Studies on the mechanism of action of calciferol III. Vitamin D-mediated increase of intestinal brush border alkaline phosphatase activity

1970 ◽  
Vol 215 (2) ◽  
pp. 348-359 ◽  
Author(s):  
A.W. Norman ◽  
A.K. Mircheff ◽  
T.H. Adams ◽  
A. Spielvogel
Keyword(s):  
Vitamin D ◽  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Mechanism Of Action ◽  
Alkaline Phosphatase Activity ◽  
Brush Border ◽  
Intestinal Brush Border

scholarly journals Effects of dietary fish oil supplementation on membrane fluidity and enzyme activity in rat small intestine

1989 ◽  
Vol 263 (1) ◽  
pp. 41-45 ◽  
Author(s):  
W F Stenson ◽  
B Seetharam ◽  
V Talkad ◽  
W Pickett ◽  
P Dudeja ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Fatty Acid ◽  
Fish Oil ◽  
Membrane Fluidity ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Brush Border ◽  
Phospholipid Fatty Acid ◽  
Intestinal Brush Border ◽  
Fish Oil Supplementation

Rats were fed either a fat-free diet supplemented with 10% menhaden oil or a control diet for four months. Intestinal brush border membranes were isolated; phospholipid fatty acid analysis revealed that the membranes from the fish-oil fed animals had higher levels of palmitoleic (C16:1) and eicosapentaenoic (C20:5) acids and lesser levels of stearic (C18:0) linoleic (C18:2) acids compared with controls. The membranes from the fish-oil fed animals had increased levels of alkaline phosphatase activity compared with controls but disaccharidase levels were equivalent in the two groups. Rocket immunoelectrophoresis studies revealed that the increase in alkaline phosphatase activity was due to an increase in the specific activity of the enzyme rather than an increase in the amount of enzyme. Membrane fluidity was assessed by fluorescence anisotropy using diphenylhexatriene and 12-anthroyl stearate as fluorescent probes. The anisotropy of both probes was similar in the two membranes. These studies indicate that fish-oil supplementation alters the fatty acid composition of the intestinal brush border membrane and increases alkaline phosphatase activity without affecting membrane fluidity. Thus the effects of changes in membrane lipid composition on alkaline phosphatase activity appear to result from changes in the local lipid environment of the enzyme rather than from changes in the biophysical characteristics of the membrane.

scholarly journals Identification of intestinal cells responsive to calcitriol (1,25-dihydroxycholecalciferol)

1985 ◽  
Vol 225 (1) ◽  
pp. 127-133 ◽  
Author(s):  
M W Smith ◽  
M E Bruns ◽  
E D M Lawson
Keyword(s):  
Vitamin D ◽  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Quantitative Description ◽  
Intestinal Cells ◽  
Protein Levels ◽  
High Affinity ◽  
Hormone Injection ◽  
Crypt Cells

The location of intestinal cells taken from the base of the crypt to the tip of the villus responsive to calcitriol (1,25-dihydroxycholecalciferol) and the distribution of [3H]calcitriol within the intestinal epithelium has been determined in vitamin D-deficient rats. The calcitriol responses examined were CaBP (Ca2+-binding protein) levels as measured by immunodiffusion and alkaline phosphatase levels as determined cytochemically. Calcitriol had no effect on villus structure or on enterocyte kinetics. This made it possible to compare levels of CaBP and alkaline phosphatase activity in enterocytes at different ages in rats at known times after hormone injection. Cells from both the crypt and villus synthesized CaBP in response to calcitriol. Alkaline phosphatase activity was not detectable in crypt cells, although a pool of precursor was produced in these cells in response to calcitriol. Enzyme activity was increased in all villus cells in response to calcitriol, but the quantitative description of this effect was very different from that found for calcitriol effects on CaBP synthesis. Calcitriol injected into vitamin D-deficient rats was detected, within 2h, in all cells of the crypt and villus. Most of the binding was to sites having a high affinity for the injected hormone.

Induction of Intestinal Brush Border Alkaline Phosphatase by Vitamin D and Identity with Ca-ATPase

Nature ◽  
1970 ◽  
Vol 228 (5277) ◽  
pp. 1199-1201 ◽  
Author(s):  
MARK R. HAUSSLER ◽  
LARRY A. NAGODE ◽  
HOWARD RASMUSSEN
Keyword(s):  
Vitamin D ◽  
Alkaline Phosphatase ◽  
Brush Border ◽  
Intestinal Brush Border

Enhancement of vitamin D3 effect on bone metabolism in weanling rats orally administered zinc sulphate

1986 ◽  
Vol 111 (2) ◽  
pp. 285-288 ◽  
Author(s):  
Masayoshi Yamaguchi ◽  
Teruyuki Sakashita
Keyword(s):  
Vitamin D ◽  
Alkaline Phosphatase ◽  
Bone Metabolism ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Dna Content ◽  
Zinc Sulphate ◽  
Simultaneous Administration ◽  
Weanling Rats ◽  
Stimulation Of

Abstract. The interaction of vitamin D3 and zinc on bone metabolism was investigated in the femur of weanling rats. Oral administration of vitamin D3 (1.0 μg/100 g body weight) did not cause any increase in the zinc accumulation in the femoral tissue following treatment with zinc sulphate (1.0 mg Zn/100 g). Administration of vitamin D3 or zinc produced significant increases the alkaline phosphatase activity and DNA content of the femoral diaphvsis but not of the epiphysis. The increase in alkaline phosphatase activity was enhanced additionally by simultaneous administration of vitamin D3 and zinc. Moreover, the increase in DNA content was enhanced markedly (about 4 times) by these treatments. At a dose of 0.5 μg of vitamin D3 per 100 g, DNA content was at the control level. This level was increased about 2 times by simultaneous administration of zinc (1.0 mg/100 g). The increase in alkaline phosphatase activity following simultaneous administration of vitamin D3 and zinc was significantly inhibited by treatment with cycloheximide, actinomycin D, or mitomycin C. Also, the increase in DNA content was completely inhibited by mitomycin C treatment. The present data suggest that the combination of vitamin D3 and zinc has a multiple effect on the stimulation of bone growth and mineralization in weanling rats, and that this effect is based on a stimulation of the DNA synthesis in bone cells.

Presence of γ-glutamyltransferase in the renal microvascular compartment

1981 ◽  
Vol 59 (6) ◽  
pp. 383-386 ◽  
Author(s):  
P. D. Dass ◽  
R. P. Misra ◽  
T. C. Welbourne
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Density Gradient ◽  
Alkaline Phosphatase Activity ◽  
Brush Border ◽  
Sucrose Density Gradient ◽  
Isolated Glomeruli ◽  
Crude Homogenate ◽  
Brush Border Enzyme ◽  
Enzyme Alkaline Phosphatase

The association between the brush border enzyme alkaline phosphatase and γ-glutamyltransferase was determined by sucrose density gradient analysis of crude kidney homogenates, isolated glomeruli, and isolated microvessels. As previously established there is an overlap of these enzyme activities in the crude homogenate corresponding to a density of 1.17 g∙cm−3. In contrast, isolated glomeruli sedimented with a peak of 1.25 g∙cm−3 and exhibited γ-glutamyltransferase activity but little alkaline phosphatase activity; homogenizing isolated glomeruli shifted the fragments to a density coincident with that observed for the crude homogenate γ-glutamyltransferase peak. A second population of capillaries, isolated microvessels, were homogenized and analyzed on the sucrose density gradient. These fragments sedimented over the same range as crude homogenate γ-glutamyltransferase peak but were devoid of alkaline phosphatase activity and yet exhibited remarkable γ-glutamyltransferase activity. The results indicate homogenization of renal cortex results in a heterogenous collection of particles from both tubular and microvascular locations exhibiting γ-glutamyltransferase activity which overlap with the brush border alkaline phosphatase containing membranes. However, isolation of microvessels and glomeruli prior to homogenization allows separation of γ-glutamyltransferase from alkaline phosphatase activity; between 10 and 20% of the total homogenate γ-glutamyltransferase activity is estimated to be associated with the microvascular compartment.

scholarly journals Alkaline phosphatase activity does not mediate phosphate transport in the renal-cortical brush-border membrane

1980 ◽  
Vol 190 (2) ◽  
pp. 473-476 ◽  
Author(s):  
H S Tenenhouse ◽  
C R Scriver ◽  
E J Vizel
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Brush Border ◽  
Brush Border Membrane ◽  
Membrane Vesicles ◽  
Phosphate Transport ◽  
Mouse Kidney ◽  
Brush Border Membrane Vesicles ◽  
Low Phosphorus

We studied (1) the effect of primary modulators of phosphate transport, namely the hypophosphataemic mouse mutant (Hyp) and low-phosphorus diet, on alkaline phosphatase activity in mouse renal-cortex brush-border membrane vesicles and (2) the effect of several primary inhibitors of alkaline phosphatase on phosphate transport. Brush-border membrane vesicles from Hyp-mouse kidney had 50% loss of Na+-dependent phosphate transport, but only 18% decrease in alkaline phosphatase activity. The low-phosphorus diet effectively stimulated Na+/phosphate co-transport in brush-border membrane vesicles (+ 118%), but increased alkaline phosphatase activity only slightly (+13%). Levamisole (0.1 mM) and EDTA (1.0 mM) inhibited brush-border membrane-vesicle alkaline phosphatase activity of 82% and 93% respectively, but had no significant effect on Na+/phosphate co-transport. We conclude that alkaline phosphatase does not play a direct role in phosphate transport across the brush-border membrane of mouse kidney.

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