol 267 (3) ◽  
pp. H1205-H1213 ◽  
Author(s):  
W. G. Lachnit ◽  
M. Phillips ◽  
K. J. Gayman ◽  
I. N. Pessah
Keyword(s):  
Binding Sites ◽  
Receptor Activation ◽  
Mrna Levels ◽  
Functional Changes ◽  
Cardiomyopathic Hamster ◽  
Receptor Mrna ◽  
Significant Difference ◽  
Voltage Dependent ◽  
Hamster Heart ◽  
Ca2 Channels

We have determined the densities of sarcolemmal voltage-dependent Ca2+ channels (VDCC) and Ca(2+)-induced Ca2+ release channels (CICR) of sarcoplasmic reticulum (SR) in the cardiomyopathic hamster heart using [3H]PN-200 and [3H]ryanodine, respectively. Partially purified cardiac membrane preparations from myopathic animals exhibit a twofold higher capacity to bind both [3H]PN-200 and [3H]ryanodine. Crude particulate membrane fractions from normal and cardiomyopathic animals reveal no significant difference in receptor densities for [3H]PN-200, whereas densities for [3H]ryanodine binding sites and mRNA levels are significantly (P < 0.05) diminished in cardiomyopathic animals. Inhibition of [3H]ryanodine binding by either Ca2+ or Mg2+ (in mM) as well as temperature dependence for receptor activation for [3H]ryanodine (Q10) is not significantly different, whereas membranes isolated from cardiomyopathic hearts are 1.4-fold and threefold more sensitive to activation by doxorubicin and Ca2+ (in microM), respectively. Vesicles isolated from myopathic hearts are more sensitive to inhibition of Ca2+ uptake by doxorubicin. The higher densities of binding sites for [3H]PN-200 and [3H]ryanodine observed in partially purified membrane fractions from cardiomyopathic hearts are more likely the result of altered patterns with which T-tubule and CICR channels fractionate in preparations from cardiomyopathic hamster heart rather than transcriptional upregulation and may be a consequence of the deficiency in a dystrophin-associated glycoprotein recently identified. Downregulation and functional changes in CICR channels may alter SR Ca2+ transport and contribute to the progression of cardiomyopathy in the hamster.

Renal Na+/H+ exchanger isoforms and their regulation by thyroid hormone

1996 ◽  
Vol 270 (2) ◽  
pp. C585-C592 ◽  
Author(s):  
K. K. Azuma ◽  
D. F. Balkovetz ◽  
C. E. Magyar ◽  
L. Lescale-Matys ◽  
Y. Zhang ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Proximal Tubule ◽  
Renal Cortex ◽  
Blot Hybridization ◽  
Mrna Level ◽  
Kinetic Studies ◽  
Hormone Treatment ◽  
Mrna Levels ◽  
Thyroid Status ◽  
Significant Difference

Na+ crosses the luminal membrane of the proximal tubule primarily via Na+/H+ exchange (NHE), and NHE activity is influenced by thyroid status. Pharmacological, immunological, and kinetic studies indicate multiple isoforms of NHE, and four full-length cDNAs have been cloned to date. The aims of this study were to determine which NHE mRNAs (NHE1, -2, -3, and -4) were expressed in the rat proximal tubule, the relative abundance of each in the renal cortex, and the effect of thyroid status on their expression. By blot hybridization of poly(A)+ RNA, all NHE isoform mRNAs were detected in the rat renal cortex; NHE1, -2, and -3 in the proximal tubule; and NHE1 and -3 in LLC-PK1 cells. NHE3 mRNA abundance was fourfold higher than the other three isoforms in renal cortex. The effect of thyroid status was assessed in renal cortex from euthyroid, hypothyroid, and hyperthyroid rats. Although none of the NHE mRNA levels was altered in the transition from euthyroid to hypothyroid states, both NHE2 and NHE3 mRNA levels increased 1.5-fold in the transition from hypo- to hyperthyroidism. NHE3 protein, measured by immunoblot with the use of an NHE3-specific antibody, was detected at 83-85 kDa in renal cortex and codistributed on sorbitol gradients with the brush-border marker alkaline phosphatase. No significant difference in NHE3 protein abundance was detected between hypothyroid and hyperthyroid rats. In conclusion, in the renal cortex, the NHE3 isoform predominates at the mRNA level, is expressed in apical membranes, and increases at the mRNA but not the protein levels in response to thyroid hormone treatment, suggesting parallel changes in synthesis and turnover of NHE3 by thyroid hormone.

Diffusional kurtosis imaging of kidneys in patients with hyperuricemia: initial study

2019 ◽  
Vol 61 (6) ◽  
pp. 839-847
Author(s):  
Zhong-Yuan Cheng ◽  
You-Zhen Feng ◽  
Xiao-Ling Liu ◽  
Yao-Jiang Ye ◽  
Jun-Jiao Hu ◽  
...  
Keyword(s):  
Renal Function ◽  
Fractional Anisotropy ◽  
Renal Cortex ◽  
Gouty Arthritis ◽  
Mean Diffusivity ◽  
Renal Medulla ◽  
Diffusion Kurtosis Imaging ◽  
Imaging Data ◽  
Significant Difference ◽  
Diffusion Kurtosis

Background At present, there remains a lack of a reliable indicator for monitoring renal function in patients with hyperuricemia. Purpose This study aimed to evaluate the feasibility of diffusion kurtosis imaging in the assessment of renal function in patients with hyperuricemia. Material and Methods A total of 75 male participants, including 25 with asymptomatic hyperuricemia, 25 with gouty arthritis, and 25 age-matched male healthy controls, were enrolled in this study. Diffusion kurtosis imaging data were acquired to derive axial (Ka), radial (Kr), and mean kurtosis (MK), fractional anisotropy, axial (Da), radial (Dr), and mean diffusivity (MD) for comparisons among the three groups. They were also correlated with estimated glomerular filtration rate (eGFR). Results The MK values of the renal cortex and medulla and Kr value of the renal medulla in patients with asymptomatic hyperuricemia and gouty arthritis significantly increased compared with those in the controls ( P < 0.05). Patients with gouty arthritis showed significant higher cortical and medullary Ka values compared with the other two groups ( P < 0.05). The cortical Kr values of the asymptomatic hyperuricemia and gouty arthritis patients were significantly higher than that of the controls ( P < 0.05). The medullary fractional anisotropy value showed a significant difference between the control and gouty arthritis groups ( P < 0.05). No correlation was found between any diffusion kurtosis imaging parameters and eGFR value. Conclusion Diffusion kurtosis imaging is feasible in the assessment of the early changes of renal cortex and medulla in patients with hyperuricemia.

scholarly journals Significant association of interleukin 10 receptor mRNA levels with renal cell carcinoma metastasis

2008 ◽  
Vol 29 (1) ◽  
pp. 19-25 ◽  
Author(s):  
Hideyuki ABE ◽  
Tomonori YAMANISHI ◽  
Tomoko MASHIDORI ◽  
Kyoko ARAI ◽  
Takao KAMAI
Keyword(s):  
Renal Cell Carcinoma ◽  
Cell Carcinoma ◽  
Renal Cell ◽  
Interleukin 10 ◽  
Mrna Levels ◽  
Receptor Mrna ◽  
Renal Cell Carcinoma Metastasis ◽  
Carcinoma Metastasis

Mechanical activity in heart regulates translation of α-myosin heavy chain mRNA but not its localization

1999 ◽  
Vol 276 (6) ◽  
pp. H2013-H2019 ◽  
Author(s):  
Gordana Nikcevic ◽  
Maria C. Heidkamp ◽  
Merja Perhonen ◽  
Brenda Russell
Keyword(s):  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Mrna Translation ◽  
Neonatal Rat ◽  
Mechanical Activity ◽  
Mrna Levels ◽  
Rat Cardiomyocytes ◽  
Significant Difference ◽  
Polysomal Fraction ◽  
Mechanical Transduction

Mechanical inactivity depresses protein expression in cardiac muscle tissue and results in atrophy. We explore the mechanical transduction mechanism in spontaneously beating neonatal rat cardiomyocytes expressing the α-myosin heavy chain (α-MyHC) isoform by interfering with cross-bridge function [2,3-butanedione monoxime (BDM), 7.5 mM] without affecting cell calcium. The polysome content and α-MyHC mRNA levels in fractions from a sucrose gradient were analyzed. BDM treatment blocked translation at initiation (162 ± 12% in the nonpolysomal RNA fraction and 43 ± 6% in the polysomal fraction, relative to control as 100%; P < 0.05). There was an increase in α-MyHC mRNA from the nonpolysomal fraction (120.5 ± 7.7%; P < 0.05 compared with control) with no significant change in the heavy polysomes. In situ hybridization of α-MyHC mRNA was used to estimate message abundance as a function of the distance from the nucleus. The mRNA was dispersed through the cytoplasm in spontaneously beating cells as well as in BDM-treated cells (no significant difference). We conclude that direct inhibition of contractile machinery, but not calcium, regulates initiation of α-MyHC mRNA translation. However, calcium, not pure mechanical signals, appears to be important for message localization.

Alteration of Atrial Natriuretic Peptide and Brain Natriuretic Peptide Gene Expression Associated with Progression and Regression of Cardiac Hypertrophy in Renovascular Hypertensive Rats

1996 ◽  
Vol 90 (3) ◽  
pp. 197-204 ◽  
Author(s):  
Hideo Kawakami ◽  
Hideki Okayama ◽  
Mareomi Hamada ◽  
Kunio Hiwada
Keyword(s):  
Gene Expression ◽  
Atrial Natriuretic Peptide ◽  
Cardiac Hypertrophy ◽  
Brain Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Mrna Levels ◽  
Hypertensive Rats ◽  
Regression Of Cardiac Hypertrophy ◽  
Peptide Gene ◽  
Atrial Natriuretic

1. We assessed the changes of atrial natriuretic peptide and brain natriuretic peptide gene expression associated with progression and regression of cardiac hypertrophy in renovascular hypertensive rats (RHR). 2. Two-kidney, one-clip hypertensive rats (6-week-old male Wistar) were made and studied 6 (RHR-1) and 10 weeks (RHR-2) after the procedure. Regression of cardiac hypertrophy was induced by nephrectomy at 6 weeks after constriction, and the nephrectomized rats were maintained further for 4 weeks (nephrectomized rat: NEP). Sham operation was performed, and the rats were studied after 6 (Sham-1) and 10 weeks (Sham-2). Atrial natriuretic peptide and brain natriuretic peptide gene expression in the left ventricle was analysed by Northern blotting. 3. Plasma atrial natriuretic peptide and brain natriuretic peptide were significantly higher in RHR-1 and RHR-2 than in Sham-1, Sham-2 and NEP. Atrial natriuretic peptide and brain natriuretic peptide mRNA levels in RHR-1 were approximately 7.2-fold and 1.8-fold higher than those in Sham-1, respectively, and the corresponding levels in RHR-2 were 13.0-fold and 2.4-fold higher than those in Sham-2, respectively. Atrial natriuretic peptide and brain natriuretic peptide mRNA levels of NEP were normalized. Levels of atrial natriuretic peptide and brain natriuretic peptide mRNA were well correlated positively with left ventricular weight/body weight ratios. There was a significant positive correlation between the levels of atrial natriuretic peptide and brain natriuretic peptide mRNA (r = 0.86, P<0.01). 4. We conclude that the expression of atrial natriuretic peptide and brain natriuretic peptide genes is regulated in accordance with the degree of myocardial hypertrophy and that the augmented expression of these two natriuretic peptides may play an important role in the maintenance of cardiovascular haemodynamics in renovascular hypertension.

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