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Ultrastructural localization of the 9-kilodalton vitamin d-dependent calcium-binding protein in the murine intraplacental yolk sac.

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THE ANATOMICAL RECORD 222~252-259(19881
Ultrastructural Localization of the 9-Kilodalton
Vitamin D-Dependent Calcium-Binding Protein in
the Murine lntraplacental Yolk Sac
Departments ofAnatomy and Cell Biology (N.H.R., N.H.l?, J.C.H.); Pathology, (M.E.H.B.,
D.E.B.); Biochemsitry (M.E.H.B.); and The Cancer Center (J.C.H.); University o f Virginia
Medical Center, Charlottesuille, Virginia 22908
The calcium-binding protein (CaBP) calbindin has been implicated
in the molecular mechanism of placental calcium transfer. Previous light microscopic
studies have identified CaBP in visceral (but not parietal) endodermal cells of the
yolk sac with the most intense immunocytochemicalsignal observed in the intraplacental yolk sac. In the present studies, electron microscopy was used to study the
localization of CaBP in placenta.
Placentas of 17-daypregnant mice were fixed by perfusion in 0.5% glutaraldehyde,
embedded in low-temperature Lowicryl K4M, and examined in thin section for specific
labeling with a polyclonal antiserum. Antibody to CaBP was localized by using protein
A-gold particles which were quantified for subcellular compartmentation by using a
Videoplan computer system. A high signal for CaBP was found in the visceral endodermal cells of the intraplacental yolk sac. In these cells, gold particles indicating
the location of CaBP were observed over 1)the cytoplasmic matrix where the average
number of gold particles per pm2was 33; 2) the microvilli (17/pm2);3)the mitochondria
(17/pm2);and 4) the nucleus (43/pm2).Sections from antigen-absorbed controls, by
contrast, showed few gold particles: cytosol, 2/pm2;microvilli, 5/pmZ; mitochondria,
5/pm2; and nucleus, 4/km2. Electron-lucent profiles of the Golgi and endoplasmic
reticulum contained no particles in the controls and a low particle count (4/pm*)in
the stained sections. Parietal endodermal cells of the intraplacental yolk sac showed
a relatively low signal for CaBP compared with the visceral endodermal cells (5
particles/pm2vs. 39). Only low numbers of gold particles were observed in trophoblasts
(6/pm2),lymphocytes (5/pm2),and erythrocytes (5/pm2).These findings indicate that
9 kd CaBP is located predominantly in cytoplasmicmatrix, nucleus, and mitochondria
within the visceral endodermal cells of the intraplacental yolk sac.
In 1966, Wasserman and Taylor first reported the
presence of a vitamin D-dependent calcium-binding
protein (CaBP or calbindin) in chick intestine. Subsequently numerous reports have shown that the highaffinity CaBP correlates with transcellular calcium
movement (Taylor, 1980; Wasserman and Fullmer,
1982). Two immunologically and genetically distinct
forms of CaBP have been described (Desplan et al.,
1983; Wilson et al., 1985; Hunziker, 1986). A 28,000dalton (28-kd) CaBP was first described in chick intestine (Taylor and Wasserman, 1967; Wasserman et al.,
1968) and a 9,000-10,000-dalton (9-kd) CaBP was first
observed in mammalian intestine (Drescher and DeLuca, 1971; Freund and Bronner, 1975; Bruns et al.,
1977;Marche et al., 1977; Gleason and Lankford, 1981).
A 28-kd CaBP similar to the avian intestinal protein is
present in high amounts in avian and mammalian brain
and kidney (Taylor and Wasserman, 1967; Taylor, 1974;
Wasserman and Fullmer, 1982; Sonnenberg et al., 1984).
the 9-kd CaBP is also found in mouse kidney (Delorme
0 1988 ALAN R. LISS. INC
et al., 1983c) and uterus (Delorme et al., 1983b). Furthermore, a 9-kd CaBP similar or identical to the intestinal one is present in rat and mouse yolk sac and
placenta (Marche et al., 1978; Bruns et al., 1978, Delorme et al., 1979, 1982, 1983a; Danan et al., 1981;
Garel et al., 1981). In addition, Tuan and Cavanaugh
(1985) have found a 57,000-dalton CaBP in the chorioallantoic placenta of the rat.
During normal mouse gestation, the 9-kd CaBP was
first noted on day 12 in the chorioallantoic placenta but
was already present on day 9 in the yolk sac. A twofold
increase in placental 9-kd CaBP was observed on day
13 (Delorme et al., 1982). During late gestation in mice
and rats both intestinal 9-kd CaBP and placental 9-kd
Received June 2, 1986; accepted April 5, 1988.
Address reprint requests to Dr. John C. Herr, Dept. of Anatomy and
Cell Biology, Box 439 Medical Center, University of Virginia, Charlottesville, VA 22908.
CaBP levels increase in parallel with the requirement
of the fetus for large amounts of calcium in order to
meet with the needs of its rapidly mineralizing skeleton
(Bruns et al., 1978, 1981). This rapid increase of CaBP
during late gestation suggests that a placental CaBP
may play a role in maternal-fetal calcium exchange
(Bruns et al., 1978).
Within the placenta, CaBP has recently been localized in the intraplacental portion of the yolk sac as
indicated by immunocytochemical staining using the
peroxidase-antiperoxidase technique on paraffinembedded material (Bruns et al., 1985). Although the
intraplacental yolk sac was described in 1892 by Duval,
the finding of a high concentration of 9-kd CaBP in this
portion of the yolk sac provides evidence for what is
perhaps the first function linked to intraplacental yolksac-transcellular calcium transport. Other workers
(Warembourg et al., 1986) have localized calbindin-D
mRNA within the placenta by in situ hybridization. In
the present study, in order to further our understanding
of the role of CaBP within the placenta and intraplacental yolk sac, the protein A-gold technique and ultrastructural morphometrics were employed t o localize
9-kd CaBP in the endodermal cells of the murine intraplacental yolk sac. This is the first ultrastructural
localization of 9-kd vitamin D-dependent CaBP. Previous reports on this protein (e.g., Bruns et al., 1985)
frequently referred to it as 10-kd CaBP; however, we
have adopted the 9-kd nomenclature in accord with advances in the field, including our amino acid sequencing
of the purified mouse protein (Yates et al., in preparation). The term calbindin-D,, recently has been proposed for the protein (Wasserman, 1985).
Pregnant Swiss Webster mice (Mus musculus) were
obtained at 7 days of gestation. After 10 days (17 days
gestation), the pregnant females were anaesthetized
with ether and laparotomized. The left ventricle was
perfused with physiological saline containing 0.5%heparin (pH 7.2, for 5 min). This was followed by perfusion
with 50 ml of a fixative consisting of 0.5%glutaraldehyde in 0.1 M Na, HP04, 0.15 M NaCl, pH 7.4 (PBS).
After perfusion, placentas were dissected out and cut
horizontally into two pieces. The piece attached to the
umbilical cord (containing intraplacental yolk sac) was
immersed into the same fixative, cut into small pieces,
and fixed for an additional 2 hours on ice. After futation,
the tissue pieces were rinsed in PBS and free aldehyde
groups were blocked by incubation in 0.5 M NH, C1 in
PBS for 1hour on ice. After further rinses in PBS, the
tissue pieces were dehydrated in a graded series of
ethanols at 4°C and embedded in LowicrylK4M at - 40°C
with U V light for polymerization (Carlemalm et al.,
1980). Polymerization was continued under U V light
for 2-3 days at room temperture. Thin sections of Lowicryl K4M on embedded tissues were cut with a diamond or glass knife and picked up on 200-mesh Formvar
carbon-coated nickel grids.
Thin sections of Lowicryl K4M-embedded placenta
were stained for CaBP by using the protein A-gold (PAg)
technique (Roth et al., 1978). Grids with the attached
thin sections were placed on a droplet of 1%ovalbumin
in PBS for 5 min at room temperature to block nonspecific binding sites. The grids-were then transferred,
without rinsing, onto drops of anti-CaBP serum for 2
hours at room temperature in a humidified chamber.
The specificity of this antiserum has been reported previously (Bruns et al., 1978). The antiserum was used
at dilution of 1:lOO in 1%ovalbumin-PBS (pH 7.4). The
sections were washed in three changes of PBS for 10
min and were placed on drops of 1:20 dilution of PAg
(protein A conjugated to 20-nm gold particles) in PBS
for 1 hour at room temperature in a humidified chamber. The grids were then washed for 1 min in PBS and
immersed for 5 min in PBS in porcelain depression
dishes. After washing several times in PBS and distilled
water, the thin sections were examined with a Philips
301 electron microscope. Some sections were counterstained with uranyl acetate (7 min) and lead citrate (30
sec) prior to examination. The following controls were
performed to test the specificity of the immunostaining
obtained with the PAg technique: 1)replacement of the
anti-CaBP by absorbed anti-CaBP serum; 2) replacement of the antiserum by diluted normal rabbit serum;
3) omission of the antiserum and application of the PAg
solution alone; and 4) replacement of anti-CaBP by
ovalbumin in PBS.
The intensity of immunostaining was expressed as
the number of gold particles per square micrometer of
the total cell, microvilli, mitochondria, electron-lucent
luminal profiles of the endoplasmic reticulum and Golgi,
cytoplasm, and nucleus. Twenty micrographs were scored
for each type of cell studied. The types included trophoblasts (Tl, T2, and T3; Enders, 1965; Bjorkman, 1970)
lining the maternal blood spaces, erythrocytes and lymphoctes within maternal and fetal vessels, and visceral
and parietal yolk sac endoderm in the sinuses of Duval.
Measurements of subcellular compartments in visceral
yolk sac endoderm were made by tracing the limiting
membrane of cells, nuclei, microvilli, and mitochondria.
Electron-lucent domains within the cytoplasm representing membrane profiles of endoplasmic reticulum
and Golgi were also traced. These are referred t o in
tables as the lumen of the “electron-lucent reticulum”
(ER lumen). For the microvillar compartment, gold particles in contact with the microvillar surface or within
the cytoplasmic core of microvilli were scored. Data were
digitized into a Videoplan Computer System (Zeiss,West
Germany) by using a computer graphics tablet (Zeiss).
From these tracings, cross-sectional area computations
were digitized. The Videoplan computer software option
“Area” was selected for acquisition of data.
The intraplacental yolk sac of the 17-day-pregnant
mouse consists of invaginations of both parietal and
visceral yolk sac which accompany the branching umbilical vessels into the chorioallantoic placenta. Seen in
low-power electron micrographs (Fig. 1), the parietal
portion of the intraplacental yolk sac demonstrated a
thick Reichert’s membrane on which squamous endodermal cells containing large nuclei were situated. In
places, the parietal endoderm did not form a continuous
sheet over Reichert’s membrane. The visceral portion
of the intraplacental yolk sac was composed of columnar
endodermal cells which displayed intercellular clefts.
Following immunostaining, protein-A gold particles
in the endodermal cells of the intraplacental yolk sac,
in trophoblast cells (termed TI, T, and T3),in-lympho:
Fig. 1. Electron micrograph of intraplacental yolk sac showing the
columnar visceral endodermal cells (V), sinus of Duval (S.D.), and the
parietal endodermal cells (P) resting on Reichert’s membrane (R). The
lateral borders of the visceral endodermal cells display intracellular clefts
(IC). Below Reichert’s membrane part of the trophoblasts (TI line a
maternal blood space (M.B.S.). Uranyl acetate and lead citrate counterstain. x 7,411.
cytes, and in erythrocytes were quantified by computerized morphometrics, and results on the relative
distribution of gold particles in these cell types were
compared (Fig. 2). Visceral endodermal cells of the intraplacental yolk sac contained the highest number of
gold particles (39/km2).The other types of cells studied
show a relatively low number of particles, being 5/km2
in the parietal endodermal cells of the intraplacental
yolk sac, 6/pm2 in the trophoblasts, and 5/km2 in the
erythrocytes. The number of gold particles in these cells
Anti - CaBP
Antigen - Absorbed
Anti CaBP (Control)
atively less labeling (Fig. 4). The control sections, in
which the incubation with antiserum was replaced by
antigen-absorbed anti-CaBP or controls which assessed
the binding of PAg alone, showed gold particle distributions as follows: microvilli 5/pm2,the cytoplasm (cytosol) 2/pm2,the mitochondria 5/pm2, and the nucleus
4/pm2 (Fig. 4). Results obtained from control sections
prepared by omission of the antiserum and application
of the PAg solution alone showed 1particle/pmZ in microvilli; 2/pm2in cytosol; 0.44/pm2in mitochondria; and
0.6/pm2in nucleus. In both controls, the electron-lucent
cytoplasmic profiles contained no particles. An example
of the apical microvillar surface of the visceral endodermal cells reacted with anti-CaBP is presented in
Figure 3c, where gold particles in association with the
microvilli may be noted.
Fig.2. F’rotein A-coated gold particles binding to several placental cell
types quantitated per unit area (pmz).Tissue sections were first incubated with anti-CaBP (cross-hatched) or control serum (open bars). The
error bars indicate 1 standard deviation.
was significantly lower than those found in the visceral
endodermal cells. However, the number of gold particles in these different types of cells exceeded gold particle densities in the CaBP-absorbed controls (Fig. 2).
In Figure 3a and b, the distribution of gold particles
in immunochemically stained sections of visceral endodermal cells, the cell type with the highest signal for
CaBP (Fig. 3a), may be compared with that in the antigen-absorbed control (Fig. 3b). Although fixation with
glutaraldehyde concentrations greater than 1% and
postifuration osmication destroyed antigenicity of CaBP,
the tissues were preserved sufficiently in 0.5% glutaraldehyde to detect on the electron micrographs the
membrane boundaries of the nucleus, mitchondria, and
the profiles of endoplasmic reticuludGolgi, despite the
absence of osmium (see Fig. 3a or c). Quantitative evaluation of gold particle labeling for CaBP in subcellular
compartments of the visceral endodermal cells, including microvilli, cytosol, mitochondria, electron-lucent cytoplasmic profiles (Golgi and ER), and nucleus, was
performed (Fig. 4). Within the visceral endodermal cells,
the nucleus, especially the euchromatin, contained the
greatest number of gold particles (43/pm2),followed by
the cytoplasmic matrix (cytosol)(33/pm2),while the mitochondria (17/pm2)and microvilli (17/pm2)showed rel-
We previously observed immunolabelling for vitamin
D-dependent CaBP in the columnar endodermal cells
of the intraplacental yolk sac lining the sinuses of Duval
with peroxidase-antiperoxidase labelling of paraffinembedded placental tissue (Bruns et al., 1985). In that
study, immunostaining for CaBP was also observed
within the extraplacental yolk sac in the columnar
endoderm of the villous yolk sac, a finding which confirmed the observations of Delorme et al. (1983a).Based
upon light microscopic observations of DAB reaction
product, however, the columnar endoderm of the intraplacental yolk sac gave the most intense staining of all
regions of yolk sac endoderm observed in 16-17-day
mouse placentas, suggesting that calcium transport may
be an important function for intraplacental yolk sac
during this period. The present ultrastructural study,
employing the protein A-gold technique coupled to
quantitative morphometry, emphasized the ultrastructural localization of CaBP specifically withing the endoderm of the murine intraplacental yolk sac.
Unosmicated, unstained tissue fixed in a reduced concentration of glutaraldehyde was employed because both
osmication and glutaraldehyde concentrations > 1%destroyed CaBP antigenicity.
The gold labeling which we employed renders possible the localization of antigenic sites in organelles
with inhomogeneous electron density; and it allows an
indirect estimation of the number of antigenic sites in
the various subcellular compartments (Roth et al., 1980,
1981). Thin sections were prepared by using low-temperature embedding Lowicryl (Carlemalm et al., 1982).
Douzou (1977) has shown that a t low temperatures enzymes resist denaturation in organic solvent solutions.
Also, low-temperature embedding conditions minimize
alterations of the tertiary structure of crystalline biological materials (Garavito et al., 1980) With low-temperature embedding medium and the protein A-gold
technique, the present results revealed a significant
signal of gold particles in the intraplacental yolk sac
visceral endodermal cells, while the other types of the
cells of the placenta showed a lower level of staining
quantitatively similar to the controls of the visceral
endodermal cells. Comparing the number of particles
in specifically labeled sections with their controls, signallnoise ratios of 1:10 were obtained in the visceral
endodermal cells, 1:6 in the parietal cells, and 1:4 in
the trophoblasts, lymphocytes, and erythrocytes.
Fig. 3. a: Electron micrograph demonstrating the distribution of 20nm protein A-gold particles in visceral endodermal cells of the intraplacental yolk sac after anti-CaBP serum. Concentrations of gold particles
are noted over nucleus, cytoplasm, within mitochondria, and over microdli (arrows). Several membrane-bounded electron-lucent regions of
cytoplasm are noted with asterisks. No counterstain. x 35,792. b: Electron micrograph of a control section showing a portion of a visceral
endodermal cell treated with absorbed anti CaBP serum. The visceral
endodermal cell contains few gold particles distributed nonspecifically
over the cell. No gold particles are associated with microvilli (arrows).
No counterstain. ~47,692.c: Higher magnification of the apex of a
visceral endoderm cell with microvilli bordering the sinus of Duval. Gold
particles indicating the immunolocalization of CaBP within the cores of
microvilli are evident (arrows). Asterisks are placed in the lumena of
several membrane-bounded compartments. x 102,354. M = mitochondria.
Although the number of antigenic sites detected in
cell types other than visceral endoderm was quantitatively similar to the visceral endoderm controls, these
other cells types demonstrated a postive signal higher
than their control values. This signal in cell types other
than visceral endoderm might be due to one of the following: 1) diffusion of CaBP from the visceral endodermal cells to the other types of cells during the
preparation procedure. (The extracellular spaces contain approximately the same percentage of gold particles per pm2 as the parietal endoderm, trophoblasts,
lymphocytes and erythrocytes [data not shown].)2) Each
of these other cell types, as well as the extracellular
space, may indeed have a low level of CaBP in situ.
Previous light immunocytochemical studies using the
peroxidase-antiperoxidasemethod (Bruns et al., 1985)
on paraffin-embedded material did not detect any signal for CaBP in cell types other than visceral yolk-sac
endoderm. (Visceral endoderm of both intra- and extraplacental yolk sac was positive.) Lower sensitivity
of the PAP method in paraffin material may have precluded detection of positive signal in the other nonendodermal placental cell types.
The number of gold particles per pm2 in the controls
of visceral endodermal cells was higher than their number in the controls of the other types of cells. This suggests that a small amount of immunoreactivity may
have remained in the antigen-absorbed antiserum control.
Within the visceral endodermal cells of the intraplacental yolk sac gold particles were shown to be present
over the cytoplasmic matrix. Gold particles were observed infrequently within the electron-lucent lumen
of the endoplasmic reticulum or within cellular vesicles
and were not a t levels signficantly above background.
The mitochondria contained CaBP at levels significantly above controls. The presence of gold particles in
the cytoplasmic matrix suggests synthesis of 9-kd CaBP
on the free ribosomes of the intraplacental yolk sac
endoderm, consistent with the previous biochemical
(Emtage et al., 1973; Spencer et al., 1976, 1978; Christakos and Norman, 1980) and ultrastructural data
(Thorens et al., 1982) on the synthesis of 28-kd CaBP
in chicken intestinal epithelium. The mitochondria1localization of vitamin D-dependent 9-kd CaBP observed
in the present study has not previously been reported.
Anti- CaBP
ies have shown that the rat yolk sac in vitro (Kernics
and Johnson, 1969) and in vivo (Delorme et al., 1982)
is able to transport Ca2 from the maternal to the fetal
Comparison of the distribution of gold particles in
visceral vs. parietal endodermal cells of the intraplacental yolk sac showed an eightfold-higher signal per
square micron in the visceral endodermal cells. This
asymmetry in CaBP distribution within these structurally different endodermal cell types is of interest.
The parietal endodermal cells rest on a thick Reichert's
membrane, whereas the basement membrane beneath
the visceral endoderm is thinner. Further, the visceral
endodermal cells lie adjacent to fetal chorionic vessels,
the possible route for calcium returning from the placenta to the developing fetus. Since the sinuses of Duval
are continuous with the uterine lumen following inversion of the yolk sac, it may be speculated that calcium
in the sinus is actively absorbed by the apical surface
of the visceral endodermal cells.
Delorme et al. (1983a), using immunocytochemical
techniques and light microscopy, found no 9-kd CaBP
in the nucleus or on the external surface projections of
the endodermal cells of the visceral yolk sac of rat. In
contrast to the previous report, the present study at
the electron microscopic level showed that the nucleus
of the visceral cells of the intraplacental yolk sac is
characterized by a high level of gold particles. Although
euchromatin and heterochromatin were not quantitated separately it appeared that euchromatin had the
higher density of gold particles. Thorens et al. (1982)
also found localizations of 28-kd CaBP in the euchromatin of the nucleus of chick duodenal cells. The high
concentration of both 28-kd and 9-kd CaBPs in both the
cytoplasm and the nucleus may indicate that Cal3P plays
a role in the intracellular regulation of Ca2+concentration in both the nuclear and cytoplasmic compartments
in the intraplacental yolk sac endoderm, in addition to
its possible involvement in the transport of Ca2+from
mother to fetus.
Antigen- Absor bed
Anti - CaBP (Control)
Fig. 4. The number of gold particles per unit area (pm2)w i t h various
compartments of the visceral endodermal cells of the intraplacental yolk
sac of experimental and controls. Error bars indicate 1 standard deviation.
Thorens and co-workers (1982) did not report a mitochondrial localization for the 28-kd CaBP found in cells
Supported by NIH grants HD 12335 and HD17489
such as the duodenal epithelial cells of the chicken and a fellowship from the Binational Fulbright Com(Thorens et al., 1982). This mitochondria1 localization mission (N.H.R.).
is a unique finding for 9-kd CaBP.
Thorens et al. (1982) reported that their immunocytochemical results on subcellular localization of in- Bjorkman, N. 1970 An Atlas of Placental Fine Structure. Williams and
testinal 28-kd Cal3P did not support a role of this vitamin
Wilkins, Baltimore.
D-dependent protein in the initial uptake and move- Bruns, M.E.H., A. Fausto, and L.V. Avioli 1978 Placental calcium binding
protein in rats. Apparent identity with vitamin D-dependent calcium
ment of Ca2' across the brush border membrane of the
binding protein from rat intestine. J. Biol. Chem., 253t3186-3190.
epithelial cell as has been suggested by light micro- Bruns, M.E., E.B. Fleisher, and L.V. Avioli 1977 Control of vitamin Dscopic (Taylor and Wasserman, 1970) and biochemical
dependent calcium-binding protein in rat mtestine by growth and
fasting. J. Biol. Chem., 252t4145-4150.
studies (Ebel et al., 1969; Emtage et al., 1974; Corradin0 et al., 1976). Marche et al. (1980) found 9-kd CaBP Bruns, M.E.H., E. Kleeman, S.E. Mills, D.E. Bruns, and J. Herr 1985
Immunocytochemical localization of vitamin D-dependent CaBP in
associated with the terminal web of rat duodenal abmouse placenta and yolk sac. Anat. Rec., 213:514-517.
sorptive epithelial cells a t the light level. The present Bruns, M.E.H., S. Vollmer, V. Wallshein, and D.E. Bruns 1981 Vitamin
D-dependent calcium-binding protein, immunochemical studies and
study revealed the presence of 9-kd CaBP in the misynthesis by placental tissue in vitro. J. Biol. Chem., 2564649-4653.
crovilli of the visceral endodermal cells of the intraplaE., M. Garavile, and W. ViUiger 1982 Resin development
cental yolk sac as indicated by the number of particles Carlemalm,
for electron microscopy and a n analysis of embedding at low temappearing on the microvillous membrane or in the core
perature. J. Microsc., 126:123-143.
of microvilli as seen in electron micrographs (17/pm2in Carlemalm, E., W. Vilhger, and J.D. Acetarin 1980Advances in specimen
preparation for electron microscopy. I. Novel low temperature ernbedexperimentals versus l/pmz in controls). This finding
dmg resins and reformulated vestopal. Experientia, 36:740.
indicates a possible role of microvilli-associated 9-kd Christakos,
S., and A.W. Norman 1980 Apparent messenger RNA acCaBP in the transport of Ca2+from the maternal to the
tivity for vitamin D-dependent calcium binding protein in chick kidney and duodenum. Arch. Biophys., 203t809-815.
fetal compartment of the murine placenta. Earlier stud-
Corradino, R.A., C.S. Fullner, and R.H. Wasserman 1976 Embryonic
protein, a protein indicator of enterocyte maturation associated with
chick intestine in organ culture: Stimulation of calcium transport by
the terminal web. Cell Tissue Res., 212t63-72.
exogenous vitamin D-induced calcium binding protein. Arch. Biochem. Marche, P., A. DeLorme, and P. Cuisinier Gleizes 1978 Intestinal and
Biophys., 174:738-743.
placental calcium binding protein in vitamin D-deprived or supplemental rats. Life Sci., 23:2555-2562.
Danan, J.L., A.C. Delorme, and P. Cuisinier-Gleizes 1981 Biochemical
evidence for a cytoplasmic la, 25-dihydroxyvitamin D, receptor-like Marche, P., P. Pradelles, C. Gross, and M. Thomasset 1977 Radioimprotein in rat yolk sac. J. Biol. Chem., 256:4847-4850.
munoassay for a vitamin-D dependent calcium binding protein in rat
Delorme, A.C., P. Cassier, B. Geng, and H. Mathieu 1983a Immunocydudodenal mucosa. Biochem. Biophys. Res. Commun., 76:102&1025.
tochemical localization of vitamin D-dependent calcium binding pro- Roth, J., M. Bendayan, and L. Orci 1978 Ultrastructural localization of
tein in the yolk sac of the rat placenta. Placenta, 4:263-270.
intracellular antigens by the use of protein A-gold complex. J . HisDelorme, A.C., J.L. Danan, M.G. Archer, M.A. Ripoche, and H. Mathieu
tochem. Cytochem., 26:1074-1081.
1983b In rat uterus 17B-estradiol stimulates a calcium-binding pro- Roth, J., M. Bendayan, and L. Orci 1980 FITC-protein A-gold complex
tein similar to the duodenal vitamin D-dependent calcium-binding
for light- and electron microscopic immunocytochemistry. J. Histoprotein. Endocrinology, 113:1340-1347.
chem. Cytochem., 28:55-57.
Delorme, A.C., J.L. Danan, and H. Mathieu 1983c Biochemical evidence Roth, J., M. Ravazzola, M. Bendayan, and L. Orci 1981 Application of
for the presence of two vitamin D-dependent calcium-binding prothe protein-A-gold technique for electron microscopic demonstration
teins in mouse kidney. J . Biol. Chem., 258:1878-1884.
of polypeptide hormones. Endocrinology, 108:247-253.
Delorme, A.C., J.L. Danan, M.A. Ripoche, and H. Mathieu 1982 Biochem- Sonnenberg, J., A.R. Dansini, and S. Christakos 1984 Vitamin D-deical characterization of mouse vitamin D-dependent calcium-binding
pendent rat renal calcium-binding protein: Development of a radioimmunoassay, tissue distribution and immunologic identification.
protein. Biochem. J.,205:49-57.
Endocrinology, 115:640-648.
Delorme, A.C., P. Marche, and J.M. Garel 1979 Vitamin-D dependent
calcium binding protein. Changes during gestation, prenatal and Spencer, R., M. Charman, P.W. Wilson, and D.E.M. Lawson 1976 Vipostnatal development in rats. J. Dev. Physiol., 1:181-194.
tamin-D stimulated intestinal calcium absorption may not involve
Desplan, C., 0. Heidmann, J.W. Lillie, C. Auffray, and M. Thomasset
calcium binding protein directly. Nature (Land.), 263:161-163.
1983 Sequence of rat intestinal vitamin D-dependent calcium-bind- Spencer, R., M. Charman, P.W. Wilson, and D.E.M. Lawson 1978 The
ing protein derived from a cDNA clone. J. Biol. Chem., 258:13502relationship between vitamin D-stimulated transport and intestinal
calcium-binding protein in chicken. Biochem. J., 170t93-101.
Douzou, P. 1977 Enzymology at sub-zero temperatures. Adv. Enzymol., Talyor, A.N. 1974 Chick brain calcium-binding protein: Comparison with
intestinal vitamin D-induced calcium-binding proteins. Arch. Biochem.
Biophys., 161:lOO-108.
Drescher, D., and H.F. DeLuca 1971 Vitamin D stimulated calcium
binding protein from rat intestinal mucosa. Purification and some Taylor, A.N. 1980 Vitamin D dependent calcium binding proteins. In:
Vitamin D Molecular Biology and Clinical Nutrition. A.W. Norman,
properties. Biochemistry, 10:2302-2307.
ed. Marcel Dekker, New York, pp. 321-351.
Ebel, J.G., A.N. Taylor, and R.H. Wasserman 1969 Vitamin D-induced
calcium binding protein of intestinal mucosa. Relation to vitamin D Taylor, A.N., and R.H. Wasserman, 1967 Vitamin D,-induced calciumbinding protein: Partial purification, electrophoretic visualization,
dose level and lag period. Am. J . Clin. Nutr., 22:431-436.
and tissue distribution. Arch. Biochem. Biphys., 119.536-540.
Emtage, J.S., D.E.M. Lawson, and E. Kodicek 1973 Vitamin D-induced
synthesis of FWA for calcium binding protein. Nature (Land.), Taylor, A.N., and R.H. Wasserman 1970 Immunofluorescent localization
of vitamin D-dependent calcium binding proteins. J . Histochem. Cy246:100-101,
tochem., 18:107-115.
Emtage, J.S., D.E.M. Lawson, and E. Kodicek 1974 The response of the
small intestine to vitamin D. Correlation between calcium-binding Thorens, B., J. Roth, A.W. Norman, A. Perrelet, and L. Orci 1982 Immunocytochemical localization of the vitamin D-dependent calcium
protein production and increased calcium absorption. Biochem. J.,
binding protein in chick duodenum. J. Cell Biol., 94:115-122.
Enders, A.C. 1965 A comparative study of the fine structure in several Tuan, R.S., and S.T. Cavanaugh, 1985 Identification and characterizahemochorial placentas. Am. J . h a t . , 116t29-67.
tion of a calcium-binding protein in the mouse chorioallantoic placenta. Biochem. J., 233:41-49.
Freund, J.,and F. Bronner 1975 Regulation of intestinal calcium binding
protein by calcium intake in the rat. Am. J . Physiol., 228:861-869.
Waremburg, M., C. Perret, and M. Thomasset 1986 Distribution of
Garavito, R.M., W. Villiger, and E. Carlemalm 1980 Advances in specvitamin D-dependent calcium binding protein messenger ribonucleic
imen preparation for electron microscopy. 11. Structural preservation
acid in rat placenta and duodenum. Endocrinology. 119t176-184.
in crystalline biological material. Experientia, 36:745.
Wasserman, R.H. 1985 Nomenclature of the Vitamin D induced calcium
Garel, J.M., AC. Delorme, P.N. Marche, T.M. Guyen and M. Garabedian
binding proteins. In: Vitamin D: Chemical, Biochemical and Clinical
1981 Vitamin D, metabolite injections to thyroparathyroidectomized
Update. A.W. Norman, K. Schaefer, H.G. Grigoleit, and D.V. Herrath,
pregnant rats: Effects on calcium binding proteins of maternal duoeds. DeGruyter, Berlin, pp. 321-322.
denum and of feto-placental unit. Endocrinology, 109.284-289.
Wasserman, R.H., R.A. Corradino, and A.N. Taylor 1968 Vitamin DGleason, W.A., and G.L. Lankford 1981 Rat intestinal calcium binding
dependent calcium protein: Purification and some properties. J. Biol.
protein: Rapid purification with AG MP-1 ion exchange chromatogChem., 243:3978-3986.
raphy. Anal. Biochem., 116:256-263.
Wasserman, R.H., and C.S. Fullmer 1982 Vitamin D-induced calciumHunziker, W. 1986 The 28-kDa vitamin D-dependent calcium-binding
binding protein. In: Calcium and Cell Function, Vol. 2. W.Y. Cheung,
protein has a six-domain structure. Proc. Natl. Acad. Sci. USA,
ed. Academic Press, New York, pp. 191-216.
Wasserman, R.H., and A.N. Taylor 1966 Vitamin D,-induced calciumbinding protein in chick intestinal mucosa. Science, 152:791-793.
Kernics, M.M., and E.M. Johnson 1969 Effects of trypan blue and Niagra
Wilson, P.W., M. Harding, and D.E.M. Lawson 1985 Putative amino acid
blue 2B on the in vitro absorption of ions by the rat visceral yolk
sequence of chick calcium-binding protein deduced from a complesac. J . Embryol. Exp. Morphol. 22:115-125.
mentary DNA sequence. Nucleic Acids Res., 13:8867-8881.
Marche, P., P. Cossier, and M. Mathieu 1980 Intestinal calcium-binding
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ultrastructure, kilodalton, vitamins, murine, protein, localization, sac, dependence, calcium, intraplacental, binding, yolk
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