scholarly journals Cellular and subcellular localization of enzymes of arginine metabolism in rat kidney

1992 ◽  
Vol 282 (2) ◽  
pp. 369-375 ◽  
Author(s):  
S N Dhanakoti ◽  
M E Brosnan ◽  
G R Herzberg ◽  
J T Brosnan
Keyword(s):  
Rat Kidney ◽  
Subcellular Fractionation ◽  
Kidney Cortex ◽  
Ornithine Aminotransferase ◽  
Outer Medulla ◽  
Argininosuccinate Synthase ◽  
Distal Tubules ◽  
Convoluted Tubules ◽  
Inner Cortex ◽  
Proximal Convoluted Tubules

Rat kidneys extract citrulline derived from the intestinal metabolism of glutamine and convert it stoichiometrically into arginine. This pathway constitutes the major endogenous source of arginine. We investigated the localization of enzymes of arginine synthesis, argininosuccinate synthase and lyase, and of breakdown, arginase and ornithine aminotransferase, in five regions of rat kidney, in cortical tubule fractions and in subcellular fractions of cortex. Argininosuccinate synthase and lyase were found almost exclusively in cortex. Arginase and ornithine aminotransferase were found in inner cortex and outer medulla. Since cortical tissue primarily consists of proximal convoluted and straight tubules, distal tubules and glomeruli, we prepared cortical tubule fragments by collagenase digestion of cortices and fractionated them on a Percoll gradient. Argininosuccinate synthase and lyase were found to be markedly enriched in proximal convoluted tubules, whereas less than 10% of arginase and ornithine aminotransferase, were recovered in this fraction. Arginine production from citrulline was also enriched in proximal convoluted tubules. Subcellular fractionation of kidney cortex revealed that argininosuccinate synthase and lyase are cytosolic. We therefore conclude that arginine synthesis occurs in the cytoplasm of the cells of the proximal convoluted tubule.

scholarly journals Immunohistochemical Localization of Arginine and Citrulline in Rat Renal Tissue

1997 ◽  
Vol 45 (6) ◽  
pp. 875-881 ◽  
Author(s):  
Eiko Aoki ◽  
Ikuo K. Takeuchi
Keyword(s):  
Amino Acids ◽  
Epithelial Cells ◽  
Rat Kidney ◽  
Immunohistochemical Method ◽  
Moderate Intensity ◽  
Outer Medulla ◽  
Collecting Ducts ◽  
Outer Stripe ◽  
Convoluted Tubules ◽  
Proximal Convoluted Tubules

Using antibodies highly specific for L-arginine and L-citrulline, we localized these amino acids in rat kidney with immunohistochemical methods. Highest levels of arginine immunoreactivity were observed in epithelial cells of proximal tubules in the outer stripe of the outer medulla and the collecting ducts in the cortex. Staining intensity of proximal convoluted tubules in the outer stripe decreased from the inner side to the outer side. In the inner medulla, collecting ducts were labeled with moderate intensity. Staining within the cortex was apparent only with collecting ducts. Citrulline immunoreactivity was localized in the epithelial cells of collecting ducts both in the cortex and medulla. Immunoreactivity was also found in glomerular podocytes and in the epithelial cells of proximal convoluted tubules in the outer medulla. These localizations were different from those of other amino acids previously reported. The precise cellular distribution of arginine and citrulline in rat kidney was determined for the first time by an immunohistochemical method in the present study.

scholarly journals Proximal convoluted tubules of the rats kidney--a stereological analysis

2003 ◽  
Vol 3 (1) ◽  
pp. 36-39 ◽  
Author(s):  
Selma Aličelebić
Keyword(s):  
Rat Kidney ◽  
Volume Density ◽  
Kidney Cortex ◽  
Rat Kidney Cortex ◽  
Mean Values ◽  
Quantitative Parameters ◽  
Male Wistar Rats ◽  
Normal Rat ◽  
Convoluted Tubules ◽  
Proximal Convoluted Tubules

Background and Purpose: The aim of this work was to order quantitative parameters of the proximal convoluted tubules (PCT) in the normal rat kidney cortex. Volume density (VV), both surface and specific surface density toward interstitium (SVi and SVi/VV) and toward lumen (SVl and SVl/VV) and thickness (T) of tubules epithelium have been stereologically ordered.Material and Methods: Stereologically were analysed 170 test fields by lattice L36 on the paraffin sections of the three adult male Wistar rats kidney dyeing by PAS-method.Results: The mean values of the variables analysed were Vv=76.4% ±0.012; Svi=0.056pm-1 ±0.004; Svl=0.028pm-1 ±0.003; Svi/Vv=0.073pm-1 ±0.003; Svl/Vv=0.037pm-1 ±0.005; T=18,26pm ±0.897.Conclusions: Stereological methods are making a very valuable contribution to science over recent years. We have used unbiased stereological counting methods to obtain objective quantitative parameters of the PCT epithelium in the normal rats’ kidney cortex.

scholarly journals THE STAGES IN CALCIFICATION OF THE RAT KIDNEY AFTER THE ADMINISTRATION OF URANIUM NITRATE

1953 ◽  
Vol 97 (5) ◽  
pp. 681-694 ◽  
Author(s):  
Lewis K. Dahl
Keyword(s):  
Ferrous Iron ◽  
Rat Kidney ◽  
Cellular Damage ◽  
Appreciable Amount ◽  
Wide Range ◽  
Uranium Nitrate ◽  
Speed Of Evolution ◽  
Dose Levels ◽  
Convoluted Tubules ◽  
Inner Cortex

The anatomical and histochemical alterations in rat kidneys after the parenteral administration of uranium nitrate [UO2(NO3)2·6H2O] have been studied. The histological effects produced by this agent over a wide range of dose levels were nearly identical in character and differed principally in their speed of evolution. The deposition of calcium always began at foci in the cytoplasm of the cells of the proximal convoluted tubules of the inner cortex. It remained intracellular until the cell boundaries were destroyed. Deposits of calcium could be found before any other cellular damage could be demonstrated by histological examination. Later, when degeneration and necrosis were present, the foci of calcification were imperfectly related to them in location or degree. In contrast, the amount of calcification was correlated with the dose of uranium nitrate, being greatest in the kidneys of rats that received 20 mg./kg., next greatest in the 30 mg./kg. rats, less in the 10 mg./kg. rats, and slight in those that received 2 mg./kg. Histochemical stains for ferric and ferrous iron, chondroitinsulfate, and polysaccharides gave results that were negative or unrelated to the deposits of calcium, thus making it unlikely that these substances held any appreciable amount of calcium in the tissue. Yet it is clear that some anion other than phosphate must be combined with part of the calcium; the results with the alizarin and von Kóssa stains confirmed an earlier result (1) in showing that the first deposits of calcium are formed without comparable accumulations of phosphate.

scholarly journals HISTOCHEMICAL STUDIES ON THE UPTAKE OF HORSERADISH PEROXIDASE BY RAT KIDNEY SLICES

1965 ◽  
Vol 27 (2) ◽  
pp. 305-312 ◽  
Author(s):  
A. T. Miller ◽  
D. M. Hale ◽  
K. D. Alexander
Keyword(s):  
Horseradish Peroxidase ◽  
Intracellular Transport ◽  
Rat Kidney ◽  
Kidney Slices ◽  
Metabolic Conditions ◽  
Peroxidase Uptake ◽  
Free Media ◽  
Energy Dependent ◽  
Convoluted Tubules ◽  
Proximal Convoluted Tubules

When rat kidney slices were incubated in the presence of horseradish peroxidase, there was an energy-dependent uptake of the protein by the cells of the kidney tubules. The uptake was greatest in the proximal convoluted tubules and in the thick ascending limbs of the loops of Henle; it was abolished by cold, anoxia, 2,4-dinitrophenol, and fluoroacetate, and was more readily depressed by unfavorable metabolic conditions in the proximal convoluted tubules than in the thick ascending limbs. Protein uptake was inhibited when the kidney slices were incubated in electrolyte-free media. In sodium chloride solutions, uptake was reduced as sodium was progressively replaced by choline, and ouabain inhibited uptake in the proximal convoluted tubules, but not in the thick ascending limbs. To a limited extent, lithium could replace sodium in the incubation medium with no depression of peroxidase uptake. These results suggest that a sodium-stimulated, ouabain-sensitive ATPase may be involved in the uptake of protein by cells of the kidney tubule. The intracellular transport of peroxidase in cells of the proximal convoluted tubules was abolished by cold, anoxia, and 2,4-dinitrophenol, but it was not affected by concentrations of ouabain which inhibited the uptake of the protein.

scholarly journals Phosphomonoesterase hydrolysis of polyphosphoinositides in rat kidney: Properties and subcellular localization of the enzyme system

1975 ◽  
Vol 150 (3) ◽  
pp. 537-551 ◽  
Author(s):  
P H Cooper ◽  
J N Hawthorne
Keyword(s):  
Phosphatase Activity ◽  
Metal Ion ◽  
Rat Kidney ◽  
Gradient Centrifugation ◽  
Sodium Deoxycholate ◽  
Subcellular Fractionation ◽  
Kidney Cortex ◽  
Ph Optimum ◽  
Triton X ◽  
Hydrolysis Of

Tthe properties of diphosphoinositide and triphosphoinositide phosphatases from rat kidney homogenate were studied in an assay system in which non-specific phosphatase activity was eliminated. The enzymes were not completely metal-ion dependent and were activated by Mg2+. The detergent sodium deoxycholate, Triton X-100 and Cutscum inhibited the reaction; cetyltrimethylammonium bromide only activated when added with the subtrates and in the presence Mg2+. Both enzymes had a pH optimum of 7.5. Ca2+ and Li+ both activated triphosphoinositide phosphatase, but Ca2+ inhibited and L+ had little effect on diphosphoinositide phosphatase. Cyclic AMP had no effect on either enzyme. The enzymes were three times more active in kidney cortex than in the medulla. On subcellular fractionation of kidney-cortex homogenates by differential and density-gradient centrifugation, the distribution of the enzymes resembled that of thiamin pyrophosphatase (assayed in the absence of ATP), suggesting localization in the Golgi complex. However, the distribution differed from that of the liver Golgimarker galactosyltransferase. Activities of both diphosphoinositide and triphosphoinositide phosphatases and thiamin pyrophosphatase were low in purified brush-border fragments. Further experiments indicate that at least part of the phosphatase activity is soluble.

Localization of mRNAs coding for isozymes of plasma membrane Ca(2+)-ATPase pump in rat kidney

1992 ◽  
Vol 263 (1) ◽  
pp. F7-F14 ◽  
Author(s):  
M. Magosci ◽  
M. Yamaki ◽  
J. T. Penniston ◽  
T. P. Dousa
Keyword(s):  
Plasma Membrane ◽  
Rat Kidney ◽  
Rat Plasma ◽  
Rt Pcr ◽  
Chain Reaction ◽  
Outer Medulla ◽  
Unique Distribution ◽  
Polymerase Chain ◽  
Convoluted Tubules ◽  
Specific Mrna

We have studied localization of mRNAs coding isozymes of rat plasma membrane Ca(2+)-adenosinetriphosphatase pump (rPMCA) in the rat kidney, with use of reverse transcription (RT) with subsequent amplification by polymerase chain reaction (PCR). When zones of the kidney were separated by macrodissection, a large amount of mRNA coding isozyme rPMCA1 was found in all zones; mRNA for isozyme rPMCA2 was abundant in cortex and in outer medulla, and mRNA for isozyme rPMCA3 was prominent in outer medulla. The mRNAs were analyzed in microdissected cortical nephron segments by use of RT-PCR approach described previously [T. Moriyama, H. R. Murphy, B. M. Martin, and A. Garcia-Perez. Am. J. Physiol. 258 (Renal Fluid Electrolyte Physiol. 27): F1470-F1474, 1990]. We detected mRNA for isozyme rPMCA2 in microdissected distal convoluted tubules (DCT) and in cortical thick ascending limbs (CTAL) and, less consistently, also in proximal convoluted tubule and in glomeruli. The mRNA for isozyme rPMCA1 was abundant in glomeruli but was absent in all examined cortical tubular segments. Our results document that mRNAs for all three major isozymes of rPMCA are present and show a unique distribution in the three major zones of rat renal parenchyma. Specific mRNA coding for rPMCA2 was detected in cortical tubules, namely in CTAL and DCT, whereas mRNA coding isozyme rPMCA1 was found in glomeruli. We suggest that isozyme rPMCA2 might be specifically related to epithelial cells and their function, whereas rPMCA1 is probably a component of nonepithelial cells including these in glomeruli.

scholarly journals Aldose reductase and sorbitol dehydrogenase distribution in rat kidney.

1977 ◽  
Vol 25 (1) ◽  
pp. 1-8 ◽  
Author(s):  
C N Corder ◽  
J G Collins ◽  
T S Brannan ◽  
J Sharma
Keyword(s):  
Aldose Reductase ◽  
Alloxan Diabetes ◽  
Rat Kidney ◽  
Sorbitol Dehydrogenase ◽  
Outer Medulla ◽  
Developing Kidney ◽  
Enzymatic Changes ◽  
Developing Rat ◽  
Convoluted Tubules ◽  
Sorbitol Pathway

The sorbitol pathway catalyzes the conversion of glucose to fructose via the intermediate sorbitol. It consists of aldose reductase (AR) and sorbitol dehydrogenase (SDH). In adult (44 day) kidney zones, AR was highest in the outer medulla. In substructures AR was highest in distal convoluted tubule. The AR was greatest in newborn and 8-day zones of developing rat kidney. Acute alloxan diabetes was associated with decreased AR in small arteries, but not glomeruli. The SDH was lowest in outer medulla. It was most active in glomeruli and distal convoluted tubules. The diabetic state leads to no change of SDH in arteries but an increase in glomeruli. SDH increased with development. This study demonstrates AR and SDH in substructures of the kidney. The pathway is present in developing kidney. In diabetes the enzymatic changes would tend to decrease accumulation of sorbitol.

scholarly journals Phosphatidylinositol kinase and diphosphoinositide kinase of rat kidney cortex: properties and subcellular localization

1976 ◽  
Vol 160 (1) ◽  
pp. 97-105 ◽  
Author(s):  
P H Cooper ◽  
J N Hawthorne
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Complex ◽  
Brush Border ◽  
Rat Kidney ◽  
Subcellular Fractionation ◽  
Kidney Cortex ◽  
Marker Enzymes ◽  
Rat Kidney Cortex ◽  
Phosphatidylinositol Kinase ◽  
Golgi Membranes

The properties of phosphatidylinositol kinase and diphosphoinositide kinase from rat kidney cortex were studied. The enzymes were completely Mg2+-dependent. Cutscum detergent activated phosphatidylinositol kinase, but diphosphoinositide kinase was inhibited by all detergents tested. The pH optima were 7.7 for phosphatidylinositol kinase and 6.5 for diphosphoinositide kinase. On subcellular fractionation of kidney-cortex homogenates by differential centriflgation, the distribution of phosphatidylinositol kinase resembled that of the marker enzymes for brush-border, endoplasmic-reticulum and Golgi membranes. Diphosphoinositide kinase distribution resembled that of thiamin pyrophosphatase (assayed in the absence of ATP), diphosphoinositide phosphatase and triphosphoinositide phosphatase. Activities of both kinases were low in purified brush-border fragments. Diphosphoinositide kinase is probably localized in the Golgi complex.

Cyclophosphamide-induced renal damage in nude mice prevented by traditional Chinese medicine (TCM) herbal mixture LQ.

2013 ◽  
Vol 31 (15_suppl) ◽  
pp. e22210-e22210
Author(s):  
Chengyu Wu ◽  
Lei Zhang ◽  
Robert M. Hoffman
Keyword(s):  
Renal Damage ◽  
Renal Toxicity ◽  
Kidney Cortex ◽  
Thick Ascending Limb ◽  
Loop Of Henle ◽  
Outer Medulla ◽  
Herbal Mixture ◽  
Pretreated Group ◽  
Convoluted Tubules ◽  
Normal Architecture

e22210 Background: Renal damage is a dose-limiting side effects of cyclophosphamide (CYC). In the current study, we determined if a TCM herbal mixture LQ could be protective against CYC renal toxicity. Methods: Mice were treated with CYC or CYC+LQ. The histology of each organ was observed under microscopy after H&E staining. Results: The histology of the heart, liver, spleen, lung and intestine showed normal histopathological structure in all groups. The kidney of the CYC-treated mice showed toxicity including the glomeruli, the tubules, and the interstitium. The structures of the cortex in CYC pretreated group showed a disconnection between glomeruli and tubules. The ducts in the medulla were destroyed. In contrast, the kidneys in the control mice, LQ-treated mice, and CYC+LQ-treated mice showed normal architecture of the kidney cortex and medulla. In the untreated controls and the CYC+LQ-treated mice, the cortex showed normal renal corpuscles, proximal convoluted tubules, and distal convoluted tubules. The inner medulla and outer medulla all contained a thick ascending limb of the loop of Henle, and interstitial connective tissue. LQ also protected against weight loss and cachexia induced by CYC. Conclusions: TCM is a promising for combination with CYC to reduce toxicity.

Effect of benzolamide on luminal pH in proximal convoluted tubules of the rat kidney

1978 ◽  
Vol 375 (1) ◽  
pp. 39-43 ◽  
Author(s):  
F. Lang ◽  
P. Quehenberger ◽  
R. Greger ◽  
H. Oberleithner
Keyword(s):  
Rat Kidney ◽  
Luminal Ph ◽  
Convoluted Tubules ◽  
Proximal Convoluted Tubules
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