Enhanced transcription of metallothionein genes in rat kidney: effect of uninephrectomy and compensatory renal growth

1995 ◽  
Vol 268 (4) ◽  
pp. F643-F650 ◽  
Author(s):  
R. K. Zalups ◽  
J. Fraser ◽  
J. Koropatnick
Keyword(s):  
Renal Cortex ◽  
Rat Kidney ◽  
Hepatic Tissue ◽  
Renal Growth ◽  
Outer Medulla ◽  
Compensatory Renal Growth ◽  
Intracellular Regulation ◽  
Outer Stripe ◽  
Remnant Kidney

Metallothioneins (MTs) have been implicated in the intracellular regulation of essential metals in eukaryotic cells, and increased expression of MT genes has been demonstrated during the growth and proliferation of cells. To explore the expression of MT in somatic cells undergoing growth (hypertrophy) in the kidney in situ, we measured the rates of transcription of the genes for MT-1 and MT-2, measured the levels of mRNA for MT-1 and MT-2, and measured the concentration of MT-1 and MT-2 protein in samples of renal (and hepatic) tissue from uninephrectomized (NPX) and sham-operated (SO) rats 15 days after surgery. The rates of transcription of the genes for MT-1 and MT-2 were found to be enhanced significantly in the remnant renal mass, particularly in the cortex and outer stripe of the outer medulla, and in the liver, after uninephrectomy and after 15 days allowing for compensatory renal growth. Increased accumulation of mRNA for MT-1 and MT-2 also occurred in the cortex and outer stripe of the outer medulla of the remnant kidney and in the liver in the NPX rats. Increased concentration of MT-1 and MT-2 protein (measured by radioimmunoassay), at the level of the whole kidney, renal cortex, and liver, was another feature detected in rats after uninephrectomy and 15 days of compensatory renal growth. These findings indicate that compensatory renal growth in response to uninephrectomy is associated with the induction of the expression of MT genes in the renal cortex and outer stripe of the outer medulla, as well as in the liver.(ABSTRACT TRUNCATED AT 250 WORDS)

Freezing point depression of rat kidney slices during water diuresis and antidiuresis

1960 ◽  
Vol 199 (5) ◽  
pp. 915-918 ◽  
Author(s):  
George A. Bray
Keyword(s):  
Pressure Gradient ◽  
Osmotic Pressure ◽  
Freezing Point ◽  
Rat Kidney ◽  
Freezing Point Depression ◽  
Water Diuresis ◽  
Outer Medulla ◽  
Kidney Slices ◽  
Outer Stripe ◽  
Osmotic Pressure Gradient

The freezing point depression of slices of rat kidney removed during water diuresis or antidiuresis has been investigated with a microcryoscopic method. The osmotic pressure gradient in the inner medulla first demonstrated by Wirz has been confirmed. The inner medulla was found to be hypertonic to plasma during water diuresis. Hypotonic tubules were present throughout the cortex and outer stripe of the outer medulla.

Distribution and oligomeric association of splice forms of Na+-K+-ATPase regulatory γ-subunit in rat kidney

2002 ◽  
Vol 282 (3) ◽  
pp. F393-F407 ◽  
Author(s):  
Elena Arystarkhova ◽  
Randall K. Wetzel ◽  
Kathleen J. Sweadner
Keyword(s):  
Splice Variants ◽  
Rat Kidney ◽  
Thick Ascending Limb ◽  
Outer Medulla ◽  
Α Subunit ◽  
Proximal Tubule Cells ◽  
Γ Subunit ◽  
Outer Stripe ◽  
A Minor ◽  
Splice Forms

Renal Na+-K+-ATPase is associated with the γ-subunit (FXYD2), a single-span membrane protein that modifies ATPase properties. There are two splice variants with different amino termini, γa and γb. Both were found in the inner stripe of the outer medulla in the thick ascending limb. Coimmunoprecipitation with each other and the α-subunit indicated that they were associated in macromolecular complexes. Association was controlled by ligands that affect Na+-K+-ATPase conformation. In the cortex, the proportion of the γb-subunit was markedly lower, and the γa-subunit predominated in isolated proximal tubule cells. By immunofluorescence, the γb-subunit was detected in the superficial cortex only in the distal convoluted tubule and connecting tubule, which are rich in Na+-K+-ATPase but comprise a minor fraction of cortex mass. In the outer stripe of the outer medulla and for a short distance in the deep cortex, the thick ascending limb predominantly expressed the γb-subunit. Because different mechanisms maintain and regulate Na+ homeostasis in different nephron segments, the splice forms of the γ-subunit may have evolved to control the renal Na+ pump through pump properties, gene expression, or both.

Localization of angiotensin II type 1 receptor subtype mRNA in rat kidney

1995 ◽  
Vol 268 (2) ◽  
pp. F220-F226 ◽  
Author(s):  
D. P. Healy ◽  
M. Q. Ye ◽  
M. Troyanovskaya
Keyword(s):  
In Situ Hybridization ◽  
Rat Kidney ◽  
At1 Receptor ◽  
Receptor Subtypes ◽  
Mrna Levels ◽  
Ang Ii ◽  
Outer Medulla ◽  
Vasa Recta

The physiological effects of angiotensin II (ANG II) on the kidney are mediated primarily by the ANG II type 1 (AT1) receptor. Two highly similar AT1 receptor subtypes have been identified in the rat by molecular cloning techniques, namely AT1A and AT1B. The intrarenal localization of the AT1A and AT1B receptor subtypes has not been studied by hybridization methods with subtype-specific receptor probes. Using radiolabeled probes from the 3' noncoding region of the AT1A and AT1B cDNAs, we localized AT1 mRNA in rat kidney by in situ hybridization. Specificity of the 3' noncoding region probes was tested by Northern blot and solution hybridization methods. AT1A mRNA levels were highest in the liver, kidney, and adrenal. In contrast, AT1B mRNA levels were highest in the adrenal and pituitary and low in kidney. Autoradiographic localization of 125I-[Sar1,Ile8]ANG II binding indicated that the highest levels of AT1 receptors were found in glomeruli and vascular elements. In situ hybridization with a nonselective AT1 receptor riboprobe indicated that the highest levels of AT1 mRNA were in the outer medullary vasa recta and cortical glomeruli with additional diffuse labeling of the cortex and outer medulla, consistent with labeling of tubular elements. In contrast, in situ hybridization with the AT1 subtype selective probes revealed that AT1A receptor mRNA was primarily localized to the vasa recta and diffusely to the outer stripe of the outer medulla and the renal cortex.(ABSTRACT TRUNCATED AT 250 WORDS)

Cloning, embryonic expression, and alternative splicing of a murine kidney-specific Na-K-Cl cotransporter

1995 ◽  
Vol 269 (3) ◽  
pp. F405-F418 ◽  
Author(s):  
P. Igarashi ◽  
G. B. Vanden Heuvel ◽  
J. A. Payne ◽  
B. Forbush
Keyword(s):  
In Situ Hybridization ◽  
Alternative Splicing ◽  
Protein Kinase ◽  
Thick Ascending Limb ◽  
Outer Medulla ◽  
Donor And Acceptor ◽  
Outer Stripe ◽  
Dependent Protein ◽  
Isoform B

A full-length cDNA encoding the murine renal Na-K-Cl cotransporter (NKCC2) was cloned using library screening and anchored polymerase chain reaction. The deduced protein sequence contained 1,095 amino acids and was 93.5% identical to rabbit NKCC2 and 97.6% identical to rat BSC1. Two potential sites of phosphorylation by adenosine 3',5'-cyclic monophosphate-dependent protein kinase and seven potential sites of phosphorylation by protein kinase C, which were previously identified in the rabbit and rat sequences, were phylogenetically conserved in the mouse. The expression of NKCC2 in the mouse was examined with Northern blot analysis and in situ hybridization. Expression of NKCC2 was kidney specific in both adult and embryonic mice. In the developing metanephros, NKCC2 was induced at 14.5 days post coitus and was expressed in distal limbs of immature loops of Henle but was absent from the ureteric bud, S-shaped bodies, and earlier nephrogenic structures. Similar to the rabbit, isoforms of NKCC2 that differed in the sequence of a 96-bp segment were identified in the mouse. In situ hybridization revealed that the isoforms exhibited different patterns of expression in the mature thick ascending limb of the loop of Henle as follows: isoform F was most highly expressed in the inner stripe of outer medulla, isoform A was most highly expressed in the outer stripe of the outer medulla, and isoform B was most highly expressed in the cortical thick ascending limb. To verify that the isoforms were generated by alternative splicing of mutually exclusive cassette exons, genomic clones encoding murine NKCC2 were characterized. Cassette exons were identified that corresponded to each of the three isoforms and were flanked by consensus splice donor and acceptor sequences.

Immunolocalization of electroneutral Na-HCO3 − cotransporter in rat kidney

2000 ◽  
Vol 279 (5) ◽  
pp. F901-F909 ◽  
Author(s):  
Henrik Vorum ◽  
Tae-Hwan Kwon ◽  
Christiaan Fulton ◽  
Brian Simonsen ◽  
Inyeong Choi ◽  
...  
Keyword(s):  
Plasma Membranes ◽  
Collecting Duct ◽  
Rat Kidney ◽  
Electron Microscopic Level ◽  
Thick Ascending Limb ◽  
Intercalated Cells ◽  
Electron Microscopic ◽  
Outer Medulla ◽  
Outer Stripe ◽  
Medullary Collecting Duct

An electroneutral Na-HCO3 − cotransporter (NBCN1) was recently cloned, and Northern blot analyses indicated its expression in rat kidney. In this study, we determined the cellular and subcellular localization of NBCN1 in the rat kidney at the light and electron microscopic level. A peptide-derived antibody was raised against the COOH-terminal amino acids of NBCN1. The affinity-purified antibody specifically recognized one band, ∼180 kDa, in rat kidney membranes. Peptide- N-glycosidase F deglycosylation reduced the band to ∼140 kDa. Immunoblotting of membrane fractions from different kidney regions demonstrated strong signals in the inner stripe of the outer medulla (ISOM), weaker signals in the outer stripe of the outer medulla and inner medulla, and no labeling in cortex. Immunocytochemistry demonstrated that NBCN1 immunolabeling was exclusively observed in the basolateral domains of thick ascending limb (TAL) cells in the outer medulla (strongest in ISOM) but not in the cortex. In addition, collecting duct intercalated cells in the ISOM and in the inner medulla also exhibited NBCN1 immunolabeling. Immunoelectron microscopy demonstrated that NBCN1 labeling was confined to the basolateral plasma membranes of TAL and collecting duct type A intercalated cells. Immunolabeling controls were negative. By using 2,7-bis-carboxyethyl-5,6-caboxyfluorescein, intracellular pH transients were measured in kidney slices from ISOM and from mid-inner medulla. The results revealed DIDS-sensitive, Na- and HCO3 −-dependent net acid extrusion only in the ISOM but not in mid-inner medulla, which is consistent with the immunolocalization of NBCN1. The localization of NBCN1 in medullary TAL cells and medullary collecting duct intercalated cells suggests that NBCN1 may be important for electroneutral basolateral HCO3 − transport in these cells.

Cell-specific regulation of cytosolic aspartate aminotransferase by glucocorticoids in the rat kidney

1993 ◽  
Vol 265 (5) ◽  
pp. C1298-C1305 ◽  
Author(s):  
S. Feilleux-Duche ◽  
M. Garlatti ◽  
M. Aggerbeck ◽  
M. Poyard ◽  
J. Bouguet ◽  
...  
Keyword(s):  
Aspartate Aminotransferase ◽  
Hormonal Regulation ◽  
Renal Cortex ◽  
Rat Kidney ◽  
Thick Ascending Limb ◽  
Outer Medulla ◽  
Maximal Increase ◽  
Basal Expression ◽  
Specific Increase ◽  
Specific Regulation

The basal expression and hormonal regulation of cytosolic aspartate aminotransferase (cAspAT) were investigated in the rat kidney. In adrenalectomized animals, the basal activity was highest in the renal cortex and in the inner stripe of the outer medulla (0.1-0.15 U/mg protein). The glucocorticoid analogue dexamethasone increased cAspAT activity about twofold in the cortex and in the inner stripe of the outer medulla but not in the papilla. A half-maximal increase in the activity was achieved at doses of approximately 5 micrograms/100 g body wt. The mineralocorticoid aldosterone did not modify the cAspAT activity. The cell specificity of the hormonal regulation was analyzed by in situ hybridization. In untreated adrenalectomized rats, a cAspAT cRNA probe labeled mainly the inner stripe of the outer medulla. After dexamethasone or hydrocortisone treatment, labeling was uniformly increased in this part of the medulla and was heterogeneously increased in the renal cortex. The specific increase in labeling within the cortex was shown to be confined to the distal convoluted tubule and the thick ascending limb. We conclude that, in addition to widespread basal expression, cAspAT is regulated by glucocorticoids in a highly cell-specific manner in the renal cortex. The enzyme may thus participate in the increased energy metabolism elicited by these hormones in these cells.

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.

Abstract P284: Angiotensin II Upregulates Cytochrome-450 4A Expression in Rat Kidney Through Type 1 Receptor

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Wanting Wang ◽  
Rong Rong ◽  
Osamu Ito ◽  
Yoshiko Ogawa ◽  
Yoshikazu Muroya ◽  
...  
Keyword(s):  
Renal Cortex ◽  
Urinary Albumin Excretion ◽  
Rat Kidney ◽  
At1 Receptor ◽  
Urinary Albumin ◽  
High Dose ◽  
At2 Receptor ◽  
Ang Ii ◽  
Outer Medulla

20-hydroxyeicosatetraenoic acids (20-HETE) is a cytochrome P-450 (CYP) 4A-dependent metabolite of arachidonic acid and regulates vascular tone and renal tubular function. Previous studies showed that angiotensin II (Ang II) stimulated the renal CYP activity and 20-HETE production through the Ang II type 1 (AT1) receptor and that the Ang II-increased the 20-HETE was linked to the Ang II type 2(AT2) receptor. Thus, the study was designed to clarify the role of Ang II in CYP4A isoforms expression in the rat kidney. Male Sprague-Dawley rats were infused Ang II at low dose (AL, 0.17mg/kg/min, sc) and high dose (AH, 0.70mg/kg/day, sc) by using osmotic mini pump, with or without AT1 receptor blocker candesartan (1 and 3mg/kg/day, po) for 1 week. The protein expression of CYP4A isoforms, AT1 receptor and AT2 receptor in the renal cortex, outer medulla, and inner medulla was examined by immunoblot analysis. The mRNA expression of CYP4A isoforms was examined by reverse transcription and polymerase chain reaction (RT-PCR). Ang II at high dose increased systolic blood pressure (control, 109±2; AH, 164±8 mmHg, p<0.01), creatinine (control, 0.24±0.00; AH, 0.29±0.01 mg/dl, p<0.01) and urinary albumin excretion (control, 20.3±5.9; AH, 2398.6±303.6 μg/mg creatinine, p<0.01). In the control group, the CYP4A1, 4A2, and 4A8 proteins were highly expressed in the renal cortex, lowly expressed in the outer medulla, barely detected in the inner medulla. The AT1 receptor was expressed in kidney sections; highly in the outer and inner medulla, the AT2 receptor was only detected in the outer medulla. Ang II dose-dependently increased all CYP4A isoform proteins in the renal cortex and outer medulla (CYP4A1, 24% and 222%; CYP4A2, by 51% and 258%; CYP4A8, by 52% and 550%, p<0.05). Ang II also increased all CYP4A isoform mRNAs in the renal cortex and outer medulla. The candesartan treatment dose-dependently inhibited the Ang II-increased blood pressure, creatinine, urinary albumin excretion and CYP4A isoform expressions. These results indicated that Ang II increases CYP4A isoform expressions in the kidney through AT1 receptor. The Ang II-upregulated CYP4A expressions may play an important role in hypertension and renal function.

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.

Renal expression of novel Na+/H+exchanger isoform NHE8

2003 ◽  
Vol 284 (3) ◽  
pp. F467-F473 ◽  
Author(s):  
Sunita Goyal ◽  
Gregory Vanden Heuvel ◽  
Peter S. Aronson
Keyword(s):  
Proximal Tubule ◽  
Amino Acid Identity ◽  
Outer Medulla ◽  
Reading Frame ◽  
Mouse Tissues ◽  
Outer Stripe ◽  
Apical Membranes ◽  
Nhe Isoforms ◽  
Renal Expression

Although Na+/H+exchanger isoform 3 (NHE3) mediates most Na+/H+exchange in the proximal tubule, studies of NHE3/NHE2 null mice suggest residual Na+-dependent proton secretion (Choi JY, Shah M, Lee MG, Schultheis PJ, Shull GE, Muallem S, and Baum M. J Clin Invest 105: 1141–1146, 2000). To characterize additional NHE isoforms that might be expressed in the kidney, we identified the partial sequence of a novel NHE. PCR was used to define the 5′- and 3′-ends, and a cDNA encoding the complete open reading frame was amplified from mouse kidney. The predicted protein of 576 amino acids, which we have named NHE8, has 30–35% amino acid identity to known mammalian isoforms (NHE1–7) but has >50% identity to Drosophila melanogaster “NHE1,” suggesting it is the mammalian ortholog of this ancient invertebrate isoform. Northern blot of mouse tissues revealed ubiquitous expression. Western blot using anti-NHE8 antibodies demonstrated protein expression in apical membranes purified from rat renal cortex by divalent cation precipitation. In situ hybridization revealed that NHE8 message was present in both cortex and medulla. In the cortex, NHE8 was present in the majority of cortical tubules, consistent with proximal tubule (S1 and S2) localization. In the medulla, NHE8 message was most highly expressed in the proximal tubules (S3) of the outer stripe of the outer medulla. Thus NHE8 is expressed in the proximal tubule, where it may contribute to apical membrane ion transport.

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