Cellular Osmoregulation in Kidney Medulla

1998 ◽  
pp. 169-184 ◽  
Author(s):  
F.-X. Beck ◽  
W.G. Guder ◽  
M. Schmolke
Keyword(s):  
Kidney Medulla

scholarly journals Structural differences and the presence of unsubstituted amino groups in heparan sulphates from different tissues and species

1997 ◽  
Vol 322 (2) ◽  
pp. 499-506 ◽  
Author(s):  
Toshihiko TOIDA ◽  
Hisao YOSHIDA ◽  
Hidenao TOYODA ◽  
Ichiro KOSHIISHI ◽  
Toshio IMANARI ◽  
...  
Keyword(s):  
Acid Content ◽  
Heparan Sulphate ◽  
Kidney Medulla ◽  
Isolation And Characterization ◽  
Iduronic Acid ◽  
Structural Differences ◽  
Liver And Kidney ◽  
High Degree ◽  
Different Tissues

This study presents a comparison of heparan sulphate chains isolated from various porcine and bovine tissues. 1H-NMR spectroscopy (500 MHz) was applied for structural and compositional studies on intact heparan sulphate chains. After enzymic digestion of heparan sulphate using heparin lyase I (EC 4.2.2.7) II and III (EC 4.2.2.8), the compositions of unsaturated disaccharides obtained were determined by analytical capillary electrophoresis. Correlations between the N-sulphated glucosamine residues and O-sulphation and between iduronic acid content and total sulphation were discovered using the data obtained by NMR and disaccharide analysis. Heparan sulphate chains could be classified into two groups based on the sulphation degree and the iduronic acid content. Heparan sulphate chains with a high degree of sulphation possessed also a significant number of iduronic acid residues and were isolated exclusively from porcine brain, liver and kidney medulla. The presence and amount of N-unsubstituted glucosamine residues (GlcNp) was established in all of the heparan sulphates examined. The structural context in which this residue occurs was demonstrated to be: high sulphation domain → 4)-β-d-GlcAp-(1 → 4)-α-d-GlcNp-(1 → 4)-β-d-GlcAp-(1 → low sulphation domain (where GlcNp is 2-amino-2-deoxyglucopyranose, and GlcAp is glucopyranosyluronic acid), based on the isolation and characterization of a novel, heparin lyase III-derived, GlcNp containing tetrasaccharide and hexasaccharide. The results presented suggest that structural differences may play a role in important biological events controlled by heparan sulphate in different tissues.

The fate and uptake of murine epidermal growth factor in the sheep

1989 ◽  
Vol 123 (1) ◽  
pp. 121-130 ◽  
Author(s):  
L. M. Tyson ◽  
C. A. Browne ◽  
G. Jenkin ◽  
G. D. Thorburn
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Bolus Injection ◽  
Kidney Cortex ◽  
Kidney Medulla ◽  
Body Tissues ◽  
Rapid Fall ◽  
Epidermal Growth ◽  
Slow Rise ◽  
Initial Bolus

ABSTRACT 125I-Labelled murine epidermal growth factor (EGF) was injected or infused into conscious ewes through the jugular vein. Its disappearance from the circulation and the pattern of its distribution in other body tissues and compartments were observed. Single bolus injections of 125I-labelled EGF resulted in a transient peak of radioactive EGF in the circulation which occurred within 1 min of the injection. This was followed by a very rapid fall in radioactivity in the plasma (t½ ∼ 1 min) and the gradual appearance of 125I-labelled EGF in the urine. Immunoprecipitable 125I-labelled EGF could be detected in urine within 5 min of the start of the experiment. 125I-Labelled EGF accumulated in the urine for several hours following the injection, although with increasing time a substantial amount of non-immunoprecipitable iodide was also found. The rate of disappearance of the 125I-labelled EGF from the plasma of the ewe was found to be faster than the rate of disappearance of free [125I]iodide that had been injected into the ewe. 125I-Labelled EGF was also administered by a continuous infusion following an initial bolus injection. This again resulted in a rapid initial fall in radio-activity in blood, followed by a slow rise throughout the period of the infusion. When the infusion was stopped, there was a 15-min period of rapid readjustment, after which the radioactivity in the blood fell at a much slower rate (t½ ∼70 min) than was seen initially. Again, intact 125I-labelled EGF was transferred to urine throughout the experiment. At autopsy, 125I-labelled EGF was increased in bile, liver, thyroid and kidney. Although most of the 125I found in the thyroid was free iodide, some EGF-like material was also present. There was also EGF-like material found in both the kidney cortex and the kidney medulla. These results indicate that complex multi-compartment pathways for the uptake, distribution and clearance of 125I-labelled EGF exist in the sheep. Journal of Endocrinology (1989) 123, 121–130

INHIBITORY ACTION OF CALCIUM ON THE INACTIVATION OF ANTIDIURETIC HORMONE BY RAT KIDNEY SLICES

1963 ◽  
Vol 44 (4) ◽  
pp. 563-569 ◽  
Author(s):  
N. A. Thorn ◽  
N. B. S. Willumsen
Keyword(s):  
Arginine Vasopressin ◽  
Inhibitory Action ◽  
Calcium Concentration ◽  
Rat Kidney ◽  
Kidney Medulla ◽  
Marked Inhibition ◽  
High Calcium ◽  
Rational Explanation ◽  
High Calcium Concentration ◽  
Cellular Permeability

ABSTRACT Increasing the calcium concentration 5 times or more in the medium used for studying the inactivation of arginine-vasopressin by rat kidney medulla slices caused a marked inhibition of the inactivating activity of such slices. This effect was not found in homogenates of rat kidney medulla. The results are in agreement with the interpretation that the high calcium concentration decreased the cellular permeability to the hormone. This would seem to give a rational explanation of the vasopressin-resistant diabetes insipidus which is found in hypercalcaemia.

UT-B1 proteins in rat: tissue distribution and regulation by antidiuretic hormone in kidney

2002 ◽  
Vol 283 (5) ◽  
pp. F912-F922 ◽  
Author(s):  
M.-M. Trinh-Trang-Tan ◽  
F. Lasbennes ◽  
P . Gane ◽  
N. Roudier ◽  
P. Ripoche ◽  
...  
Keyword(s):  
Antidiuretic Hormone ◽  
Brain Cortex ◽  
Rat Kidney ◽  
Cross Reactivity ◽  
Ependymal Cells ◽  
Kidney Medulla ◽  
Vasa Recta ◽  
Cell Processes ◽  
Rat Tissue

UT-B1 is the facilitated urea transporter of red blood cells (RBCs) and endothelial cells of descending vasa recta in the kidney. Immunoblotting with a polyclonal antibody against the C-ter sequence of rat UT-B1 revealed UT-B1 as both nonglycosylated (29 kDa) and N-glycosylated (47.5 and 33 kDa) proteins in RBC membranes, kidney medulla, brain, and bladder in rat. In testis, UT-B1 was expressed only as a nonglycosylated protein of 47.5 kDa. Immunocytochemistry confirmed that the location of UT-B1 is restricted to descending vasa recta. In brain, UT-B1 protein was found in astrocytes and ependymal cells. Cell bodies and perivascular end feet of astrocytes were labeled in brain cortex, whereas astrocyte cell processes were labeled in corpus callosum. Flow cytometry analysis of RBCs revealed a good cross-reactivity of the antibody with mouse and human UT-B1. UT-B1 protein expression in rat kidney medulla was downregulated greatly by long-term [deamino-Cys1,d-Arg8]vasopressin infusion and moderately by furosemide treatment. This study discloses an uneven distribution of UT-B1 protein within astrocytes and the regulation of renal UT-B1 protein by antidiuretic hormone.

Comparison of the effects of Fe2+ and Cu2+ on prostaglandin synthesis in rabbit kidney medulla slices

1987 ◽  
Vol 39 (3) ◽  
pp. 230-233 ◽  
Author(s):  
Tadashi Fujita ◽  
Noboru Ohtani ◽  
Midori Aihara ◽  
Kazuyuki Nishioka ◽  
Yohko Fujimoto
Keyword(s):  
Prostaglandin Synthesis ◽  
Rabbit Kidney ◽  
Kidney Medulla

scholarly journals Comparison of the kinetic properties of the pyruvate dehydrogenase complex from pig kidney cortex and medulla.

1993 ◽  
Vol 40 (3) ◽  
pp. 411-419 ◽  
Author(s):  
T Pawełczyk ◽  
M S Olson
Keyword(s):  
Ionic Strength ◽  
Pyruvate Dehydrogenase ◽  
Pyruvate Dehydrogenase Complex ◽  
Product Inhibition ◽  
Hill Coefficient ◽  
Kidney Cortex ◽  
Kinetic Properties ◽  
Kidney Medulla ◽  
Pig Kidney ◽  
Dehydrogenase Complex

The activity of the pyruvate dehydrogenase complex (PDC) purified from pig kidney medulla was affected by K+, Na+, Cl-, HCO3-, HPO4(2-) and changes in ionic strength. Increased ionic strength influenced the activity of PDC from medulla by decreasing the Vmax and S0.5 for pyruvate and increasing the Hill coefficient. The magnitude of these changes was smaller than the corresponding changes for PDC purified from the cortex. In the presence of K+ (80 mM), Na+ (20 mM), Cl- (20 mM), HCO3- (20 mM), HPO4(2-) (10 mM) and at ionic strength of 0.15 M the S0.5 for pyruvate of PDC from medulla was 117 microM and the enzyme complex was saturated by 1.1 mM pyruvate. Under these conditions the S0.5 for pyruvate of PDC derived from cortex was 159 microM and the enzyme was saturated at 4.5 mM pyruvate. Based on the results presented in this report it is suggested that PDC in kidney medulla may be regulated not only by a phosphorylation/dephosphorylation system and end-product inhibition but also via changes in ionic strength.

Expression, functional analysis, and in situ hybridization of a cloned rat kidney collecting duct water channel

1994 ◽  
Vol 266 (1) ◽  
pp. C189-C197 ◽  
Author(s):  
T. Ma ◽  
H. Hasegawa ◽  
W. R. Skach ◽  
A. Frigeri ◽  
A. S. Verkman
Keyword(s):  
Base Pair ◽  
Collecting Duct ◽  
Rat Kidney ◽  
Water Channel ◽  
Cloning And Expression ◽  
Base Pairs ◽  
Kidney Medulla ◽  
Coding Sequence ◽  
Kidney Collecting Duct ◽  
Protein Size

The cloning and expression of an apical membrane water channel from rat kidney collecting duct (WCH-CD) homologous to a 28-kDa integral membrane protein (CHIP28) was reported recently (K. Fushimi, S. Uchida, Y. Hara, Y. Hirata, F. Marumo, and S. Sasaki. Nature Lond. 361: 549-552, 1993). We obtained an approximately 1.8-kilobase clone from a rat kidney lambda gt10 cDNA library by a polymerase chain reaction cloning method; whereas the coding sequence (814 base pairs, predicted protein size 29 kDa) was identical to that reported, we identified an in-frame ATG codon at base pair -123 predicting a protein size of 33 kDa. On Northern blots probed by cDNAs corresponding to the WCH-CD coding sequence (base pairs +1 to +814) or 5'-untranslated sequence (-403 to -16), a single band at 1.9 kilobases was observed in kidney medulla greater than in cortex but not in other tissues; mRNA expression was increased strongly by dehydration. Translation and oocyte expression studies were performed to identify the translation start site. The short (base pairs +1 to +814) and long (base pairs -123 to +814) cDNAs were subcloned in vector pSP64 containing the 5'-untranslated Xenopus globin sequence upstream to the ATGs; a 30-base pair c-myc sequence was engineered at the COOH- terminal for antibody recognition.(ABSTRACT TRUNCATED AT 250 WORDS)

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