scholarly journals Immunocytochemical localization of the vitamin D-dependent calcium binding protein in chick duodenum.

1982 ◽  
Vol 94 (1) ◽  
pp. 115-122 ◽  
Author(s):  
B Thorens ◽  
J Roth ◽  
A W Norman ◽  
A Perrelet ◽  
L Orci
Keyword(s):  
Vitamin D ◽  
Brush Border ◽  
Calcium Binding ◽  
High Speed ◽  
Binding Protein ◽  
Protein A ◽  
Calcium Binding Protein ◽  
Electron Microscopic Level ◽  
Supernatant Fraction ◽  
Electron Microscopic

The vitamin D-dependent calcium binding protein (CaBP) of chick duodenum has been localized by immunocytochemistry and by radioimmunoassay. Light microscopically, CaBP was seen to be present in the absorptive cells of the villi while in other cell types of the villi and the crypts, including goblet cells and endocrine cells, no CaBP was seen. At the electron microscopic level, CaBP was shown to be localized in the cytosol and the euchromatin of the nucleus but not in membrane-bounded cytoplasmic compartments. Quantitative evaluation of the immunocytochemical protein A-gold label showed that the terminal web and the cytosol of basal cellular regions were most highly labeled while the brush border was weakly labeled. The radioimmunoassay evaluation of intestinal subcellular fractions indicated that 96% of the homogenate CaBP is in the cytosol high-speed supernatant fraction. Collectively, these results support the hypothesis that the vitamin D-dependent intestinal CaBP may play a role in either regulation of intracellular calcium concentration or movement of calcium across the brush border membrane from the gut lumen.

Localization of the vitamin D-dependent calcium-binding protein in mammalian kidney

1982 ◽  
Vol 243 (3) ◽  
pp. F243-F252 ◽  
Author(s):  
J. Roth ◽  
D. Brown ◽  
A. W. Norman ◽  
L. Orci
Keyword(s):  
Vitamin D ◽  
Calcium Binding ◽  
Binding Protein ◽  
Collecting Duct ◽  
Rat Kidney ◽  
Protein A ◽  
Human Kidney ◽  
Calcium Binding Protein ◽  
Medullary Collecting Duct ◽  
Convoluted Tubules

The vitamin D-dependent calcium-binding protein (CaBP) was localized by immunocytochemistry in the rat and human kidney. In both species 80% of the cells lining the distal convoluted tubules contained CaBP. In the connecting segment and the initial collecting tubule of rat kidney, 50% of the cells was positive; in the outer medullary collecting duct only 15% was positive. In the human kidney, collecting ducts in medullary rays contained 50% positive cells, whereas in the rest of the medulla no positive cells were found. The CaBP-positive cells were identified as principal or clear cells by immunoelectron-microscopy, using the protein A-gold technique. Mitochondria-rich dark cells were negative. In principal cells, CaBP immunoreactive sites were found throughout the cytosol and the nuclear euchromatin. No preferential labeling of cellular membranes was found. The data show that CaBP-positive cells are present in tubular regions that are important in regulating the final excretion of calcium. However, the subcellular distribution of CaBP does not suggest a role in the initial transmembrane transport of Ca2+ but rather indicates an involvement in processes regulating intracellular calcium.

IMMUNOCYTOCHEMISTRY OF VITAMIN D-DEPENDENT CALCIUM BINDING PROTEIN IN CHICK PANCREAS: EXCLUSIVE LOCALIZATION IN B-CELLS.*

Endocrinology ◽  
1982 ◽  
Vol 110 (6) ◽  
pp. 2216-2218 ◽  
Author(s):  
JURGEN ROTH ◽  
SUSAN BONNER-WEIR ◽  
ANTHONY W. NORMAN ◽  
LELIO ORCI
Keyword(s):  
Vitamin D ◽  
B Cells ◽  
Calcium Binding ◽  
Binding Protein ◽  
Calcium Binding Protein

scholarly journals Vitamin D-dependent Calcium-binding Protein

1968 ◽  
Vol 243 (14) ◽  
pp. 3978-3986 ◽  
Author(s):  
R H Wasserman ◽  
R A Corradino ◽  
A N Taylor
Keyword(s):  
Vitamin D ◽  
Calcium Binding ◽  
Binding Protein ◽  
Calcium Binding Protein

scholarly journals Vitamin D-dependent Calcium-binding Protein

1968 ◽  
Vol 243 (14) ◽  
pp. 3987-3993 ◽  
Author(s):  
R H Wasserman ◽  
A N Taylor
Keyword(s):  
Vitamin D ◽  
Calcium Binding ◽  
Binding Protein ◽  
Calcium Binding Protein

scholarly journals In situ detection of vitamin D-induced calcium-binding protein (9-kDa CaBP) messenger RNA in rat duodenum.

1986 ◽  
Vol 34 (2) ◽  
pp. 277-280 ◽  
Author(s):  
M Warembourg ◽  
O Tranchant ◽  
C Perret ◽  
C Desplan ◽  
M Thomasset
Keyword(s):  
Vitamin D ◽  
In Situ Hybridization ◽  
Calcium Binding ◽  
Binding Protein ◽  
Cdna Probe ◽  
Calcium Binding Protein ◽  
Pbr322 Dna ◽  
Rat Duodenum ◽  
Columnar Cells

We have previously described the molecular cloning of a cDNA fragment synthesized from rat duodenal mRNA coding for a 9000-dalton vitamin D-induced calcium-binding protein (9-kDa CaBP) (3). We now report the use of this cloned cDNA to study the cytological distribution of 9-kDa CaBP mRNA in rat duodenum by in situ hybridization. Tissue sections, fixed in ethanol:acetic acid, were hybridized to the 3H-cDNA probe and processed for autoradiography. The specificity of the CaBP mRNA-DNA hybrid formation was checked using 3H-labeled plasmid pBR322 DNA as a control probe. 9k-Da CaBP mRNA, visualized by silver grains, was found only in the absorptive epithelial cells, and the concentration was greater in the cells at the villous tips than in those of the crypts. The 9k-Da CaBP mRNA was observed mainly in the cytoplasm of the columnar cells and less frequently in the nucleus. Labeling was not seen in the brush border and goblet cells. The submucosa, with Brunner's glands and muscularis, also showed no specific 9-kDa CaBP mRNA concentration. This demonstration of 9-kDa CaBP gene activity in the columnar cells of the rat duodenum illustrates the usefulness of in situ hybridization for characterization of specific cells involved in the expression of 1,25(OH)2 D3 activity.

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