Quantitative Immunological Determination of Brush-Border Protein in Urine

2015 ◽  
pp. 119-125 ◽  
Author(s):  
A. W. Mondorf ◽  
J. E. Scherberich ◽  
W. Reitinger
Keyword(s):  
Brush Border

Determination of the Catalytic Groups of Intestinal Brush-Border Sucrase by pH-Variation Studies

1979 ◽  
Vol 7 (5) ◽  
pp. 1071-1072 ◽  
Author(s):  
CHARLES TELLIER ◽  
NICOLE BERTRAND-TRIADOU ◽  
FRANCISCO ALVARADO
Keyword(s):  
Brush Border ◽  
Ph Variation ◽  
Intestinal Brush Border

scholarly journals Determination of unidirectional uptake rates for lipids across the intestinal brush border

1972 ◽  
Vol 13 (2) ◽  
pp. 184-192
Author(s):  
Verney L. Sallee ◽  
Frederick A. Wilson ◽  
John M. Dietschy
Keyword(s):  
Brush Border ◽  
Intestinal Brush Border ◽  
Uptake Rates

scholarly journals Immunoferritin determination of the distribution of (Na+ + K+) ATPase over the plasma membranes of renal convoluted tubules. II. Proximal segment.

1976 ◽  
Vol 68 (2) ◽  
pp. 304-318 ◽  
Author(s):  
J Kyte
Keyword(s):  
Brush Border ◽  
Plasma Membranes ◽  
Fluid Transport ◽  
Gamma Globulin ◽  
Rabbit Kidney ◽  
Isotonic Fluid ◽  
High Concentrations ◽  
Ultrathin Frozen Sections ◽  
Convoluted Tubules

The distribution of (Na+ + K+) ATPase over the plasma membranes of the proximal convoluted tubule from canine renal cortex has been determined. Ultrathin frozen sections of this tissue were stained with rabbit antibodies to this enzyme and ferritin-conjugated goat antirabbit gamma-globulin. It is demonstrated that high concentrations of this enzyme uniformly line the intercellular spaces of this epithelium. The consequences of this observation are discussed in terms of the low resistant tight junctions of these tubules and the isotonic fluid transport which they support. Furthermore, antibodies to (Na+ + K+) ATPase recognize an antigen on the luminal surfaces of the tubules within the brush border. It is proposed that the enzyme is present in this region of the plasma membrane as well, although at much lower concentration. To further substantiate this conclusion, a brush border fraction has been purified from rabbit kidney and been shown to contain significant (Na+ + K+) ATPase. These results contradict earlier conclusions about the location of (Na+ + K+) ATPase in this tissue.

Acid/base transport in a model of the proximal tubule brush border: impact of carbonic anhydrase

1996 ◽  
Vol 270 (2) ◽  
pp. F344-F355 ◽  
Author(s):  
T. A. Krahn ◽  
A. M. Weinstein
Keyword(s):  
Carbonic Anhydrase ◽  
Formic Acid ◽  
Proximal Tubule ◽  
Brush Border ◽  
Unstirred Layer ◽  
Facilitated Diffusion ◽  
Ph Gradients ◽  
Math Biol ◽  
The Impact

A mathematical model of the brush border of the proximal tubule (T. A. Krahn, P. S. Aronson, and A. M. Weinstein. Bull. Math. Biol, 56: 459-490, 1994) has been extended by the inclusion of CO2 and H2CO3 as diffusible species and by the inclusion of finite rate constants for the hydration of CO2. This permits the simulation of carbonic anhydrase (CA) activity and its inhibition. We confirm the result of our previous study, which is that, in the presence of CA, the unstirred layer has only a modest effect on the observed formic acid permeability. CA inhibition results in disequilibrium pH gradients, and the effect of these gradients on formic acid permeability depends on the presence of other membrane transport proteins. We also examined the impact of CA activity on the flux of total CO2 through the brush border. Under physiological conditions, CA inhibition depressed NaHCO3 reabsorption through the brush border by interfering with the HCO3(-)-facilitated diffusion of CO2. However, the determination of brush-border CO2 permeability, using an imposed CO2 gradient, was relatively uninfluenced by CA activity. Finally, we inserted a kinetic representation of the Na+/H+ exchanger into the brush-border model. Even when luminal and cytosolic diffusion coefficients were increased 1,000-fold, there was no effect on brush-border Na+ flux. This suggests that variations in the unstirred layer cannot be responsible for the flow dependence of Na+ reabsorption.

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