Ontogeny of triamcinolone-acetonide binding sites in outer cortical tissue from rat kidneys

1985 ◽  
Vol 249 (6) ◽  
pp. F891-F897
Author(s):  
A. Aperia ◽  
L. A. Haldosen ◽  
L. Larsson ◽  
J. A. Gustafsson
Keyword(s):  
Triamcinolone Acetonide ◽  
Binding Sites ◽  
Cortical Tissue ◽  
Tubular Cells ◽  
Proximal Tubular ◽  
Old Rats ◽  
In Vivo Administration ◽  
Adrenalectomized Rats ◽  
Intact Rats

The ontogeny of glucocorticoid binding sites and the glucocorticoid hormone (GC) feedback control of available glucocorticoid binding sites was studied using the cytosolic fraction of outer cortical tissue obtained from kidneys in 20- and 40-day-old intact and adrenalectomized rats. Morphometric analysis showed that this tissue contained 85.7% (20 days) and 88.7% (40 days) of proximal tubular cells. Glucocorticoid binding sites were determined by [3H]triamcinolone-acetonide (TA) binding and isoelectric focusing analysis. In intact rats, TA binding sites (fmol/mg DNA) were significantly higher at 20 (3,624) than at 40 (1,640) days. Adrenalectomy significantly increased TA binding sites (fmol/mg DNA) at 40 (to 8,445) but not at 20 days. TA binding sites related to DNA were significantly higher in 20- than in 40-day-old intact rats and significantly higher in 40- than in 20-day-old adrenalectomized rats. Serum corticosterone (nM) was not significantly different in 20- (230) and 40- (189) day-old rats. After in vivo administration of a synthetic GC, TA binding sites were replenished to the cytosol after 20-24 h. Prolonged GC treatment (1-60 micrograms X 100 g body wt-1 X day-1) depressed the replenishment of TA binding sites significantly more in 40- than in 20-day-old adrenalectomized rats. Kd was determined in both intact and adrenalectomized 20- and 40-day-old rats and ranged between 1.30 and 4.33 nM. The steroidal specificity for the TA binding sites was the same in 20- and 40-day-old rats.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals The effect of proteinuria-mediated endothelin-1 downregulation of PKCα signalling in proximal tubular cells and its successful/INS; treatment is measurable using microRNA15a as biomarker in vitro and in vivo

Life Sciences ◽  
2013 ◽  
Vol 93 (25-26) ◽  
pp. e5-e6
Author(s):  
Heike Loeser ◽  
Melanie von Brandenstein ◽  
Maike Wittersheim ◽  
Volker Burst ◽  
Claudia Richter ◽  
...  
Keyword(s):  
Proximal Tubular Cells ◽  
Tubular Cells ◽  
Endothelin 1 ◽  
Proximal Tubular

scholarly journals The Role of Cystinosin in the Intermediary Thiol Metabolism and Redox Homeostasis in Kidney Proximal Tubular Cells

Antioxidants ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 179 ◽  
Author(s):  
Rodolfo Sumayao ◽  
Philip Newsholme ◽  
Tara McMorrow
Keyword(s):  
Redox Homeostasis ◽  
In Vitro Models ◽  
Cellular Redox ◽  
Tubular Cells ◽  
Thiol Metabolism ◽  
Proximal Tubular ◽  
Kidney Proximal Tubular Cells

Cystinosin is a lysosomal transmembrane protein which facilitates transport of the disulphide amino acid cystine (CySS) from the lysosomes of the cell. This protein is encoded by the CTNS gene which is defective in the lysosomal storage disorder, cystinosis. Because of the apparent involvement of cystinosin in the intermediary thiol metabolism, its discovery has fuelled investigations into its role in modulating cellular redox homeostasis. The kidney proximal tubular cells (PTCs) have become the focus of various studies on cystinosin since the protein is highly expressed in these cells and kidney proximal tubular transport dysfunction is the foremost clinical manifestation of cystinosis. The lysosomal CySS pool is a major source of cytosolic cysteine (Cys), the limiting amino acid for the synthesis of an important antioxidant glutathione (GSH) via the γ-glutamyl cycle. Therefore, loss of cystinosin function is presumed to lead to cytosolic deficit of Cys which may impair GSH synthesis. However, studies using in vitro models lacking cystinosin yielded inconsistent results and failed to establish the mechanistic role of cystinosin in modulating GSH synthesis and redox homeostasis. Because of the complexity of the metabolic micro- and macro-environment in vivo, using in vitro models alone may not be able to capture the complete sequence of biochemical and physiological events that occur as a consequence of loss of cystinosin function. The coexistence of pathways for the overall handling and disposition of GSH, the modulation of CTNS gene by intracellular redox status and the existence of a non-canonical isoform of cystinosin may constitute possible rescue mechanisms in vivo to remediate redox perturbations in renal PTCs. Importantly, the mitochondria seem to play a critical role in orchestrating redox imbalances initiated by cystinosin dysfunction. Non-invasive techniques such as in vivo magnetic resonance imaging with the aid of systems biology approaches may provide invaluable mechanistic insights into the role of cystinosin in the essential intermediary thiol metabolism and in the overall regulation cellular redox homeostasis.

11 beta-Hydroxysteroid dehydrogenase mRNA expression in rat kidney

1991 ◽  
Vol 260 (5) ◽  
pp. F764-F767
Author(s):  
J. L. Yau ◽  
A. D. Van Haarst ◽  
M. P. Moisan ◽  
S. Fleming ◽  
C. R. Edwards ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Binding Sites ◽  
Mineralocorticoid Receptor ◽  
Rat Kidney ◽  
Hydroxysteroid Dehydrogenase ◽  
Mineralocorticoid Receptors ◽  
Tubular Cells ◽  
Renal Tubular

11 beta-Hydroxysteroid dehydrogenase (11 beta-OHSD) protects nonspecific renal mineralocorticoid receptors from exposure to circulating glucocorticoid in vivo by catalyzing the conversion of corticosterone to inactive 11-dehydrocorticosterone. Although 11 beta-OHSD bioactivity and aldosterone binding sites are found in distal tubular cells, mineralocorticoid receptor and 11 beta-OHSD immunoreactivities are not colocalized. However, there are several kidney isoforms of 11 beta-OHSD, not all of which may be immunoreactive, whereas only a single mRNA species has been described. Using in situ hybridization we found 11 beta-OHSD mRNA is highly expressed in all renal tubular epithelia in the rat. It is therefore likely that 11 beta-OHSD is colocalized with mineralocorticoid receptors in distal tubular cells.

In vivo administration of interleukin-1α induces muscle proteolysis in normal and adrenalectomized rats

Metabolism ◽  
1993 ◽  
Vol 42 (2) ◽  
pp. 204-208 ◽  
Author(s):  
Oded Zamir ◽  
Per-Olof Hasselgren ◽  
Daniel von Allmen ◽  
Josef E. Fischer
Keyword(s):  
Interleukin 1Α ◽  
In Vivo Administration ◽  
Adrenalectomized Rats

Aldosterone in colonic potassium adaptation in rats

1988 ◽  
Vol 117 (3) ◽  
pp. 379-386 ◽  
Author(s):  
C. J. Edmonds ◽  
C. L. Willis
Keyword(s):  
Sodium Transport ◽  
Plasma Potassium ◽  
Replacement Treatment ◽  
Potassium Adaptation ◽  
Complete Adaptation ◽  
Potassium Secretion ◽  
Potassium Loading ◽  
Adrenalectomized Rats ◽  
Intact Rats

ABSTRACT The influence of adrenalectomy and administration of aldosterone on potassium secretion by colonic epithelium was studied in vivo in rats, particularly in relation to potassium adaptation (induced by feeding a potassium-rich diet) and the response to acute i.v. administration of a potassium load. Adrenalectomy (rats maintained on dexamethasone and saline) impaired the development of potassium adaptation or considerably reduced it if the rats had been previously adapted. The partial adaptation observed in the adrenalectomized rats may be related to the increased plasma potassium concentration developed when these rats received the potassium-rich diet. Within 2 h of acute aldosterone administration, the response of the potassium secretion rate to acute potassium loading in adrenalectomized rats was significantly improved. When aldosterone (2 μg/day per 100 g body weight, given by osmotic minipump) was added to the replacement treatment, the plasma concentration of potassium was similar to that of the intact rats, and both potassium adaptation and the response to the acute potassium load were completely restored. Transepithelial potential difference and sodium transport were not stimulated, being similar to the values in intact rats. Considerable changes in potassium secretion induced by acute potassium loading did not significantly affect sodium transport. The findings suggest that the sodium and potassium epithelial pathways are, to a large extent, independently influenced by aldosterone. Aldosterone appears to be essential for complete adaptation and, in a relatively low dose, can completely restore potassium adaptation and the response to acute potassium loads in adrenalectomized rats. J. Endocr. (1988) 117, 379–386

scholarly journals Cell Spinpods: A Simple Inexpensive Device to Determine Suspension Culture and Toxicity Effects on Renal Proximal Tubular Cells

2021 ◽  
Author(s):  
Timothy G. Hammond ◽  
Corey Nislow ◽  
Ivan C. Christov ◽  
Vecihi Batuman ◽  
Pranay P. Nagrani ◽  
...  
Keyword(s):  
Suspension Culture ◽  
Industrial Applications ◽  
Proximal Tubular Cells ◽  
Tubular Cells ◽  
Proximal Tubular ◽  
Injection Molded ◽  
Renal Proximal Tubular Cells ◽  
Renal Proximal Tubular

Abstract Rotating forms of suspension culture allow cells to aggregate into spheroids, prevent the de-differentiating influence of adherence to plastic surfaces, and, perhaps most importantly of all, provide physiologically relevant, in vivo levels of shear stress. Suspension culture technology has not, however, been widely implemented, in large part because the vessels are prohibitively expensive, labor-intensive to use, and are difficult to scale for industrial applications. Our solution addresses each of these challenges in a new vessel called a cell spinpod. These small 3.5 mL capacity vessels are constructed from injection molded thermoplastic polymer components. They contain self-sealing axial silicone rubber ports, and fluoropolymer, breathable membranes. Here we report the development of injection molded cell spinpods with two-fluid modeling of the flow and stresses. Their validation was accomplished using immortalized human renal proximal tubular cells for functional assays, renal damage marker release, and differential gene expression analysis via next-generation sequencing. During exposure to myeloma immunoglobulin light chains, rotation increased both toxin-induced cell death, and release of clinically validated nephrotoxicity cytokine markers in a toxin-specific pattern. Cell spinpods are a sensitive tool for detecting nephrotoxicity in vitro.

scholarly journals NADPH oxidase inhibition reduces tubular sodium transport and improves kidney oxygenation in diabetes

2012 ◽  
Vol 302 (12) ◽  
pp. R1443-R1449 ◽  
Author(s):  
Patrik Persson ◽  
Peter Hansell ◽  
Fredrik Palm
Keyword(s):  
Nadph Oxidase ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Diabetic Rats ◽  
Filtration Fraction ◽  
Tubular Cells ◽  
Proximal Tubular ◽  
Oxidase Inhibition ◽  
Streptozotocin Diabetic Rats ◽  
Nadph Oxidase Inhibition

Sustained hyperglycemia is associated with increased oxidative stress resulting in decreased intrarenal oxygen tension (Po2) due to increased oxygen consumption (Qo2). Chronic blockade of the main superoxide radicals producing system, the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, normalizes Qo2 by isolated proximal tubular cells (PTC) and reduces proteinuria in diabetes. The aim was to investigate the effects of acute NADPH oxidase inhibition on tubular Na+ transport and kidney Po2 in vivo. Glomerular filtration rate (GFR), renal blood flow (RBF), filtration fraction (FF), Na+ excretion, fractional Li+ excretion, and intrarenal Po2 was measured in control and streptozotocin-diabetic rats during baseline and after acute NADPH oxidase inhibition using apocynin. The effects on tubular transporters were investigated using freshly isolated PTC. GFR was increased in diabetics compared with controls (2.2 ± 0.3 vs. 1.4 ± 0.1 ml·min−1·kidney−1). RBF was similar in both groups, resulting in increased FF in diabetics. Po2 was reduced in cortex and medulla in diabetic kidneys compared with controls (34.4 ± 0.7 vs. 42.5 ± 1.2 mmHg and 15.7 ± 1.2 vs. 25.5 ± 2.3 mmHg, respectively). Na+ excretion was increased in diabetics compared with controls (24.0 ± 4.7 vs. 9.0 ± 2.0 μm·min−1·kidney−1). In controls, all parameters were unaffected. However, apocynin increased Na+ excretion (+112%) and decreased fractional lithium reabsorption (−10%) in diabetics, resulting in improved cortical (+14%) and medullary (+28%) Po2. Qo2 was higher in PTC isolated from diabetic rats compared with control. Apocynin, dimethylamiloride, and ouabain reduced Qo2, but the effects of combining apocynin with either dimethylamiloride or ouabain were not additive. In conclusion, NADPH oxidase inhibition reduces tubular Na+ transport and improves intrarenal Po2 in diabetes.

Effect of betamethasone on Na-K-ATPase activity and basal and lateral cell membranes in proximal tubular cells during early development

1983 ◽  
Vol 245 (2) ◽  
pp. F232-F237 ◽  
Author(s):  
Y. Igarashi ◽  
A. Aperia ◽  
L. Larsson ◽  
R. Zetterstrom
Keyword(s):  
Atpase Activity ◽  
Cell Membranes ◽  
Time Lag ◽  
Structural Development ◽  
Proximal Tubular Cells ◽  
Maximal Increase ◽  
Tubular Cells ◽  
Proximal Tubular ◽  
Old Rats ◽  
Lateral Cell

The mechanism by which betamethasone induces Na-K-ATPase activity in developing tissue was studied in homogenates of proximal tubular cells from 10-day-old rats. A significant increase in Na-K-ATPase activity occurred after 5 micrograms . 100 g-1 . 12 h-1 X 2 beta-methasone and a maximal increase after 15-60 micrograms . 100 g-1 . 12 h-1 X 2. Following a single dose of 60 micrograms . 100 g-1 betamethasone Na-K-ATPase activity increased significantly after 16 h and maximally after 24-30 h. The 16-h time lag suggests that betamethasone does not act only directly on Na-K-ATPase synthesis. Betamethasone 60 micrograms . 100 g-1 increases Na-K-ATPase activity significantly in kidneys in which glomerular filtration rate is reduced by ureteral ligation, but the increase is significantly less pronounced than in kidneys with intact ureters, suggesting that the induction is not mediated only by alterations in sodium supply. Twenty-four hours after 10-60 micrograms . 100 g-1 betamethasone there was no significant increase in glucose-6-phosphatase and Mg-ATPase activity in 10-day-old rats or in Na-K-ATPase activity in 40-day-old rats. The basal and lateral cell membranes of the proximal tubular cells were not significantly increased 24 h after 60 micrograms . 100 g-1 betamethasone. Accordingly, structural development is not a prerequisite for enzymatic differentiation.

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