scholarly journals Immunohistochemical characterization of a differentiation-specific carbohydrate epitope in the plasma membrane of the epithelial cells of rat small intestine.

1993 ◽  
Vol 41 (1) ◽  
pp. 71-79 ◽  
Author(s):  
H Schiechl
Keyword(s):  
Small Intestine ◽  
Plasma Membrane ◽  
Epithelial Cells ◽  
Basolateral Membrane ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Lateral Part ◽  
Rat Small Intestine ◽  
Electron Microscopic

The monoclonal antibody (MAb) SI/EC1 was produced by immunization of Balb/c mice with an antigen prepared from the isolated basolateral membrane (BLM) of rat small intestine epithelial cells by trypsin cleavage. Immunohistochemical labeling at the light and electron microscopic level shows that the SI/EC1 epitope is localized in the plasma membrane (PM) of the small intestine epithelial cells and is expressed around Day 21 after birth (weaning time). There are, however, differences in the labeling between crypt and villous cells. In the crypt cells, the microvillous membrane (MVM) and the lateral part of the BLM are strongly labeled, whereas the basal part of the BLM is unlabeled. In the villous cells, both the MVM and the basal and lateral part of the BLM are labeled, but the labeling is not as intense as in the crypts. In immunoblotting experiments with the isolated BLM, three protein bands (125 KD, 110 KD, and 90 KD) were labeled specifically with the MAb. Enzymic cleaving of the BLM with exo- and endoglycosidases and subsequent immunoblotting, as well as other findings, suggest that the specific structure of the SI/EC1 epitope consists mainly of carbohydrates (CH) (oligosaccharides). This finding points out the possibility that this epitope may have something to do with the variable adhesion of the small intestine epithelial cells along the crypt-villus axis.

scholarly journals Ultrastructural localization of guanylate cyclase in bone cells.

1991 ◽  
Vol 39 (4) ◽  
pp. 529-535 ◽  
Author(s):  
O Fukushima ◽  
C V Gay
Keyword(s):  
Plasma Membrane ◽  
Guanylate Cyclase ◽  
Bone Cells ◽  
Ultrastructural Localization ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Lead Citrate ◽  
Free Medium ◽  
Membrane Guanylate Cyclase ◽  
Electron Microscopic

Guanylyl imidodiphosphate (GMP-PNP) hydrolyzing enzyme activity as a means of detecting plasma membrane guanylate cyclase was demonstrated in osteoblasts of chicken tibial metaphysis using a lead citrate histochemical method at the electron microscopic level. Activity was not discerned in osteoclasts or osteocytes. The reaction product development was completely abolished when the sections were incubated with substrate-free or MnCl2-free medium. Guanylate-(beta, gamma-methylene) diphosphate (GMP-PCP) was a less effective substrate than GMP-PNP, and Mn++ was a stronger stimulator than Mg++. No reaction product was observed on the plasma membrane of osteoblasts when beta-glycerophosphate or p-nitrophenylphosphate was used as substrate instead of GMP-PNP. The results implicate guanylate cyclase as a significant effector of osteoblast regulation at the site of the plasma membrane.

Immunochemical localization of amiloride-sensitive sodium channels in sodium-transporting epithelia

1989 ◽  
Vol 93 (2) ◽  
pp. 349-362 ◽  
Author(s):  
A. Tousson ◽  
C.D. Alley ◽  
E.J. Sorscher ◽  
B.R. Brinkley ◽  
D.J. Benos
Keyword(s):  
Short Circuit ◽  
Basolateral Membrane ◽  
Chinese Hamster ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Apical Plasma Membrane ◽  
Na Channel ◽  
Electron Microscopic ◽  
Specific Staining ◽  
Channel Protein

The localization of amiloride-sensitive Na+ channels in Na+-transporting epithelia was examined using antibodies made against amiloride-binding Na+ channel protein purified from bovine kidney. The distribution of the channel protein was determined in thick frozen sections at the light-microscopic level using indirect immunofluorescence, and at the electron-microscopic level using immunogold labelling. In the cells of both the intact bovine collecting tubule and A6 confluent monolayers, only the luminal or apical-facing surface membranes showed staining. Sodium channel protein was characteristically localized on microvillar domains of the apical plasma membrane. Little or no basolateral membrane staining was evident. Channel protein was also absent from subapical vesicles and tight junctions, and was not found in bovine renal proximal tubules, cultured human secretory sweat coils, non-epithelial Chinese hamster ovary (CHO) cells or human skin fibroblasts. Trypsinization of intact A6 monolayers prior to cell fixation abolished specific staining with antibody. Pretreatment with amiloride protected against this loss of staining. Thus, our probes are specific for amiloride-binding Na+ channel protein, and this channel protein is largely or completely confined to the apical membrane of Na+-transporting epithelia. The level and distribution of specific immunostaining in A6 cells was unchanged by aldosterone treatment, although channel activity, as measured by short-circuit current, increased threefold. This result demonstrates that Na+ channel protein is ever present at the cell surface and exists in both an active and an inactive form. We find no evidence that stimulation of Na+ uptake by aldosterone involves recruitment of new channels from a cytoplasmic pool.

scholarly journals Cellular and Subcellular Localisation of Kv4-Associated KChIP Proteins in the Rat Cerebellum

2020 ◽  
Vol 21 (17) ◽  
pp. 6403
Author(s):  
Rocío Alfaro-Ruíz ◽  
Carolina Aguado ◽  
Alejandro Martín-Belmonte ◽  
Ana Esther Moreno-Martínez ◽  
Rafael Luján
Keyword(s):  
Plasma Membrane ◽  
Purkinje Cells ◽  
Granule Cells ◽  
Distribution Patterns ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
K Channel ◽  
Subcellular Localisation ◽  
Electron Microscopic ◽  
Parallel Fibres

The K+ channel interacting proteins (KChIPs) are a family of cytosolic proteins that interact with Kv4 channels, leading to higher current density, modulation of channel inactivation and faster recovery from inactivation. Using immunohistochemical techniques at the light and electron microscopic level combined with quantitative analysis, we investigated the cellular and subcellular localisation of KChIP3 and KChIP4 to compare their distribution patterns with those for Kv4.2 and Kv4.3 in the cerebellar cortex. Immunohistochemistry at the light microscopic level demonstrated that KChIP3, KChIP4, Kv4.2 and Kv4.3 proteins were widely expressed in the cerebellum, with mostly overlapping patterns. Immunoelectron microscopic techniques showed that KChIP3, KChIP4, Kv4.2 and Kv4.3 shared virtually the same somato-dendritic domains of Purkinje cells and granule cells. Application of quantitative approaches showed that KChIP3 and KChIP4 were mainly membrane-associated, but also present at cytoplasmic sites close to the plasma membrane, in dendritic spines and shafts of Purkinje cells (PCs) and dendrites of granule cells (GCs). Similarly, immunoparticles for Kv4.2 and Kv4.3 were observed along the plasma membrane and at intracellular sites in the same neuron populations. In addition to the preferential postsynaptic distribution, KChIPs and Kv4 were also distributed presynaptically in parallel fibres and mossy fibres. Immunoparticles for KChIP3, KChIP4 and Kv4.3 were detected in parallel fibres, and KChIP3, KChIP4, Kv4.2 and Kv4.3 were found in parallel fibres, indicating that composition of KChIP and Kv4 seems to be input-dependent. Together, our findings unravelled previously uncharacterised KChIP and Kv4 subcellular localisation patterns in neurons, revealed that KChIP have additional Kv4-unrelated functions in the cerebellum and support the formation of macromolecular complexes between KChIP3 and KChIP4 with heterotetrameric Kv4.2/Kv4.3 channels.

scholarly journals A Morphometric Analysis of Nucleoli in Cultured Carcinoma Cells of the Human Thyroid

1998 ◽  
Vol 16 (3) ◽  
pp. 131-140 ◽  
Author(s):  
Lars Andersen ◽  
Lars Kayser ◽  
Niels Keiding ◽  
Jens Thomsen
Keyword(s):  
Epithelial Cells ◽  
Thyroid Carcinoma ◽  
Thyroid Tissue ◽  
Microscopic Level ◽  
Carcinoma Cells ◽  
Electron Microscopic Level ◽  
Human Thyroid ◽  
Electron Microscopic ◽  
Normal Thyroid ◽  
Granular Component

Cells from 7 patients operated on for thyroid cancer were investigated. Samples of cells from the carcinoma and from the normal thyroid tissue were cultured with and without TSH stimulation. For light microscopy, serial sections of cells were cut and the size of nucleoli was measured and the number of nucleoli per cell counted. At the electron microscopic level the number and the volume of the fibrillar centres (FC) were estimated taking the Swiss cheese effect into account. The areal densities of FC, the fibrillar and granular component in nucleoli were determined by point counting. The results indicate that the malignant transformation has no influence on the size of the FC, but the observed numbers as well as the total area of FC are larger in cancer cells than in the normal thyroid epithelial cells. The nucleolar density of the fibrillar component is larger and that of the granular component is smaller in thyroid carcinoma cells than in non‐malignant thyroid epithelial cells (p= 0.0001). Thus simple morphometry at the electron microscopic level might be helpful to discriminate between thyroid epithelial cells and thyroid carcinoma cells in culture.

A simplified method of emulsion coating and development for quantitative electron microscopic radioautography

1978 ◽  
Vol 36 (2) ◽  
pp. 64-65
Author(s):  
K. Yoshida ◽  
F. Murata ◽  
S. Ohno ◽  
T. Nagata
Keyword(s):  
Mass Production ◽  
Identical Condition ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Simplified Method ◽  
Complicated Process ◽  
Critical Problems ◽  
Electron Microscopic Radioautography ◽  
Quantitative Radioautography

IntroductionSeveral methods of mounting emulsion for radioautography at the electron microscopic level have been reported. From the viewpoint of quantitative radioautography, however, there are many critical problems in the procedure to produce radioautographs. For example, it is necessary to apply and develop emulsions in several experimental groups under an identical condition. Moreover, it is necessary to treat a lot of grids at the same time in the dark room for statistical analysis. Since the complicated process and technical difficulties in these procedures are inadequate to conduct a quantitative analysis of many radioautographs at once, many factors may bring about unexpected results. In order to improve these complicated procedures, a simplified dropping method for mass production of radioautographs under an identical condition was previously reported. However, this procedure was not completely satisfactory from the viewpoint of emulsion homogeneity. This paper reports another improved procedure employing wire loops.

X-Ray Microanalysis of Nickel and Cobalt Intensified Peroxidase- Antiperoxidase For Verification of Reaction Sites

1985 ◽  
Vol 43 ◽  
pp. 468-469
Author(s):  
A. Angel ◽  
K. Miller ◽  
V. Seybold ◽  
R. Kriebel
Keyword(s):  
Reaction Mechanisms ◽  
Visual Discrimination ◽  
Osmium Tetroxide ◽  
Ultrastructural Level ◽  
Microscopic Level ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
X Ray ◽  
Insoluble Polymer ◽  
Cytochemical Reaction

Localization of specific substances at the ultrastructural level is dependent on the introduction of chemicals which will complex and impart an electron density at specific reaction sites. Peroxidase-antiperoxidase(PAP) methods have been successfully applied at the electron microscopic level. The PAP complex is localized by addition of its substrate, hydrogen peroxide and an electron donor, usually diaminobenzidine(DAB). On oxidation, DAB forms an insoluble polymer which is able to chelate with osmium tetroxide becoming electron dense. Since verification of reactivity is visual, discrimination of reaction product from osmiophillic structures may be difficult. Recently, x-ray microanalysis has been applied to examine cytochemical reaction precipitates, their distribution in tissues, and to study cytochemical reaction mechanisms. For example, immunoreactive sites labelled with gold have been ascertained by means of x-ray microanalysis.

Region-dependent disappearance of vinblastine in rat small intestine and characterization of its P-glycoprotein-mediated efflux system

2000 ◽  
Vol 11 (4) ◽  
pp. 317-324 ◽  
Author(s):  
Akira Nakayama ◽  
Hiroshi Saitoh ◽  
Masako Oda ◽  
Masahiko Takada ◽  
Bruce J Aungst
Keyword(s):  
Small Intestine ◽  
Rat Small Intestine ◽  
Efflux System ◽  
P Glycoprotein

scholarly journals (Na+ + K+)-ATPase and plasma membrane polarity of intestinal epithelial cells: presence of a brush border antigen in the distal large intestine that is immunologically related to beta subunit.

1989 ◽  
Vol 109 (3) ◽  
pp. 1057-1069 ◽  
Author(s):  
A Marxer ◽  
B Stieger ◽  
A Quaroni ◽  
M Kashgarian ◽  
H P Hauri
Keyword(s):  
Monoclonal Antibody ◽  
Small Intestine ◽  
Epithelial Cells ◽  
Brush Border ◽  
Basolateral Membrane ◽  
Apical Cell ◽  
Distal Colon ◽  
Proximal Colon ◽  
Beta Subunit ◽  
Cell Pole

The previously produced monoclonal antibody IEC 1/48 against cultured rat intestinal crypt cells (Quaroni, A., and K. J. Isselbacher. 1981. J. Natl. Cancer Inst. 67:1353-1362) was extensively characterized and found to be directed against the beta subunit of (Na+ + K+)-ATPase as assessed by immunological and enzymatic criteria. Under nondenaturing conditions the antibody precipitated the alpha-beta enzyme complex (98,000 and 48,000 Mr). This probe, together with the monoclonal antibody C 62.4 against the alpha subunit (Kashgarian, M., D. Biemesderfer, M. Caplan, and B. Forbush. 1985. Kidney Int. 28:899-913), was used to localize (Na+ + K+)-ATPase in epithelial cells along the rat intestinal tract by immunofluorescence and immunoelectron microscopy. Both antibodies exclusively labeled the basolateral membrane of small intestine and proximal colon epithelial cells. However, in the distal colon, IEC 1/48, but not C 62.4, also labeled the brush border membrane. The cross-reacting beta-subunit-like antigen on the apical cell pole was tightly associated with isolated brush borders but was apparently devoid of (Na+ + K+)-ATPase activity. Subcellular fractionation of colonocytes in conjunction with limited proteolysis and surface radioiodination of intestinal segments suggested that the cross-reacting antigen in the brush border may be very similar to the beta subunit. The results support the notion that in the small intestine and proximal colon the enzyme subunits are exclusively targeted to the basolateral membrane while in the distal colon nonassembled beta subunit or a beta-subunit-like protein is also transported to the apical cell pole.

scholarly journals Murine endodermal cytokeratins Endo A and Endo B are localized in the same intermediate filament.

1986 ◽  
Vol 34 (6) ◽  
pp. 785-793 ◽  
Author(s):  
W E Howe ◽  
F G Klier ◽  
R G Oshima
Keyword(s):  
Immunoelectron Microscopy ◽  
Intermediate Filament ◽  
Microscopic Level ◽  
Cytoskeletal Proteins ◽  
Electron Microscopic Level ◽  
Electron Microscopic ◽  
Double Label ◽  
Secondary Antibodies ◽  
Endodermal Cells ◽  
20 Nm

The intracellular distribution of extra-embryonic endodermal, cytoskeletal proteins A (Endo A) and B (Endo B) was investigated by double-label immunofluorescent microscopy and double-label immunoelectron microscopy. In parietal endodermal cells, the immunofluorescent distribution of Endo B was always coincident with that of Endo A and could be distinguished from vimentin, particularly at the periphery of the cell. At the electron microscopic level, antibodies against both Endo A and Endo B recognized both bundles and individual intermediate filaments. Double-label immunoelectron microscopy was achieved by use of two sizes of colloidal gold particles (5 nm and 20 nm) that were stabilized with secondary antibodies. These results show that Endo A and B are found in the same intermediate filament and probably co-polymerize to form such structures.

Sign in / Sign up

Export Citation Format

Share Document