Membrane fluidity and enzyme activities in brush border and basolateral membranes of the dog kidney

1982 ◽  
Vol 242 (3) ◽  
pp. F246-F253 ◽  
Author(s):  
C. Le Grimellec ◽  
M. C. Giocondi ◽  
B. Carriere ◽  
S. Carriere ◽  
J. Cardinal
Keyword(s):  
Alkaline Phosphatase ◽  
Brush Border ◽  
Plasma Membranes ◽  
Physical State ◽  
Arrhenius Plot ◽  
Membrane Lipids ◽  
Basolateral Membranes ◽  
Brush Border Membranes ◽  
Dog Kidney ◽  
Additional Support

The physical state of membrane lipids and relationships with the activity of Na+-K+-ATPase and alkaline phosphatase were studied in basolateral and brush border membranes of the dog kidney. Fluorescence polarization and electron spin resonance experiments demonstrate that basolateral membranes are much more fluid than brush border membranes. This can be accounted for by a difference in fluidity of the lipid part of the membranes. Broad (43-17 degrees C) thermotropic transitions are observed in liposomes made from total lipid extracts of brush border and basolateral membranes. Fluorescence data strongly suggest that thermotropic transitions also occur in intact membranes and that a change in membrane physical state may take place around the physiological temperature. A nonlinear Arrhenius plot for the Na+-K+-ATPase activity in basolateral membranes (breakpoint 21 degrees C) provides additional support for the existence of a lipid liquid leads to gel transition in antiluminal plasma membranes. A break in the Arrhenius plot of alkaline phosphatase activity is also observed but at a temperature significantly higher (26 degrees C) than that of the end of the thermotropic transition. "Room temperature" appears as a critical zone for lipid physical state and activities of both enzymes.

Effect of meleate on membrane physical state of brush border and basolateral membranes of the dog kidney

Life Sciences ◽  
1982 ◽  
Vol 30 (13) ◽  
pp. 1107-1111 ◽  
Author(s):  
Christian Le Grimellec ◽  
Serge Carrière ◽  
Jean Cardinal ◽  
Marie-Cécile Giocondi
Keyword(s):  
Brush Border ◽  
Physical State ◽  
Basolateral Membranes ◽  
Dog Kidney

scholarly journals Polarized subcellular distribution of the 1-, 4- and 5-phosphatase activities that metabolize inositol 1,4,5-trisphosphate in intestinal epithelial cells

1990 ◽  
Vol 269 (2) ◽  
pp. 353-358 ◽  
Author(s):  
C Rubiera ◽  
P S Lazo ◽  
S B Shears
Keyword(s):  
Epithelial Cells ◽  
Brush Border ◽  
Subcellular Distribution ◽  
Plasma Membranes ◽  
Inositol Phosphates ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Phosphatase Activities ◽  
Basolateral Membranes ◽  
Brush Border Membranes

In intestinal epithelial cells, Ins(1,4,5)P3 is metabolized both by an intracellular 5-phosphatase and by less specific extracellular phosphatases [Rubiera, Velasco, Michell, Lazo & Shears (1988) Biochem. J. 255, 131-137]. A total of 91% of intracellular Ins(1,4,5)P3 5-phosphatase was particulate, and was preferentially associated with plasma membranes rather than with other subcellular organelles. A soluble Ins(1,4,5)P3 3-kinase activity was also characterized, further supporting the idea that inositol phosphates are important in enterocyte function. We have studied the distribution of Ins(1,4,5)P3 phosphatase activities in basolateral and brush-border domains of the plasma membrane. Compared with homogenates, the extracellular phosphatases were 13-17-fold enriched in brush-border membranes, but only 2-fold enriched in basolateral membranes. The 1- and 4-phosphates of Ins(1,4,5)P3 were hydrolysed at equal rates by the extracellular phosphatases; these enzymes are proposed to have digestive functions. The intracellular particulate 5-phosphatase was 2-fold enriched in brush-border membranes and 13-fold enriched in basolateral membranes, at the same pole of the cell where Ins(1,4,5)P3 is believed to be generated. This is opposite to the polarized distribution of particulate 5-phosphatase in hepatocytes [Shears, Evans, Kirk & Michell (1988) Biochem. J. 256, 363-369]; these differences in subcellular distribution may be important in determining cell-specific metabolism of Ins(1,4,5)P3.

scholarly journals The effect of diets adequate and deficient in calcium on blood pressures and the activities of intestinal and kidney plasma membrane enzymes in normotensive and spontaneously hypertensive rats

1990 ◽  
Vol 63 (1) ◽  
pp. 65-78 ◽  
Author(s):  
Peter Blakeborough ◽  
Sheila G. Neville ◽  
Brian A. Rolls
Keyword(s):  
Alkaline Phosphatase ◽  
Brush Border ◽  
Shr Rats ◽  
Deficient Diet ◽  
Spontaneously Hypertensive ◽  
Adequate Diet ◽  
Basolateral Membranes ◽  
Brush Border Membranes ◽  
Wky Rats ◽  
Blood Pressures

Basolateral and brush-border membranes were prepared from the intestines and kidneys of spontaneously hypertensive (SHR) and normotensive (WKY) rats fed on a calcium-adequate diet and assayed for their enzyme activities. In intestinal basolateral membranes the activities of Na+ K+-ATPase (EC 3.6.1.37) Ca2+-ATPase (EC 3.6.1.38) and alkaline phosphatase (EC 3.1.3.1) were lower in SHR rats when compared with WKY rats, whilst 5'-nucleotidase (EC3.1.3.5) (a marker for basolateral membranes) was unaffected. In kidney basolateral membranes all enzymes were similar in activity in SHR and WKY rats. In intestinal brush-border membranes the activities of Ca2+-ATPase and alkaline phosphatase were lower in SHR rats when compared with WKY rats, whilst microvillus aminopeptidase (EC 3.4.11.2) (a marker for brush-border membranes) was unaffected. In kidney brush-border membranes all enzymes were similar in activity in SHR and WKY rats. The blood pressures of the SHR rats were considerably higher than those of the WKY rats. When SHR rats were fed on a Ca-deficient diet the activities of Na+K+-ATPase, Ca2+-ATPase and alkaline phosphatase in basolateral membranes and Ca2+-ATPase and alkaline phosphatase in brush-border membranes were all increased in the intestine when compared with SHR rats fed on a Ca-adequate diet. The equivalent enzymes in the kidneys of SHR rats, and the intestines and kidneys of WKY rats, were not affected by altering the Ca in the diet. The blood pressures of SHR rats fed on a Ca-deficient diet were higher than in those fed on a Ca-adequate diet. Blood pressures of WKY rats were not affected by altering the diet in this way. The results indicate that the absorption of Ca by active mechanisms may be reduced in SHR rats compared with WKY rats. Changing the level of Ca in the diet modified both blood pressure and the activities of enzymes which catalyse active Ca transport. The implications of these results to the aetiology, and possible nutritional treatment, of essential hypertension are discussed.

scholarly journals Alkaline phosphatase from pig kidney. Method of purification and molecular properties

1974 ◽  
Vol 141 (1) ◽  
pp. 273-282 ◽  
Author(s):  
Ernst D. Wachsmuth ◽  
Kunio Hiwada
Keyword(s):  
Alkaline Phosphatase ◽  
Brush Border ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Molecular Properties ◽  
Purification Procedure ◽  
Brush Border Membranes ◽  
Pig Kidney ◽  
Critical Ph

Alkaline phosphatase (EC 3.1.3.1) from pig kidney brush-border membranes was solubilized from membrane precipitates by butan-1-ol at a critical pH of 7.0. The 12000-fold purification procedure included (NH4)2SO4 precipitation, DEAE-and TEAE-cellulose chromatography, Sephadex G-200 gel filtration and neuraminidase digestion followed by DEAE-cellulose chromatography. The purified protein contained 20% (w/w) carbohydrate and had mol.wt. 150000–156000 as estimated by Sephadex filtration and ultracentrifuge analysis. It was a tetrameric glycoprotein consisting of identical subunits, and it had a molecular activity at 25°C of 2600s-1 per tetramer. Its concentration in kidney was estimated to be 8.5–8.8mg/kg.

Sodium-adenosine cotransport in brush-border membranes from rabbit ileum

1990 ◽  
Vol 259 (3) ◽  
pp. G504-G510 ◽  
Author(s):  
S. L. Betcher ◽  
J. N. Forrest ◽  
R. G. Knickelbein ◽  
J. W. Dobbins
Keyword(s):  
Brush Border ◽  
Membrane Vesicles ◽  
Transport Systems ◽  
Rabbit Ileum ◽  
Basolateral Membranes ◽  
Brush Border Membranes ◽  
Intestinal Epithelia ◽  
Adenosine Uptake ◽  
Adenosine Concentration ◽  
Adenosine Transport

To determine the mechanism(s) of transcellular adenosine transport in epithelial tissues that possess an adenosine receptor response, we studied [3H]adenosine uptake using vesicles prepared from isolated brush-border and basolateral membranes of the rabbit ileum. In the presence of the adenosine deaminase inhibitor deoxycoformycin uptake of [3H]adenosine into brush-border membrane vesicles is stimulated fivefold by an inwardly directed Na gradient. Na-dependent [3H]adenosine uptake is enhanced and concentrative under conditions that increase inside negativity of vesicles, thus providing evidence for an electrogenic carrier. Na-dependent adenosine uptake is a saturable function of adenosine concentration with a Michaelis-Menten constant of 17.3 +/- 7.1 microM and maximum transport rate of 216.9 +/- 20.2 pmol.min-1.mg protein-1. Both uridine and inosine inhibit [3H]adenosine uptake, suggesting that the Na-dependent transporter has broad substrate specificity for both purine and pyrimidine ribonucleosides. Na-dependent adenosine uptake is inhibited by dipyridamole but is insensitive to 6-(4-nitrobenzyl)thio-9-beta-D-ribofuranosylpurine. We conclude that adenosine is transported across ileal brush-border membranes by a Na-ribonucleoside cotransport system. In contrast, adenosine uptake in basolateral membranes is not stimulated by a Na gradient. These studies show asymmetry in the distribution of transport systems for adenosine in polarized intestinal epithelia.

Angiotensin II receptor subtypes in eel (Anguilla anguilla)

1994 ◽  
Vol 12 (1) ◽  
pp. 61-69 ◽  
Author(s):  
S Marsigliante ◽  
T Verri ◽  
S Barker ◽  
E Jimenez ◽  
G P Vinson ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Brush Border ◽  
Binding Sites ◽  
Plasma Membranes ◽  
Anguilla Anguilla ◽  
Receptor Subtypes ◽  
European Eel ◽  
Ang Ii ◽  
Brush Border Membranes ◽  
Renal Brush Border Membrane

ABSTRACT Previous studies have shown the effects of angiotensin II (Ang II) in teleosts, and Ang II-binding sites have also been localized in tissues from rainbow trout. The purpose of this study was to extend these findings and to provide an analysis of Ang II receptor (Ang II-R) isoforms in three tissues obtained from European eel (Anguilla anguilla). Ang II-Rs were identified in eel liver, kidney and intestine membranes by the binding of either 0·5 nmol human 125I-labelled Tyr4-lle5-Ang II/l or increasing concentrations (1–120 nmol/l) of [3,5-3H]Tyr4-Ile5-Ang II. Using an isoelectric focusing technique, two Ang II-binding sites were identified in liver membranes. These migrated to isoelectric points (pI values) 6·5 and 6·7. Seventy per cent of binding to both sites was displaced by a 10 000-fold excess of unlabelled human Ang II. In both whole plasma membranes and brush border membranes from intestine, only one form of the Ang II-R was found, with pI 6·5 and high affinity (Kd=3·4 nmol/l) for the [3,5-3H]Tyr4-Ile5-Ang II. Similarly, only the isoform focusing at pI 6·5 was observed in renal tubular epithelial brush border membranes. Reduction of disulphide bridges with dithiothreitol significantly enhanced Ang II binding to the isoform at pI 6·5 in liver (P<0·05) and kidney (P<0·01), while in liver the binding to the isoform of pI 6·7 was significantly reduced (P<0·001). The data suggest the existence in eel liver of multiple forms of Ang II-R, which may have different functions, while one single form appeared to be present in enterocyte plasma membrane and in renal brush border membrane.

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