scholarly journals Ultrastructural localization of lectin receptors on the luminal and abluminal aspects of brain micro-blood vessels.

1986 ◽  
Vol 34 (2) ◽  
pp. 251-261 ◽  
Author(s):  
A W Vorbrodt ◽  
D H Dobrogowska ◽  
A S Lossinsky ◽  
H M Wisniewski
Keyword(s):  
Blood Vessels ◽  
Ricinus Communis ◽  
Helix Pomatia ◽  
Ultrastructural Localization ◽  
Con A ◽  
Gold Complexes ◽  
Entire Cross Section ◽  
Lectin Receptors ◽  
Helix Pomatia Agglutinin ◽  
Lowicryl K4m

Lectin- or glycoprotein-colloidal gold complexes were used for detection of specific monosaccharide residues in mouse brain micro-blood vessels (MBVs). The lectins tested recognize the following residues: beta-D-galactosyl (Ricinus communis agglutinin-120, RCA-1), alpha-N-acetylgalactosaminyl (Helix pomatia agglutinin, HPA), alpha-D-mannosyl and alpha-D-glucosyl (Concanavalin A, Con A), sialoglycoconjugates (Limax flavus agglutinin, LFA), N-acetylglucosaminyl and sialyl (wheat germ agglutinin, WGA), and alpha-L-fucosyl (Ulex europeus agglutinin, UEA-1). Use of these lectin-gold complexes and ultrathin sections of Lowicryl K4M-embedded tissue makes it possible to gain insights into localization of lectin receptors in the entire cross-section of MBV walls. Receptors for all lectins, except UEA-1, were found on both luminal and abluminal fronts of the endothelial cells (ECs). Differential labeling of luminal and abluminal fronts of ECs with some lectins (Con A, HPL) is considered to reflect the polarity of the endothelium. Some differences noted in the distribution of lectin receptors in the wall of representatives of three types of MBVs (capillaries, arterioles, and venules) are thought to be associated with different functions performed by the above-mentioned segments of the microvasculature in maintenance of the blood-brain barrier.

scholarly journals Immunogold study on lectin binding in the porcine zona pellucida and granulosa cells

10.4081/846 ◽  
2009 ◽  
Vol 47 (4) ◽  
pp. 353 ◽  
Author(s):  
F Parillo ◽  
C Dall’Aglio ◽  
A Verini Supplizi ◽  
P Ceccarelli ◽  
AM Gargiulo
Keyword(s):  
Sialic Acid ◽  
Horseradish Peroxidase ◽  
Granulosa Cells ◽  
Zona Pellucida ◽  
Lectin Binding ◽  
Protein A ◽  
Ultrastructural Localization ◽  
Binding Pattern ◽  
Con A ◽  
Lectin Receptors

An ultrastructural localization of lectin receptors on the zona pellucida (ZP) of porcine antral oocytes and on the granulosa cells was performed using a panel of horseradish peroxidase- labelled lectins in conjunction with antiperoxidase antibody and protein A-gold. In some cases, lectin incubation was preceded by sialidase digestion. WGA-, Con-A-, UEA-I-, RCA-I-, PNA- and SBA-reactive sites were distributed differently in the porcine ZP. Sialidase digestion increased the positivity obtained with RCA-I and it was necessary to promote PNA and SBA reactivity. These results indicated that the ZP contained N-acetylglucosamine, a-mannose, a- fucose, b-Gal-(1-4)GlcNAc, b-Gal- (1-3)GalNAc, b-GalNAc and sialic acid residues. We also observed the presence of vesicles in both the ooplasm and granulosa cells, showing a similar lectin binding pattern to that of the ZP, thus suggesting that the oocyte and granulosa cells are the site of synthesis of ZP glucidic determinants.

scholarly journals Ultrastructural localization of lectin-binding sites on the zonae pellucidae and plasma membranes of mammalian eggs.

1975 ◽  
Vol 66 (2) ◽  
pp. 263-274 ◽  
Author(s):  
G L Nicolson ◽  
R Yanagimachi ◽  
H Yanagimachi
Keyword(s):  
Binding Sites ◽  
Plasma Membranes ◽  
Ricinus Communis ◽  
Lectin Binding ◽  
Ultrastructural Localization ◽  
Con A ◽  
Plasma Membrane Receptor ◽  
Rat Eggs ◽  
Mammalian Eggs ◽  
Lectin Binding Sites

Receptors for Ricinus communis agglutinin I (RCAI), concanavalin A (Con A), and wheat germ agglutinin (WGA) were localized on the zonae pellucidae and plasma membranes of hamster, mouse, and rat eggs with ferritin-lectin conjugates. Intact eggs labeled with the ferritin conjugates showed dense concentrations of RCAI and WGA receptors in the outermost regions of their zonae pellucidae and sparse distributions of Con A receptors throughout the zonae. Ferritin-lectin labeling was specific, since inhibitory saccharides effectively blocked labeling. The asymmetric density of RCAI receptors across the zona was confirmed by ferritin-RCAI and fluorescein-RCAI labeling of mechanically isolated zonae pellucidae, indicating that the RCAI-binding sites are more densely distributed in the exterior zona regions. Plasma membranes of rodent eggs contained RCAI, WGA, and Con A receptors. These receptors were found to be more or less randomly distributed on surfaces of aldehyde-fixed eggs or on eggs labeled near 0 degrees C. However, eggs incubated at 25 degrees C showed aggregated WGA- and Con A-binding site distributions on their plasma membranes. This indicates that lectin-induced receptor redistribution occurs at this temperature. The possibility that plasma membrane receptor mobility is a requirement for sperm-egg fusion is discussed.

scholarly journals Lectin-binding sites on the plasma membranes of rabbit spermatozoa: Changes in surface receptors during epididymal maturation and after ejaculation

1977 ◽  
Vol 74 (3) ◽  
pp. 950-962 ◽  
Author(s):  
GL Nicolson ◽  
N Usui ◽  
R Yanagimachi ◽  
H Yanagimachi ◽  
Smith JR
Keyword(s):  
Binding Sites ◽  
Plasma Membranes ◽  
Ricinus Communis ◽  
Lectin Binding ◽  
Similar Degree ◽  
Con A ◽  
Lectin Receptors ◽  
Surface Receptors ◽  
Epididymal Spermatozoa ◽  
Lectin Binding Sites

Modifications in rabbit sperm plasma membranes during epididymal passage and after ejaculation were investigated by used of three lectins: concanavalin A (Con A); Ricinus communis I (RCA(I)); and wheat germ agglutinin (WGA). During sperm passage from caput to cauda epididymis, agglutination by WGA drastically decreased, and agglutination by RCA(I) slightly decreased, although agglutination by Con A remained approximately unchanged. After ejaculation, spermatozoa were agglutinated to a similar degree or slightly less by Con A, WGA, and RCA(I), compared to cauda epididymal spermatozoa. Ultrastructural examination of sperm lectin-binding sites with ferritin- lectin conjugates revealed differences in the densities of lectin receptors in various sperm regions, and changes in the same regions during epididymal passage and after ejaculation. Ferritin-RCA(I) showed abrupt changes in lectin site densities between acrosomal and postacrosomal regions of sperm heads. The relative amounts of ferritin-RCA(I) bound to heads of caput epididymal or ejaculated spermatozoa. Tail regions were labeled by ferritin RCA(I) almost equally on caput and cauda epididymal spermatozoa, but the middle-piece region of ejaculated spermatozoa was slightly more densely labeled than the principal-piece region, and these two regions on ejaculated spermatozoa were labeled less than on caput and cuada epididymal spermatozoa. Ferritin-WGA densely labeled the acrosomal region of caput epididymal spermatozoa, although labeling of cauda epidiymal spermatozoa was relatively sparse except in the apical area of the acrosomal region. Ejaculated spermatozoa bound only a few molecules of ferritin-WGA, even at the highest conjugate concentrations used. Caput epididymal, but not cauda epididymal or ejaculated spermatozoa, bound ferritin-WGA in the tail regions. Dramatic differences in labeling densities during epididymal passage and after ejaculation were not found with ferritin-Con A.

A scanning electron microscope study of lectin receptors on neuroblastoma cells

1978 ◽  
Vol 36 (2) ◽  
pp. 302-303
Author(s):  
P. Maher ◽  
R.S. Molday
Keyword(s):  
Ricinus Communis ◽  
Neuroblastoma Cells ◽  
Fluorescent Light ◽  
Con A ◽  
Polymeric Microspheres ◽  
Lectin Receptors ◽  
Scanning Electron Microscope Study ◽  
Visual Markers ◽  
Uniform Labeling ◽  
Scanning Electron

The organization and redistribution of concanavalin A (Con A), Ricinus communis agglutinin I (RCA I) and wheat germ agglutinin (WGA) receptors on mouse neuroblastoma cells was analyzed using lectins conjugated to fluorescent polymeric microspheres as visual markers for scanning electron microscopy (SEM) and fluorescent light microscopys. Results indicate that all three lectins are internalized by these cells but the patterns of redistribution for Con A differ from those of RCA I and WGA.Labeling of prefixed undifferentiated and differentiated neuroblastoma cells indicated that Con A, WGA and RCA I receptors were densely and uniformly distributed over the cell surface and neurites. Cells treated with lectin for 5-10 minutes at 37°C, washed free of excess reagent and maintained for up to 15 minutes in buffer exhibited uniform labeling patterns.

Localization of binding sites for concanavalin A, Ricinus communis I and Helix pomatia lectin in the Golgi apparatus of rat small intestinal absorptive cells.

1985 ◽  
Vol 33 (9) ◽  
pp. 905-914 ◽  
Author(s):  
M Pavelka ◽  
A Ellinger
Keyword(s):  
Golgi Apparatus ◽  
Binding Sites ◽  
Ricinus Communis ◽  
Helix Pomatia ◽  
Con A ◽  
Absorptive Cells ◽  
Intermediate Compartment ◽  
Small Intestinal ◽  
The One ◽  
Helix Pomatia Lectin

Binding sites for concanvalin A (Con A), Ricinus communis I agglutinin (RCA I), and Helix pomatia lectin (HPA) were localized in the Golgi apparatus of rat small intestinal absorptive cells. A preembedment technique, a modification of the one originally used by Bernhard and Avrameas (Exp Cell Res 64:232, 1971), was employed, with horse-radish peroxidase being used for cytochemical visualization. Incubations were performed on 10 microns thick cryosections of duodenal segments that were fixed in a mixture of 4% formaldehyde and 0.5% glutaraldehyde; fixation was preceded by a 2-min rinse in 0.1 M sodium cacodylate and followed by storage in the same buffer for up to 7 days. Incubation with Con A, which binds preferably to alpha-D-mannose and alpha-D-glucose residues, caused intense reaction of the dilated cisternae of the cis Golgi side; staining was variable in intermediate and trans cisternae. RCA I, recognizing beta-D-galactose residues, could only be demonstrated in intermediate cisternae. Reaction for HPA, which indicates alpha-N-acetyl-D-galactosamine residues, stained intensely 1 to 2 cisternae of the cis Golgi side, as well as being localized in the peripheral regions of the cisternae of the intermediate compartment of the stacks. Deposits of reaction product covered the luminal surface of the cisternal membranes, but usually left the lumen itself, as well as lipid particles, devoid of reaction. The differences in Con A, RCA I, and HPA reactivity between cis, intermediate, and trans cisternae suggest compositional and structural differences of the carbohydrates in the respective compartments; they may reflect conversion processes that are known to occur in the oligosaccharide side chains of glycoconjugates at the Golgi complex level.

scholarly journals Distinct cytoskeletal domains revealed in sperm cells.

1984 ◽  
Vol 99 (3) ◽  
pp. 1083-1091 ◽  
Author(s):  
I Virtanen ◽  
R A Badley ◽  
R Paasivuo ◽  
V P Lehto
Keyword(s):  
Ricinus Communis ◽  
Surface Membrane ◽  
Helix Pomatia ◽  
Cytoskeletal Proteins ◽  
Sperm Cells ◽  
Positive Staining ◽  
Specific Staining ◽  
Cytoskeletal Organization ◽  
Helix Pomatia Agglutinin ◽  
Principal Piece

Antibodies against different cytoskeletal proteins were used to study the cytoskeletal organization of human spermatozoa. A positive staining with actin antibodies was seen in both the acrosomal cap region and the principal piece region of the tail. However, no staining was obtained with nitrobenzoxadiazol-phallacidin, suggesting that most of the actin was in the nonpolymerized form. Most of the myosin immunoreactivity was confirmed to a narrow band in the neck region of spermatozoa. Tubulin was located to the entire tail, whereas vimentin was only seen in a discrete band-like structure encircling the sperm head, apparently coinciding with the equatorial segment region. Surface staining of the spermatozoa with fluorochrome-coupled Helix pomatia agglutinin revealed a similar band-like structure that co-distributed with the vimentin-specific staining. Instead, other lectin conjugates used labeled either the acrosomal cap region (peanut and soybean agglutinins), both the acrosomal cap and the postacrosomal region of the head (concanavalin A), or the whole sperm cell surface membrane (wheat germ and lens culinaris agglutinins and ricinus communis agglutinin l). In lectin blotting experiments, the Helix pomatia agglutinin-binding was assigned to a 80,000-mol-wt polypeptide which, together with vimentin, also resisted treatment with Triton X-100. Only the acrosomal cap and the principal piece of the tail were decorated with rabbit and hydridoma antibodies against an immunoanalogue of erythrocyte alpha-spectrin (p230). p230 appeared to be the major calmodulin-binding polypeptide in spermatozoa, as shown by a direct overlay assay of electrophoretic blots of spermatozoa with 125I-calmodulin. The results indicate that spermatozoa have a highly specialized cytoskeletal organization and that the distribution of actin, spectrin, and vimentin can be correlated with distinct surface specializations of the sperm cells. This suggest that cytoskeleton may regulate the maintenance of these surface assemblies and, hence, affect the spermatozoan function.

Effect on glutaraldehyde fixation on lectin-mediated agglutination of mouse leukaemia cells

1976 ◽  
Vol 21 (3) ◽  
pp. 579-594
Author(s):  
W.J. Van Blitterswijk ◽  
E.F. Walborg ◽  
C.A. Feltkamp ◽  
H.A. Hilkmann ◽  
P. Emmelot
Keyword(s):  
Ricinus Communis ◽  
Single Cells ◽  
Cell Aggregation ◽  
Cell Counting ◽  
Cell Aggregates ◽  
Glutaraldehyde Fixation ◽  
Shear Forces ◽  
Con A ◽  
Lectin Receptors ◽  
Free Surfaces

The effect of glutaraldehyde fixation on lectin-mediated agglutination of murine leukaemia (GRSL) cells was investigated using 2 assay methods which differed in the shear forces to which the agglutinated cells were subjected. First, lectin and cells were allowed to interact under conditions in which shear forces were minimized and the degree of agglutination was evaluated microscopically by the appearance and size of the cell aggregates. This assay demonstrated that concanavalin A (con A)-, wheat germ agglutinin (WGA)- or Ricinus communis agglutinin I (RCAI)-mediated cytoagglutination was unaffected (WGA and RCAI) or somewhat enhanced (con A) by prior fixation of the cells with glutaraldehyde. Secondly, an electronic particle counter was used to measure the disappearance of single cells and concomitant appearance of cell aggregates as a function of the lectin concentration. In this assay, in which the aggregated cells are subjected to significant shear forces during dilution and cell counting, agglutination of GRSL cells by each of the 3 lectins was drastically inhibited by prior fixation of the cells with glutaraldehyde. This assay also demonstrated enhanced nonlectin-induced cell aggregation after fixation. In both cytoagglutination assays about the same lectin concentration was required for threshold agglutination of unfixed cells. Comparatively, the results of the 2 cytoagglutination assays indicate that a fraction of the lectin-mediated bonds between unfixed cells is shear resistant and that fixation of the cells either weakens these bonds or inhibits their formation. Morphologically, cells prefixed with glutaraldehyde were sperical at all lectin concentrations, with a continuous dense distribution of cell surface-bound con A, labelled directly with haemocyanin or indirectly using the peroxidase-diaminobenzidine reaction. Unfixed cells showed angular and toadstool-shaped deformations, especially at the highest lectin concentrations, the agglutinating surfaces being flattened against each other over extended areas. The distribution of con A label was continuous and dense between the apposed surfaces and discontinuous on free surfaces. In the presence of con A the free surfaces of prefixed cells exhibited more microvilli than the surfaces of non-prefixed cells. These results favour the view that fixation prevents the formation of shear-resistant, lectin-mediated bonds between cells, not by restricting the lateral mobility of lectin receptors, but by impairing the apposition of rigid cell surfaces.

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