Transport defects of rabbit inner medullary collecting duct cells in obstructive nephropathy
| Autor: | M. R. Sullivan, Subbarao V. Yalla, Michael Kashgarian, T. R. Kleyman, G. Otuechere, Mark L. Zeidel, Shang-Jyh Hwang, D. J. Benos, Hobart W. Harris |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
medicine.medical_specialty
Physiology Sodium ATPase Immunoblotting chemistry.chemical_element Sodium Channels Reference Values Internal medicine Renal medulla Animals Medicine Kidney Tubules Collecting Na+/K+-ATPase Kidney Medulla Kidney Lagomorpha biology Reabsorption business.industry Cell Membrane Biological Transport Membrane transport biology.organism_classification medicine.anatomical_structure Endocrinology chemistry biology.protein Rabbits Sodium-Potassium-Exchanging ATPase business Ureteral Obstruction |
| Zdroj: | American Journal of Physiology-Renal Physiology. 264:F808-F815 |
| ISSN: | 1522-1466 1931-857X |
| DOI: | 10.1152/ajprenal.1993.264.5.f808 |
| Popis: | Urinary obstruction markedly reduces collecting duct Na+ reabsorption. To define the cellular mechanisms of this derangement in Na+ reabsorption in inner medullary collecting duct (IMCD) of obstructed kidneys, suspensions of intact IMCD cells and inner medulla plasma membranes (IMPM) were prepared from 24 h obstructed and untreated control kidneys. Oxygen consumption (QO2) studies revealed marked reductions in both amiloride-sensitive and ouabain-sensitive QO2 but not ouabain-insensitive QO2 in intact IMCD cells from obstructed, compared with control animals, indicating a reduction in oxygen-dependent transport activities of both the Na+ channel and the Na(+)-K(+)-adenosinetriphosphatase (ATPase). Amiloride-sensitive conductive 22Na+ uptake in intact IMCD cells from obstructed kidneys was significantly decreased by 45% at 10 s, 30 s, and 1-5 min (10 s: 2.42 +/- 0.63 vs. 4.49 +/- 0.64 nmol Na+ flux/mg protein, n = 7, P < 0.05; 1 min: 4.65 +/- 0.7 vs. 8.27 +/- 0.98 nmol Na+ flux/mg protein, n = 7, P < 0.05), indicating decreased activity of amiloride-sensitive Na+ channels in these cells. However, immunoblots of IMPM with antibodies to Na+ channel proteins did not show significant differences in content of Na+ channel proteins between membranes from obstructed and control groups. Ouabain-sensitive Na(+)-K(+)-ATPase activity in IMPM of obstructed kidneys was also reduced (61.1 +/- 18.1 vs. 152.6 +/- 25.8 nmol ATP degradation.min-1.mg protein-1, n = 6, P < 0.02), and immunoblots with monoclonal antibodies against the alpha 1- and beta-subunits of rabbit Na(+)-K(+)-ATPase showed a 51 +/- 7% reduction of both subunits in IMPM from obstructed kidneys (n = 4).(ABSTRACT TRUNCATED AT 250 WORDS) |
| Databáze: | OpenAIRE |
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