scholarly journals A COMPARATIVE STUDY OF THE ULTRASTRUCTURE OF MICROVILLI IN THE EPITHELIUM OF SMALL AND LARGE INTESTINE OF MICE

1967 ◽  
Vol 34 (2) ◽  
pp. 447-461 ◽  
Author(s):  
T. M. Mukherjee ◽  
A. Wynn Williams
Keyword(s):  
Small Intestine ◽  
Plasma Membrane ◽  
Fine Structure ◽  
Epithelial Cells ◽  
Surface Coat ◽  
Free Zone ◽  
Colonic Crypts ◽  
Mouse Intestine ◽  
Different Levels ◽  
Small And Large Intestine

A comparative analysis of the fine structure of the microvilli on jejunal and colonic epithelial cells of the mouse intestine has been made. The microvilli in these two locations demonstrate a remarkably similar fine structure with respect to the thickness of the plasma membrane, the extent of the filament-free zone, and the characteristics of the microfilaments situated within the microvillous core. Some of the core microfilaments appear to continue across the plasma membrane limiting the tip of the microvillus. The main difference between the microvilli of small intestine and colon is in the extent and organization of the surface coat. In the small intestine, in addition to the commonly observed thin surface "fuzz," occasional areas of the jejunal villus show a more conspicuous surface coat covering the tips of the microvilli. Evidence has been put forward which indicates that the surface coat is an integral part of the epithelial cells. In contrast to the jejunal epithelium, the colonic epithelium is endowed with a thicker surface coat. Variations in the organization of the surface coat at different levels of the colonic crypts have also been noted. The functional significance of these variations in the surface coat is discussed.

Changes in the fine structure of the apical plasma membrane of endometrial epithelial cells during implantation in the rat

1982 ◽  
Vol 55 (1) ◽  
pp. 1-12
Author(s):  
C.R. Murphy ◽  
J.G. Swift ◽  
T.M. Mukherjee ◽  
A.W. Rogers
Keyword(s):  
Plasma Membrane ◽  
Fine Structure ◽  
Epithelial Cells ◽  
Normal Pregnancy ◽  
Ovariectomized Rats ◽  
Apical Plasma Membrane ◽  
Embryonic Cells ◽  
Blastocyst Implantation ◽  
First Contact ◽  
Endometrial Epithelial Cells

In previous work we have shown that ovarian hormones, when injected into ovariectomized rats, alter the fine structure of the plasma membrane of endometrial epithelial cells. In this paper freeze-fractures have been used to study the apical plasma membrane of endometrial epithelial cells of rats during the period of blastocyst implantation of normal pregnancy. On day 1 of pregnancy there were 2354 +/− 114 intramembranous particles (IMPs) per micrometer2 of membrane. The particles were spherical and randomly distributed. On day 5 of pregnancy IMP density rose to 2899 +/− 289 per micrometer2 and some rod-shaped particles were also visible. By day 6 of pregnancy IMP density had risen to 4014 +/− 206 per micrometer2 and there were more rod-shaped IMPs than before. In addition, on day 6 IMPs were also present as rows of particles and some gap-junction-like arrays of particles were also seen. Our findings indicate that there are fine-structural alterations in the apical plasma membrane of endometrial epithelial cells, the site of first contact between maternal and embryonic cells, during the period of early pregnancy. The findings are discussed in the light of suggested mechanisms of blastocyst attachment to the uterine epithelium at implantation.

Surface Charge on Human Colinic Epithelial Cells as Shown by Ferritin Labelling

1972 ◽  
Vol 30 ◽  
pp. 266-267
Author(s):  
T. M. Mukherjee
Keyword(s):  
Plasma Membrane ◽  
Epithelial Cells ◽  
Brush Border ◽  
Negative Charge ◽  
Intestinal Epithelial Cells ◽  
Conclusive Evidence ◽  
Surface Coat ◽  
Intestinal Epithelial ◽  
Luminal Surface ◽  
Metabolic Activities

Recent observations suggest the glycoprotein surface coat of the intestinal epithelial cells to be involved in the metabolic activities of the absorptive cells. In fact such considerations led Crane to speculate and include the “glycocalyx” as an essential component of the “digestive absorptive surface”. In spite of such speculations no conclusive evidence in support of this contention has yet been obtained. One such speculation has been that the surface coat because of its high negative charge is responsible for the adsorption of materials prior to their terminal breakdown and absorption. To test this hypothesis a study was undertaken to reveal the charge distribution over the luminal surface, of the brush border plasma membrane, i.e. the region of the “glycocalyx”.

scholarly journals Relationships between intramembranous particles and surface coat carbohydrates in cells of a compact tissue

1983 ◽  
Vol 64 (1) ◽  
pp. 123-136
Author(s):  
C.R. Murphy ◽  
J.G. Swift
Keyword(s):  
Plasma Membrane ◽  
Epithelial Cells ◽  
Apical Plasma Membrane ◽  
Tissue Cell ◽  
Surface Coat ◽  
Intramembranous Particles ◽  
Structural Relationships ◽  
Surface Carbohydrates ◽  
In Cells

The structural relationships between intramembranous particles (IMPs) and surface carbohydrates have been studied in cells of a compact tissue—uterine epithelial cells—using an in vivo technique. This involves introducing small amounts of glycerol into the uterine lumen of anaesthetized rats. The treatment results in extensive aggregation of IMPs in the apical plasma membrane of the epithelial cells, but no change in the distribution of several surface carbohydrates could be detected. Our findings indicate that, in this case, the carbohydrates are not the surface expression of the IMPs, which are generally believed to represent integral membrane proteins. We suggest that the structural relationships between IMPs and surface carbohydrates in the plasma membrane of this compact tissue cell are more similar to those in membranes of free-floating nucleated cells than to those in the much-studied erythrocyte membrane.

scholarly journals Contraction of isolated brush borders from the intestinal epithelium.

1976 ◽  
Vol 70 (3) ◽  
pp. 541-554 ◽  
Author(s):  
R Rodewald ◽  
S B Newman ◽  
M J Karnovsky
Keyword(s):  
Small Intestine ◽  
Plasma Membrane ◽  
Epithelial Cells ◽  
Intestinal Epithelium ◽  
Intact Cell ◽  
Neonatal Rats ◽  
Heavy Meromyosin ◽  
Terminal Web ◽  
Brush Borders

Brush borders isolated from epithelial cells from the small intestine of neonatal rats are able to contract in the presence of ATP and Mg2+; Ca2+ is not required. Contraction is characterized by a pinching-in of the plasma membrane in the region of the zonula adherens and a subsequent rounding of the brush borders. No movement or consistent shortening of the microvilli is observed. The contraction appears to involve the 5- to 7-nm diameter microfilaments in the terminal web which associate with the zonula adherens. These filaments bind heavy meromyosin as do the actin core filaments of the microvilli. A model for contraction is presented in which, in the intact cell, terminal web filaments and core filaments interact to produce shortening of the microvilli.

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.

Electron probe x-ray microanalysis and electron microscopy of amino acid absorption and transport by the small intestine: inhibition by chemical poisons and correlation to the elemental composition of the epithelial cells

1986 ◽  
Vol 44 ◽  
pp. 134-135
Author(s):  
A. J. Tousimis
Keyword(s):  
Small Intestine ◽  
Amino Acid ◽  
Epithelial Cells ◽  
Elemental Composition ◽  
Isotope Labeling ◽  
Structural Components ◽  
X Ray ◽  
Human Small Intestine ◽  
Transport Studies

The elemental composition of amino acids is similar to that of the major structural components of the epithelial cells of the small intestine and other tissues. Therefore, their subcellular localization and concentration measurements are not possible by x-ray microanalysis. Radioactive isotope labeling: I131-tyrosine, Se75-methionine and S35-methionine have been successfully employed in numerous absorption and transport studies. The latter two have been utilized both in vitro and vivo, with similar results in the hamster and human small intestine. Non-radioactive Selenomethionine, since its absorption/transport behavior is assumed to be the same as that of Se75- methionine and S75-methionine could serve as a compound tracer for this amino acid.

The protease phenotype and crystalline nature of the granules of intraepithelial mast cells in Trichinella spiralis-infected mice

1995 ◽  
Vol 53 ◽  
pp. 818-819
Author(s):  
D.S. Friend ◽  
N. Ghildyal ◽  
M.F. Gurish ◽  
K.F. Austen ◽  
R.L. Stevens
Keyword(s):  
Small Intestine ◽  
Mast Cells ◽  
Epithelial Cells ◽  
Lamina Propria ◽  
Trichinella Spiralis ◽  
Intestinal Epithelial ◽  
Carboxypeptidase A ◽  
C3h Mice ◽  
Granule Morphology ◽  
Crystalline Nature

Trichinella spiralis induces a profound mastocytosis and eosinophilia in the small intestine of the infected mouse. Mouse mast cells (MC) store in their granules various combinations of at least five chymotryptic chymases [designated mouse MC protease (mMCP) 1 to 5], two tryptic proteases designated mMCP-6 and mMCP-7 and an exopeptidase, carboxypeptidase A (mMC-CPA). Using antipeptide, protease -specific antibodies to these MC granule proteases, immunohistochemistry was done to determine the distribution, number and protease phenotype of the MCs in the small intestine and spleen 10 to >60 days after Trichinella infection of BALB/c and C3H mice. TEM was performed to evaluate the granule morphology of the MCs between intestinal epithelial cells and in the lamina propria (mucosal MCs) and in the submucosa, muscle and serosa of the intestine (submucosal MCs).As noted in the table below, the number of submucosal MCs remained constant throughout the study. In contrast, on day 14, the number of MCs in the mucosa increased ~25 fold. Increased numbers of MCs were observed between epithelial cells in the mucosal crypts, in the lamina propria and to a lesser extent, between epithelial cells of the intestinal villi.

Membrane microdomains: lessons from microscopy

1995 ◽  
Vol 53 ◽  
pp. 776-777
Author(s):  
J.M. Robinson ◽  
J.M Oliver
Keyword(s):  
Spatial Distribution ◽  
Plasma Membrane ◽  
Epithelial Cells ◽  
Plasma Membranes ◽  
Cell Types ◽  
Imaging Modalities ◽  
Membrane Microdomains ◽  
Membrane Domains ◽  
Lateral Heterogeneity ◽  
Functional Importance

Specialized regions of plasma membranes displaying lateral heterogeneity are the focus of this Symposium. Specialized membrane domains are known for certain cell types such as differentiated epithelial cells where lateral heterogeneity in lipids and proteins exists between the apical and basolateral portions of the plasma membrane. Lateral heterogeneity and the presence of microdomains in membranes that are uniform in appearance have been more difficult to establish. Nonetheless a number of studies have provided evidence for membrane microdomains and indicated a functional importance for these structures.This symposium will focus on the use of various imaging modalities and related approaches to define membrane microdomains in a number of cell types. The importance of existing as well as emerging imaging technologies for use in the elucidation of membrane microdomains will be highlighted. The organization of membrane microdomains in terms of dimensions and spatial distribution is of considerable interest and will be addressed in this Symposium.

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