scholarly journals Isolation and characterization of rabbit kidney brush borders

1972 ◽  
Vol 128 (5) ◽  
pp. 1319-1328 ◽  
Author(s):  
S. J. Quirk ◽  
G. B. Robinson
Keyword(s):  
Plasma Membranes ◽  
Sucrose Density Gradient ◽  
Molar Ratio ◽  
Rabbit Kidney ◽  
Kidney Cortex ◽  
Marker Enzymes ◽  
Isolation And Characterization ◽  
Adenosine Triphosphatases ◽  
Brush Borders

1. Brush borders were isolated from rabbit kidney-cortex homogenates by rate-zonal centrifugation through a sucrose density gradient in a B-XIV zonal rotor, followed by differential centrifugation. 2. The method of preparation gave brush borders of high purity with a reasonable yield. The morphological appearance supported the evidence from enzymic and chemical investigations, that the brush borders were only slightly contaminated with endoplasmic reticulum, mitochondria, lysosomes and nuclei. 3. The molar ratio of cholesterol to phospholipid lay within the range found in other plasma membranes, but the carbohydrate content was double that found in liver plasma membranes. 4. Alkaline phosphatase, maltase, trehalase and aminopeptidase were major enzymic constituents of the brush borders, and had an approximately equal yield and enrichment, but none of these enzymes fulfilled the criteria for marker enzymes. 5. Mg2+-dependent and Na+,K+-dependent adenosine triphosphatases, although found in brush borders, had low yields and low enrichments.

scholarly journals ISOLATION AND BIOCHEMICAL CHARACTERIZATION OF BRUSH BORDERS FROM RABBIT KIDNEY

1970 ◽  
Vol 47 (3) ◽  
pp. 637-645 ◽  
Author(s):  
Sosamma J. Berger ◽  
Bertram Sacktor
Keyword(s):  
Brush Border ◽  
Renal Cortex ◽  
Biochemical Characterization ◽  
Rabbit Kidney ◽  
Renal Tubules ◽  
Marker Enzymes ◽  
Alkaline Phosphatases ◽  
Brush Borders ◽  
Specific Activities

A technique for the isolation of intact brush borders from rabbit renal cortex was evaluated. The procedure was monitored by phase and electron microscopy and marker enzymes, i.e. ATP:NMN adenylyl transferase, nuclear; cytochrome oxidase, mitochondrial; ß-glucuronidase, lysosomal; and glucose-6-Pase, microsomal; and indicated an essentially pure preparation of brush borders. The disaccharidase, trehalase, previously reported in renal tubules, was localized uniquely in brush borders. Maltase was also found; the specific activities of the two enzymes in the brush borders were increased 10- to 20-fold. Other disaccharidases, such as sucrase, isomaltase, lactase, and cellobiase, were absent. It is suggested that trehalase and maltase are appropriate candidates for marker enzymes of the renal brush border. Isolated brush borders possessed a ouabain-sensitive (Na+ + K+) ATPase, an oligomycin-insensitive Mg++ ATPase, and a Ca++-activated ATPase. Alkaline phosphatases, dephosphorylating ß-glycero-P, and trehalose-6-P were also present. The specific activities of these enzymes were increased three-to-five fold in the brush-border preparations; however, activities were found in other subcellular fractions of the renal cortex. Hexokinase, although evident in the isolated brush border, was found prominently associated with other membranous fractions. Phosphoglucomutase and UDPG pyrophosphorylase were localized in the soluble fraction of the renal cortex.

Isolation and Characterization of a Microvascular Fraction from Rabbit Kidney Cortex

1984 ◽  
Vol 7 (3) ◽  
pp. 146-155 ◽  
Author(s):  
J.J. Helwig ◽  
C. Judes ◽  
C. Bollack ◽  
P. Mandel
Keyword(s):  
Rabbit Kidney ◽  
Kidney Cortex ◽  
Isolation And Characterization

Isolation and characterization of rabbit kidney brush borders

1972 ◽  
Vol 129 (5) ◽  
pp. 995.b1-995.b1
Author(s):  
S. J. Quirk ◽  
G B Robinson
Keyword(s):  
Rabbit Kidney ◽  
Isolation And Characterization ◽  
Brush Borders

scholarly journals Expression of Na+-independent amino acid transport in Xenopus laevis oocytes by injection of rabbit kidney cortex mRNA

1992 ◽  
Vol 281 (3) ◽  
pp. 717-723 ◽  
Author(s):  
J Bertran ◽  
A Werner ◽  
G Stange ◽  
D Markovich ◽  
J Biber ◽  
...  
Keyword(s):  
Amino Acids ◽  
Xenopus Laevis ◽  
Transport System ◽  
Sucrose Density Gradient ◽  
Rabbit Kidney ◽  
Kidney Cortex ◽  
Xenopus Laevis Oocytes ◽  
Transport Pathways ◽  
Arginine Uptake ◽  
Dose Dependent Increase

Poly(A)+ mRNA was isolated from rabbit kidney cortex and injected into Xenopus laevis oocytes. Injection of mRNA resulted in a time- and dose-dependent increase in Na(+)-independent uptake of L-[3H]alanine and L-[3H]arginine. L-Alanine uptake was stimulated about 3-fold and L-arginine uptake was stimulated about 8-fold after injection of mRNA (25-50 ng, after 3-6 days) as compared with water-injected oocytes. T.I.C. of oocyte extracts suggested that the increased uptake actually represented an increase in the oocyte content of labelled L-alanine and L-arginine. The expressed L-alanine uptake, obtained by subtracting the uptake in water-injected oocytes from that in mRNA-injected oocytes, showed saturability and was inhibited completely by 2-aminobicyclo[2,2,1]heptane-2-carboxylic acid (BCH) and L-arginine. The expressed L-arginine uptake in mRNA-injected oocytes also showed saturability, being completely inhibited by L-dibasic amino acids) and partially inhibited by BCH. Expression of both L-alanine and L-arginine uptake showed clear cis-inhibition by cationic (e.g. L-arginine) and neutral (e.g. L-leucine) amino acids. In all, this points to the expression of a Na(+)-independent transport system with broad specificity (i.e. b degree, (+)-like). In addition, part of the expressed uptake of L-arginine could be due to a system y(+)-like transporter. After size fractionation through a sucrose density gradient, the mRNA species encoding these increased transport activities (Na(+)-independent transport of L-alanine and of L-arginine) were found in fractions of an average mRNA chain-length of 1.8-2.4 kb. On the basis of these results, we conclude that Na(+)-independent transport system(s) for L-alanine and L-arginine from rabbit renal cortical tissues, most likely proximal tubules, are expressed in Xenopus laevis oocytes. These observations may represent the first steps towards expression and cloning of these transport pathways.

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