Intracellular Localization of Cyclosporin A in the Rat Kidney

1989 ◽  
pp. 325-330
Author(s):  
Miloslav Dobrota ◽  
Julian R. Louis
Keyword(s):  
Cyclosporin A ◽  
Rat Kidney ◽  
Intracellular Localization

The Morphology of the Rat Kidney Following Folic Acid Administration

1970 ◽  
Vol 28 ◽  
pp. 200-201
Author(s):  
Aline Byrnes ◽  
Elsa E. Ramos ◽  
Minoru Suzuki ◽  
E.D. Mayfield
Keyword(s):  
Folic Acid ◽  
De Novo ◽  
Specific Activity ◽  
Rat Kidney ◽  
Present Report ◽  
Intracellular Localization ◽  
Male Rats ◽  
Renal Hypertrophy ◽  
Electron Microscopic ◽  
Biochemical Alterations

Renal hypertrophy was induced in 100 g male rats by the injection of 250 mg folic acid (FA) dissolved in 0.3 M NaHCO3/kg body weight (i.v.). Preliminary studies of the biochemical alterations in ribonucleic acid (RNA) metabolism of the renal tissue have been reported recently (1). They are: RNA content and concentration, orotic acid-c14 incorporation into RNA and acid soluble nucleotide pool, intracellular localization of the newly synthesized RNA, and the specific activity of enzymes of the de novo pyrimidine biosynthesis pathway. The present report describes the light and electron microscopic observations in these animals. For light microscopy, kidney slices were fixed in formalin, embedded, sectioned, and stained with H & E and PAS.

scholarly journals MITOCHONDRIAL LOCALIZATION OF OXIDATIVE ENZYMES: STAINING RESULTS WITH TWO TETRAZOLIUM SALTS

1961 ◽  
Vol 9 (1) ◽  
pp. 47-61 ◽  
Author(s):  
Alex B. Novikoff ◽  
Woo-Yung Shin ◽  
Joan Drucker
Keyword(s):  
Rat Kidney ◽  
Intracellular Localization ◽  
Oxidative Enzymes ◽  
Mitochondrial Morphology ◽  
Mitochondrial Localization ◽  
Enzyme Localization ◽  
Aqueous Interfaces ◽  
Physicochemical Factors ◽  
Lipofuscin Granules ◽  
In Cells

A comparison is made of the staining results obtained with Nitro-BT and MTT-Co++ as acceptors when DPNH is the substrate in frozen sections of cold formol-calcium-fixed rat kidney (normal and following ligation of the blood vessels) and human liver containing lipofuscin granules. The kidney results are evaluated in terms of mitochondrial morphology seen after classical mitochondrial stains and in electron micrographs. It is concluded that, except for formazan deposition on lipid-aqueous interfaces, Nitro-BT staining indicates the intracellular localization of oxidative enzymes, at least at the level of light microscopy. In contrast, the use of MTT-Co++ is not reliable for such intracellular localizations. The deposition of the formazan of MTT-Co++ is determined in large part by physicochemical factors other than enzyme localization. Despite marked abnormalities of the mitochondria in cells of the ligated kidney, MTT-Co++ formazan is generally deposited in the same dotlike fashion as in cells of normal kidney.

scholarly journals Synthesis of [1,2-3H2]cholecalciferol and metabolism of [4-14C,1,2-3H2]- and [4-14C,1-3H]-cholecalciferol in rachitic rats and chicks

1971 ◽  
Vol 121 (4) ◽  
pp. 673-682 ◽  
Author(s):  
D. E. M. Lawson ◽  
B. Pelc ◽  
P. A. Bell ◽  
P. W. Wilson ◽  
E. Kodicek
Keyword(s):  
Vitamin D ◽  
Substance P ◽  
Rat Kidney ◽  
Intracellular Localization ◽  
Specific Radioactivity ◽  
Experimental Period ◽  
Time Interval ◽  
High Concentration ◽  
Very High ◽  
25 Hydroxycholecalciferol

[1,2-3H2]Cholecalciferol has been synthesized with a specific radioactivity of 508mCi/mmol by using tristriphenylphosphinerhodium chloride, the homogeneous hydrogen catalyst. With doses of 125ng (5i.u.) of [4-14C,1-3H2]cholecalciferol the tissue distribution in rachitic rats of cholecalciferol and its metabolites (25-hydroxycholecalciferol and peak P material) was similar to that found in chicken with 500ng doses of the double-labelled vitamin. The only exceptions were rat kidney, with a very high concentration of vitamin D, and rat blood, with a higher proportion of peak P material, containing a substance formed from vitamin D with the loss of hydrogen from C-1. Substance P formed from [4-14C,1,2-3H2]cholecalciferol retained 36% of 3H, the amount expected from its distribution between C-1 and C-2, the 3H at C-1 being lost. 25-Hydroxycholecalciferol does not seem to have any specific intracellular localization within the intestine of rachitic chicks. The 3H-deficient substance P was present in the intestine and bone 1h after a dose of vitamin D and 30min after 25-hydroxycholecalciferol. There was very little 25-hydroxycholecalciferol in intestine at any time-interval, but bone and blood continued to take it up over the 8h experimental period. It is suggested that the intestinal 3H-deficient substance P originates from outside this tissue. The polar metabolite found in blood and which has retained its 3H at C-1 is not a precursor of the intestinal 3H-deficient substance P.

Dietary Glycine and Renal Denervation Prevents Cyclosporin A-Induced Hydroxyl Radical Production in Rat Kidney

1999 ◽  
Vol 56 (3) ◽  
pp. 455-463 ◽  
Author(s):  
Zhi Zhong ◽  
Henry D. Connor ◽  
Ming Yin ◽  
Nicholas Moss ◽  
Ronald P. Mason ◽  
...  
Keyword(s):  
Hydroxyl Radical ◽  
Cyclosporin A ◽  
Renal Denervation ◽  
Rat Kidney ◽  
Radical Production

scholarly journals The C-terminus of connexin43 adopts different conformations in the Golgi and gap junction as detected with structure-specific antibodies

2007 ◽  
Vol 408 (3) ◽  
pp. 375-385 ◽  
Author(s):  
Gina E. Sosinsky ◽  
Joell L. Solan ◽  
Guido M. Gaietta ◽  
Lucy Ngan ◽  
Grace J. Lee ◽  
...  
Keyword(s):  
Gap Junction ◽  
Tertiary Structure ◽  
Mutational Analysis ◽  
Peptide Mapping ◽  
Rat Kidney ◽  
Intracellular Localization ◽  
Protein Protein Interaction ◽  
Binding Domains ◽  
C Terminus ◽  
Junction Protein

The C-terminus of the most abundant and best-studied gap-junction protein, connexin43, contains multiple phosphorylation sites and protein-binding domains that are involved in regulation of connexin trafficking and channel gating. It is well-documented that SDS/PAGE of NRK (normal rat kidney) cell lysates reveals at least three connexin43-specific bands (P0, P1 and P2). P1 and P2 are phosphorylated on multiple, unidentified serine residues and are found primarily in gap-junction plaques. In the present study we prepared monoclonal antibodies against a peptide representing the last 23 residues at the C-terminus of connexin43. Immunofluorescence studies showed that one antibody (designated CT1) bound primarily to connexin43 present in the Golgi apparatus, whereas the other antibody (designated IF1) labelled predominately connexin43 present in gap junctions. CT1 immunoprecipitates predominantly the P0 form whereas IF1 recognized all three bands. Peptide mapping, mutational analysis and protein–protein interaction experiments revealed that unphosphorylated Ser364 and/or Ser365 are critical for CT1 binding. The IF1 paratope binds to residues Pro375–Asp379 and requires Pro375 and Pro377. These proline residues are also necessary for ZO-1 interaction. These studies indicate that the conformation of Ser364/Ser365 is important for intracellular localization, whereas the tertiary structure of Pro375–Asp379 is essential in targeting and regulation of gap junctional connexin43.

scholarly journals Inhibition of calbindin D28K expression by cyclosporin A in rat kidney: the possible pathogenesis of cyclosporin A-induced hypercalciuria.

1998 ◽  
Vol 9 (8) ◽  
pp. 1416-1426
Author(s):  
C W Yang ◽  
J Kim ◽  
Y H Kim ◽  
J H Cha ◽  
S Y Mim ◽  
...  
Keyword(s):  
Cyclosporin A ◽  
Serum Calcium ◽  
Protein Level ◽  
Rat Kidney ◽  
Urinary Calcium ◽  
Calcium Handling ◽  
Calcium Excretion ◽  
Urine Calcium ◽  
Calbindin D28k ◽  
Urine Calcium Excretion

A recent study by Steiner et al. (Biochem Pharmacol 51: 253-258, 1996) demonstrated a decreased calbindin D28K expression in the kidneys of cyclosporin A (CsA)-treated rats. To evaluate the association of renal calcium handling with calbindin D28K expression in CsA-treated rats, two separate experiments (vehicle [VH] versus CsA groups, 1,25-dihydroxyvitamin D3 [VitD] versus VitD + CsA groups) were done simultaneously. CsA (25 mg/kg per d, subcutaneously) and VitD (0.5 microg/kg per d, subcutaneously) were given for 7 d. The CsA group showed decreased serum calcium, increased urine calcium excretion, and decreased calbindin D28K protein level and immunoreactivity compared with the VH group. The VitD + CsA treatment decreased serum calcium, increased urine calcium excretion, and decreased calbindin D28K protein level and immunoreactivity compared with the VitD alone. CsA treatment did not affect the serum parathyroid hormone and VitD levels. This study demonstrates an association of calbindin D28K expression with the urinary calcium excretion in CsA-treated rats, and suggests that decreased calbindin D28K expression may play a role in renal calcium wasting.

scholarly journals Intracellular localization of human Ins(1,3,4,5,6)P5 2-kinase

2007 ◽  
Vol 408 (3) ◽  
pp. 335-345 ◽  
Author(s):  
Maria A. Brehm ◽  
Tobias M. H. Schenk ◽  
Xuefei Zhou ◽  
Werner Fanick ◽  
Hongying Lin ◽  
...  
Keyword(s):  
Nuclear Export ◽  
Fluorescent Protein ◽  
Rat Kidney ◽  
Intracellular Localization ◽  
Stress Granules ◽  
Site Directed Mutagenesis ◽  
Normal Rat ◽  
High Concentrations ◽  
Green Fluorescent ◽  
Sites Of Action

InsP6 is an intracellular signal with several proposed functions that is synthesized by IP5K [Ins(1,3,4,5,6)P5 2-kinase]. In the present study, we overexpressed EGFP (enhanced green fluorescent protein)–IP5K fusion proteins in NRK (normal rat kidney), COS7 and H1299 cells. The results indicate that there is spatial microheterogeneity in the intracellular localization of IP5K that could also be confirmed for the endogenous enzyme. This may facilitate changes in InsP6 levels at its sites of action. For example, overexpressed IP5K showed a structured organization within the nucleus. The kinase was preferentially localized in euchromatin and nucleoli, and co-localized with mRNA. In the cytoplasm, the overexpressed IP5K showed locally high concentrations in discrete foci. The latter were attributed to stress granules by using mRNA, PABP [poly(A)-binding protein] and TIAR (TIA-1-related protein) as markers. The incidence of stress granules, in which IP5K remained highly concentrated, was further increased by puromycin treatment. Using FRAP (fluorescence recovery after photobleaching) we established that IP5K was actively transported into the nucleus. By site-directed mutagenesis we identified a nuclear import signal and a peptide segment mediating the nuclear export of IP5K.

Interaction of rat kidney P-glycoprotein with a urinary component and various drugs including cyclosporin A

1994 ◽  
Vol 266 (1) ◽  
pp. F66-F75
Author(s):  
J. H. Charuk ◽  
T. W. Loo ◽  
D. M. Clarke ◽  
R. A. Reithmeier
Keyword(s):  
Cyclosporin A ◽  
Rat Kidney ◽  
Multidrug Resistant ◽  
Multidrug Resistance Gene ◽  
Drug Induced ◽  
Rat Urine ◽  
P Glycoprotein ◽  
Class 1 ◽  
Rabbit Polyclonal Antibody ◽  
Endogenous Substrate

The interaction of rat renal P-glycoprotein with various drugs and a hydrophobic component found in rat urine was studied to gain an understanding of both its transport function in kidney and its potential role in drug secretion and drug-induced nephrotoxicity. Rat kidney brush-border membranes (BBM) were photolabeled with [3H]azidopine, a calcium-channel blocker that covalently labeles P-glycoprotein. P-glycoprotein was immunoprecipitated with a rabbit polyclonal antibody against the human MDR1 protein (multidrug resistance gene class 1). The amount of [3H]azidopine incorporated into P-glycoprotein was quantitated following gel electrophoresis and fluorography. Photolabeling inhibition assays were conducted with a panel of drugs known to interact with P-glycoprotein in multidrug-resistant cells. Verapamil or quinidine [half-maximal inhibition constant (K0.5) = 1 microM], vinblastine (K0.5 = 3 microM), and doxorubicin or daunomycin (K0.5 = 10 microM) all blocked [3H]azidopine photolabeling of renal P-glycoprotein. Of the drugs tested, the immunosuppressant drug, cyclosporin A, interacted with kidney P-glycoprotein with the highest affinity (K0.5 = 50 nM). However, the cardiac glycoside, digoxin, failed to inhibit P-glycoprotein photolabeling. A hydrophobic rat urine extract prepared by reverse-phase chromatography also blocked photolabeling of renal P-glycoprotein. Our current hypothesis is that various drugs may inhibit urinary excretion of an endogenous substrate by virtue of their ability to bind with high affinity to P-glycoprotein. A hypothesis of drug-induced nephrotoxicity based on the interaction of various compounds like cyclosporin A with P-glycoprotein is presented.

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