Uptake and Subcellular Distribution of Poly-L-Aspartic Acid, a Protectant Against Aminoglycoside-Induced Nephrotoxicity, in Rat Kidney Cortex

1989 ◽  
pp. 189-192
Author(s):  
Paul M. Tulkens ◽  
Zoltan Kallay
Keyword(s):  
Aspartic Acid ◽  
Subcellular Distribution ◽  
Rat Kidney ◽  
Kidney Cortex ◽  
Rat Kidney Cortex

Subcellular distribution of renal tripeptide-releasing exopeptidases active on collagen-like sequences

1987 ◽  
Vol 252 (5) ◽  
pp. F890-F898
Author(s):  
K. J. Andersen ◽  
J. K. McDonald
Keyword(s):  
Subcellular Distribution ◽  
Microsomal Fraction ◽  
Specific Activity ◽  
Rat Kidney ◽  
Broad Band ◽  
Distribution Patterns ◽  
Kidney Cortex ◽  
Rat Kidney Cortex ◽  
Tripeptidyl Peptidase ◽  
N Terminus

The rat kidney cortex was found to contain two N-terminal exopeptidases of the tripeptidyl peptidase (TPP) class. Each required a free N-terminus to catalyze the release of collagen-related (Gly-Pro-X) "triplets." In accordance with their apparent pH optima, activities were routinely determined fluorimetrically at pH 4.0 (TPP 4) and at pH 7.0 (TPP 7) on Gly-Pro-Met-2-naphthylamide. The specific activity in both the homogenate and the classical subfractions was much greater at pH 7 than at pH 4. Subfractionation of the microsomal fraction by equilibrium banding in sucrose did not separate the TPP 4 and TPP 7 activities. The banding density (1.18 g/ml) and the distribution patterns for TPP 7 in the microsomal subfractions, and also in the subfractions of the small lysosomes in the mitochondrial-lysosomal (ML) fraction, demonstrate that TPP 7 is associated with smooth membranes. The TPP 4 and TPP 7 activities were clearly separated during subfractionation of the ML fraction. Rate sedimentation demonstrated that TPP 4 was present in the large, fast-sedimenting lysosomes (protein droplets) and in a heterogeneous broad band of smaller lysosomes. Equilibrium banding of the small lysosomes gave two distinct TPP 4-containing populations at densities 1.20 and 1.235 g/ml. Notably, dipeptidyl peptidase II (DPP II) gave identical banding densities and showed distributions very similar to TPP 4.(ABSTRACT TRUNCATED AT 250 WORDS)

SOME EFFECTS OF PHLORIZIN AND PHLORETIN ON RENAL AMINO ACID REABSORPTION IN THE DOG

1965 ◽  
Vol 43 (1) ◽  
pp. 79-87 ◽  
Author(s):  
William A. Webber
Keyword(s):  
Amino Acid ◽  
Aspartic Acid ◽  
Rat Kidney ◽  
Kidney Cortex ◽  
Rat Kidney Cortex ◽  
Site Of Action ◽  
Proximal Tubular ◽  
Amino Acid Levels ◽  
Amino Acid Concentrations

The effects of phlorizin and phloretin on amino acid reabsorption were studied using clearance techniques in dogs. At endogenous plasma amino acid concentrations no effects were demonstrable. At elevated amino acid levels phlorizin depressed the reabsorption of L-aspartic acid and L-lysine. Phloretin depressed the reabsorption of L-aspartic acid but had a slight enhancing effect on that of L-lysine. No definite effects were observed on L-alanine or glycine reabsorption. These results are not predictable from the observations of other workers that in the in vitro rat kidney cortex phlorizin increases amino acid concentrating ability while phloretin depresses it. Our results are not, however, incompatible with the in vitro observations since it is theoretically possible for an agent to enhance the concentrating ability of kidney cortex, and either depress or increase tubular reabsorption, depending on whether the predominant site of action is on the luminal or basal side of the proximal tubular cells.

Subcellular distribution and guanine nucleotide dependency of COOH-terminal methylation in kidney cortex

1993 ◽  
Vol 265 (2) ◽  
pp. F316-F322
Author(s):  
D. Gingras ◽  
D. Boivin ◽  
R. Beliveau
Keyword(s):  
Subcellular Distribution ◽  
Plasma Membranes ◽  
Rat Kidney ◽  
Wide Distribution ◽  
Cysteine Residue ◽  
Kidney Cortex ◽  
Rat Kidney Cortex ◽  
Carboxyl Methyltransferase ◽  
Exogenous Substrate ◽  
Gamma S

The subcellular distribution of COOH-terminal carboxyl methyltransferase and methylated substrates was studied in purified brush-border and basolateral plasma membranes, as well as in crude intracellular membranes and the cytosolic fraction isolated from rat kidney cortex. The three membrane fractions showed intrinsic carboxyl methylation of 21- to 23-kDa proteins, whereas 18- and 41-kDa methylated proteins were observed in the cytosol. In contrast, methylation activities toward N-acetyl-S-trans,trans-farnesyl-L-cysteine (AFC), a synthetic farnesylated substrate, were found to be strictly associated with membranes, with no detectable level of activity in the cytosol. Methylation of all membrane-associated substrates was inhibited by AFC but remained unaffected by TS-isoD-YSKY, a synthetic isopeptide recognized by L-isoaspartyl methyltransferase, suggesting that the membrane-associated substrates were methylated on a COOH-terminal isoprenylated cysteine residue. The membrane-associated methylated proteins were tightly bound to the membranes as reflected by their extraction with 3-[(3-cholamidopropyl)-dimethylammonio]-1-propanesulfonate but not with 1 M NaCl or 2 M urea. The nonhydrolyzable analogues of GTP and GDP, guanosine 5'-O-(3-thiotriphosphate) (GTP gamma S) and guanosine 5'-O-(2-thiodiphosphate) (GDP beta S), markedly increased the methylation of the 21- to 23-kDa substrates, whereas ATP gamma S and ADP beta S were without effect. This effect of guanine nucleotides was restricted to endogenous 21- to 23-kDa substrates with no stimulation of methylation of the exogenous substrate, AFC. Our results show a wide distribution of both COOH-terminal protein carboxyl methyltransferase activities and associated methylated substrates in the kidney cortex.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Increase of Na/Pi-cotransport encoding mRNA in response to low Pi diet in rat kidney cortex.

1994 ◽  
Vol 269 (9) ◽  
pp. 6637-6639
Author(s):  
A. Werner ◽  
S.A. Kempson ◽  
J. Biber ◽  
H. Murer
Keyword(s):  
Rat Kidney ◽  
Kidney Cortex ◽  
Rat Kidney Cortex

Cytochrome P-450K of rat kidney cortex microsomes: Further studies on its interaction with fatty acids

1973 ◽  
Vol 158 (2) ◽  
pp. 597-604 ◽  
Author(s):  
Åke Ellin ◽  
Sten Orrenius ◽  
Åke Pilotti ◽  
Carl-Gunnar Swahn
Keyword(s):  
Fatty Acids ◽  
Rat Kidney ◽  
Kidney Cortex ◽  
Rat Kidney Cortex

scholarly journals Studies on the orientation of brush-border membrane vesicles

1978 ◽  
Vol 172 (1) ◽  
pp. 57-62 ◽  
Author(s):  
W Haase ◽  
A Schäfer ◽  
H Murer ◽  
R Kinne
Keyword(s):  
Brush Border ◽  
Brush Border Membrane ◽  
Rat Kidney ◽  
Freeze Fracture ◽  
Membrane Vesicles ◽  
Brush Border Membrane Vesicles ◽  
Immunological Methods ◽  
Kidney Cortex ◽  
Asymmetric Distribution ◽  
Rat Kidney Cortex

Orientation of rat renal and intestinal brush-border membrane vesicles was studied with two independent methods: electron-microscopic freeze-fracture technique and immunological methods. With the freeze-fracture technique a distinct asymmetric distribution of particles on the two membrane fracture faces was demonstrated; this was used as a criterion for orientation of the isolated membrane vesicles. For the immunological approach the accessibility or inaccessibility of aminopeptidase M localized on the outer surface of the cell membrane to antibodies was used. With both methods we showed that the brush-border membrane vesicles isolated from rat kidney cortex and from rat small intestine for transport studies are predominantly orientated right-side out.

Endogenous Kallikrein Inhibitor in Rat Kidney Cortex-Effect of Glucocorticoid Administration

1986 ◽  
pp. 361-365 ◽  
Author(s):  
Kodo Ito ◽  
Kenichi Yamada ◽  
Setsuko Yoshida ◽  
Keiji Hasunuma ◽  
Yasushi Tamura ◽  
...  
Keyword(s):  
Rat Kidney ◽  
Kidney Cortex ◽  
Rat Kidney Cortex ◽  
Kallikrein Inhibitor ◽  
Glucocorticoid Administration
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