Analysis of Na+-D-glucose cotransporter and other renal brush border proteins in human urine
| Autor: | G. Schütterle, Hermann Koepsell, Horst-Walter Birk, Jochem Kötting, Stefan Piberhofer, Winfried Haase |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Adult
Male medicine.medical_specialty Adolescent Brush border Swine Kidney digestive system Excretion Internal medicine medicine Animals Humans Antigens Lipid bilayer Microvilli biology Chemistry Vesicle Sodium Antibodies Monoclonal Membrane Proteins Molecular biology Rats Glucose Endocrinology medicine.anatomical_structure Membrane protein Nephrology biology.protein Female Carrier Proteins Villin Cotransporter |
| Zdroj: | Kidney International. 40:823-837 |
| ISSN: | 0085-2538 |
| DOI: | 10.1038/ki.1991.282 |
| Popis: | Analysis of Na + -D-glucose cotransporter and other renal brush border proteins in human urine. A sensitive quantitative radioimmunoassay is described by which different antigens in the urine can be assayed simultaneously. Urinary excretion of three proteins from proximal tubules was compared: 1) the Na + -D-glucose cotransporter from brush border membranes and subapical vesicles; 2) a kidney-specific hydrophobic M r 400,000 polypeptide from intermicroviUar invaginations and subapical vesicles; and 3) villin from microvilli cores. In the normal urine about 50% of the excreted Na + -D-glucose cotransporter and villin, and about 25% of the M r 400,000 polypeptide was associated with brush border membrane vesicles, whereas trie remaining fractions of the three proteins formed small sedimentable aggregates which contained some cholesterol and fatty acids but no phospholipids. The normal urinary excretion of the Na + -D-glucose cotransporter was correlated with that of villin and the M r 400,000 polypeptide. The data show that membrane proteins from the proximal tubule are excreted by the shedding of different brush border membrane areas. They suggest that some microvilli are released in total, and that a large fraction of the brush border membrane proteins is excreted without being associated with a phospholipid bilayer. In an attempt to define protein excretion patterns during kidney malfunctions, the excretion of brush border membrane proteins was analyzed after one intravenous injection of the X-ray contrast medium, iopamidol. No change in villin excretion was observed, but a reversible increase in the excretion of brush border membrane proteins was found in patients without diabetes. With diabetes a more pronounced iopamidol effect on the excretion of brush border membrane proteins and a significant increase in the excretion of villin was observed. |
| Databáze: | OpenAIRE |
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