Lectin histochemical study on the infraorbital gland of the Japanese serow (Capricornis crispus)

Histology and lectin histochemistry were performed in the infraorbital gland of the Japanese serow. The gland is composed of glandular tissues and a pouch filled with the secretion. The tissues consist of an inner layer of sebaceous glands and an outer layer of apocrine glands. The male sebaceous layer is made up of the ordinary type, whereas the female's layer consists of the ordinary and modified types. In the apocrine gland stained with Arachis hypogaea (PNA), nine different patterns of glandular tubules were distinguished on the basis of staining of the cytoplasm, the Golgi area of secretory cells and secretion. Secretory modes of apocrine secretion and exocytosis were included in these stainings. Myoepithelial cells stained constantly with Glycine max (SBA) except when only the Golgi area of secretory cells was positive. The modified sebaceous gland was stained with PNA, SBA, Ricinus communis I (RCA), Triticum vulgaris (WGA), Canavalia ensiformis (Con A) and Ulex europaeus I (UEA), while the ordinary type was positive in PNA, RCA, SBA, WGA and Con A. The secretion in the pouch was stained with PNA, RCA, SBA, Dolichos biflorus (DBA), WGA and Con A. These findings suggest that the modified sebaceous gland contains large amounts of glycoconjugates and the apocrine gland shows a cyclic secretory process of apocrine secretion and exocytosis.     

Changes in lectin-binding pattern in the digestive tract of Xenopus laevis during metamorphosis. I. Gastric region.

The distribution of structural and secretory glycoconjugates in the gastric region of metamorphosing Xenopus laevis was studied by the avidin-biotin-peroxidase (ABC) histochemical staining method using seven lectins (concanavalin A, Con A; Dolichos biflorus agglutinin, DBA; peanut agglutinin, PNA; Ricinus communis agglutinin I, RCA-I; soybean agglutinin, SBA; Ulex europeus agglutinin I, UEA-I; and wheat germ agglutinin, WGA). Throughout the larval period to stage 60, the epithelium consisting of surface cells and gland cells was stained in various patterns with all lectins examined, whereas the thin layer of connective tissue was positive only for RCA-I. At the beginning of metamorphic climax, the connective tissue became stained with Con A, SBA, and WGA, and its staining pattern varied with different lectins. The region just beneath the surface cells was strongly stained only with RCA-I. With the progression of development, both the epithelium and the connective tissue gradually changed their staining patterns. The surface cells, the gland cells, and the connective tissue conspicuously changed their staining patterns, respectively, for Con A and WGA; for Con A, PNA, RCA-I, SBA, and WGA; and for Con A, RCA-I, and WGA. At the completion of metamorphosis (stage 66), mucous neck cells became clearly identifiable in the epithelium, and their cytoplasm was strongly stained with DBA, PNA, RCA-I, and SBA. These results indicate that lectin histochemistry can provide good criteria for distinguishing among three epithelial cell types, namely, surface cells, gland cells, and mucous neck cells, and between adult and larval cells of each type.     

Eosinophilic globule cells in mouse MFH-like sarcomas: lectin histochemistry.

Lectin binding patterns in ten mouse malignant fibrous histiocytoma (MFH)-like sarcomas containing eosinophilic globule (EG) cells and in granular metrial gland (GMG) cells of mouse placenta were stained with nine lectins (Con A, LCA, WGA, DBA, SBA, e-PHA, PNA, RCA-I and UEA-I) by an avidin-biotin-peroxidase-complex method. EG cells stained strongly with DBA, SBA and PNA which are specific for N-acetyl-D-galactosamine and/or D-galactose. DBA and SBA bound throughout the cytoplasm including the globules; PNA reacted preferentially at the cell surface. There was no evidence that these three lectins were reactive for immature EG cells. WGA, RCA-I and e-PHA also gave a slightly to moderately positive reaction to globules of EG cells. The results indicate that the globules contain abundant O-linked sequences of sugars, but also a few N-linked residues. MFH tumor cells showed a variable degree of binding with Con A, RCA-I, and WGA, but did not react with DBA, SBA and PNA. On the other hand, GMG cells exhibited specific affinities for DBA, SBA and PNA with staining patterns similar to those of EG cells. These findings suggest that EG and GMG cells may be of the same cellular lineage.     

Lectin binding to newt epidermis: fluorescent localization and effects on motility

The ability of seven lectins to bind to newt epidermal cells and influence their motility was examined. Of the seven fluoresceinated lectins applied to frozen sections containing intact newt skin and migrating epidermis (wound epithelium), only Con A (concanavalin A), WGA (wheat germ agglutinin), and PNA (peanut agglutinin) produced detectable epidermal fluorescence. Con A and WGA each heavily labeled all layers of intact epidermis, but PNA bound only to the more superficial layers. In contrast to a single population of labeled cells in migrating epidermal sheets after treatment with Con A, there were both labeled and unlabeled cells after exposure to either WGA or PNA. The wound bed was labeled by both Con A and WGA, but not by PNA. DBA (Dolichos bifloris agglutinin), RCA I (Ricinus communis agglutinin), and UEA (Ulex europaeus agglutinin), did not produce significant fluorescence with either migrating or intact epidermis. In general, inhibitory effects on epidermal motility correlated with the binding studies. Thus, Con A, WGA, and PNA, the lectins which clearly bound to the epidermis, all produced a concentration-dependent depression in the rate of epidermal wound closure. RCA was somewhat paradoxical in that it was moderately inhibitory despite showing essentially no binding. The effects of SBA and UEA were equivocal. DBA had no effect. These results indicate that the inhibition of motility produced by Con A that we have described previously is not peculiar to this mannose-binding lectin, but is shared by at least one lectin with an affinity for D-GlcNAc (WGA), and one with an affinity for B-D-Gal(1-3)-D-GalNAc (PNA).(ABSTRACT TRUNCATED AT 250 WORDS)     

Heterogeneity of cell population of lymphoma NK/Ly and leukemia L-1210 according to carbohydrate structure of cell surface: immunocytochemical analysis of lectin binding

The heterogeneity of tumor cell populations according to binding of lectins from lentil (LcL), wheat germs (WGA), peanut (PNA) and concanavalin A was investigated on a model of murine Nemeth-Kellner lymphoma (NK/Ly) and leukemia L-1210. Bound lectins were detected by indirect immunochemical method using home obtained polyclonal antilectin antibodies and immunogold silver staining (IGSS) technique. Significant differences in binding of Con A were revealed between NK/Ly (67% Con A+) and L-1210 (7.2% Con A+) cells, while the differences in binding of other lectins with both types of tumor cells were not significant. A relatively high percentage of PNA+ cells was registered that can indicate a high degree of desialization of membrane glycoproteins.     

Trypanosoma rhodesiense bloodstream trypomastigote and culture procyclic cell surface carbohydrates

Bloodstream trypomastigote and culture procyclic (insect midgut) forms of a cloned T. rhodesiense variant (WRAT at 1) were tested for agglutination with the lectins concanavalin A (Con A), phytohemagglutinin P (PP), soybean agglutinin (SBA), fucose binding protein (FBP), wheat germ agglutinin (WGA), and castor bean lectin (RCA). Fluorescence-microscopic localization of lectin binding to both formalin-fixed trypomastigotes and red cells was determined with fluorescein isothiocyanate (FITC)-conjugated Con A, SBA, FBP, WGA, RCA, PNA (peanut agglutinin), DBA (Dolichos bifloris), and UEA (Ulex europaeus) lectins. Electron microscopic localization of lectin binding sites on bloodstream trypomastigotes was accomplished by the Con A-horseradish peroxidase-diamino-benzidine (HRP-DAB) technique, and by a Con A-biotin/avidin-ferritin method. Trypomastigotes, isolated by centrifugation or filtration through DEAE-cellulose or thawed after cryopreservation, were agglutinated by the lectins Con A and PP with agglutination strength scored as Con A greater than PP. No agglutination was observed in control preparations or with the lectins WGA, FBA or SBA. Red cells were agglutinated by all the lectins tested. Formalin-fixed bloodstream trypomastigotes bound FITC-Con A and FITC-RCA but not FITC-WAG, -SBA, -PNA, -UEA or -DBA lectins. All FITC-labeled lectins bound to red cells. Con A receptors, visualized by Con A-HRP-DAB and Con A-biotin/avidin-ferritin techniques, were distributed uniformly on T. rhodesiense bloodstream forms. No lectin receptors were visualized on control preparations. Culture procyclics lacked a cell surface coat and were agglutinated by Con A and WGA but not RCA, SBA, PP and FBP. Procyclics were not agglutinated by lectins in the presence of competing sugar at 0.25 M.(ABSTRACT TRUNCATED AT 250 WORDS)     

Changes in lectin-binding pattern in the digestive tract of Xenopus laevis during metamorphosis. II. Small intestine.

The binding of seven lectins (concanavalin A, Con A; Dolichos biflorus agglutinin, DBA; peanut agglutinin, PNA; Ricinus communis agglutinin I, RCA-I; soybean agglutinin, SBA; Ulex europeus agglutinin, UEA-I; and wheat germ agglutinin, WGA) to the small intestine in metamorphosing Xenopus laevis was studied by the avidin-biotin-peroxidase (ABC) method. The staining pattern of the epithelium with all lectins except for UEA-I and Con A changed gradually during metamorphic climax; the main component of the epithelium, absorptive cells, gradually became positive for DBA, PNA, and SBA and the scattered goblet cells for RCA-I and WGA. On the other hand, the change of the staining pattern in the connective tissue occurred only for Con A, RCA-I, and WGA, and this change took place rapidly at the beginning of climax (stage 60). Increased staining for Con A and WGA at stage 60 was observed only in a group of connective tissue cells close to the epithelium and in the basement membrane. As metamorphosis progressed, this localization of the staining intensity became less clear. At the completion of metamorphosis (stage 66), the absorptive cells were stained with all lectins except for UEA-I, whereas the goblet cells stained only with RCA-I and WGA. These results indicate that lectin histochemistry can distinguish between larval and adult cells of both two epithelial types (absorptive and goblet cells). The technique may also identify a group of connective tissue cells, close to the epithelium, that possibly induce the metamorphic epithelial changes.     

Different binding to squamous and columnar epithelium of the uterine cervix as a marker of epithelial differentiation

Biotinylated lectins were used to investigate the expression of carbohydrate residues on columnar and squamous epithelium of the uterine cervix. Con A, WGA, RCA I, PNA, UEA I, DBA and SBA were used. In the native exocervical and in metaplastic squamous epithelium of the transformation zone, one group of lectins (Con A, WGA, RCA I and PNA) stained the cell periphery of all epithelial layers. A second group (UEA I, DBA and SBA) colored the cell periphery of the suprabasal cells. The basal layer was always negative. All lectins labeled the apical border and occasionally the cytoplasm of the endocervical columnar epithelium. Lectin-binding of metaplastic and native squamous epithelium could possibly be used as a marker of epithelial differentiation in normal and abnormal conditions.     

Lectin binding to rat spermatogenic cells: Effects of different fixation methods and proteolytic enzyme treatment

Summary The binding of a panel of eight different fluorescein-conjugated lectins to rat spermatogenic cells was investigated. Particular attention was paid to the effects of different fixation methods and proteolytic enzyme digestion on the staining pattern.Concanavalin A (Con A), wheatgerm agglutinin (WGA), succinylated WGA (s-WGA) and agglutinin from gorse (UEA I) stained the cytoplasm of most germ cells as well as the spermatid acrosome. In contrast, peanut agglutinin (PNA), castor bean agglutinin (RCAI) and soy bean agglutinin (SBA) mainly stained the acrosome. The staining pattern varied depending on the fixation method used. PNA was particularly sensitive to formalin fixation, while SBA, DBA and UEA I showed decreased binding and Con A, WGA, s-WGA and RCA I were insensitive to this type of fixation. Pepsin treatment of the sections before lectin staining caused marked changes in the staining pattern; staining with PNA in formalin-fixed tissue sections was particularly improved but there was also enhanced staining with SBA and horse gram agglutinin (DBA). On the other hand, in Bouin- and particularly in acetone-fixed tissue sections, pepsin treatment decreased the staining with several of the lectins, for example WGA and UEA I.     

Effects of plant lectins on the adhesive properties of baby hamster kidney cells

We studied the effects of different lectins on the adhesive properties of baby hamster kidney (BHK) cells. The purpose of these studies was to learn more about the cell surface receptors involved in cell adhesion. Three adhesive phenomena were analyzed: 1) the adhesion of BHK cells to lectin-coated substrata; 2) the effects of lectins on the adhesion of cells to substrata coated by plasma fibronectin (pFN); and 3) the effects of lectins on the binding of pFN-coated beads to cells. Initial experiments with fluorescein-conjugated lectins indicated that concanavalin A (Con A), ricinus communis agglutinin I (RCA I), and wheat germ agglutinin (WGA) bound to BHK cells but peanut agglutinin (PNA), soybean agglutinin (SBA), and ulex europaeus agglutinin I (UEA I) dod not bind. All three of the lectins which bound to the cells promoted cell spreading on lectin substrata, and the morphology of the spread cells was similar to that observed with cells spread on pFN substrata. Protease treatment of the cells, however, was found to inhibit cell spreading on pFN substrata or WGA substrata more than on Con A substrata or RCA I substrata. In the experiment of cells with Con A or WGA inhibited cell spreading on pFN substrata, but RCA I treatment had no effect. Finally, treatment of cells with WGA inhibited binding to cells of pFN beads, but neither Con A nor RCA I affected this interaction. These results indicate that the lectins modify cellular adhesion in different ways, probably by interacting with different surface receptors. The possibility that the pFN receptor is a WGA receptor is discussed.     

The lectin binding pattern of normal and pathologically altered synovial tissue

Light-microscopical lectin-binding studies were carried out in healthy and pathologically altered synovial tissue (osteoarthrosis, rheumatoid arthritis (RA)). Seven lectins were studied: Con A, DBA, PNA, RCA, SBA, UEA-I, and WGA. Con A and WGA mark all lining cells and the majority of subintimal synovial cells. RCA and SBA stain only a portion of lining cells, regardless of the basic pathology. The lectin PNA reacts only with RA and arthrotic material, and is thus suitable for the diagnosis of inflammatory changes in synovial tissue. UEA-1 is a consistent marker for capillary endothelium and large vessels.     

Trypanosoma rhodesiense Bloodstream Trypomastigote and Culture Procyclic Cell Surface Carbohydrates1, 2, 3

Bloodstream trypomastigote and culture procyclic (insect midgut) forms of a cloned T. rhodesiense variant (WRATat 1) were tested for agglutination with the lectins concanavalin A (Con A), phytohemagglutinin P (PP), soybean agglutinin (SBA), fucose binding protein (FBP), wheat germ agglutinin (WGA), and castor bean lectin (RCA). Fluorescence-microscopic localization of lectin binding to both formalin-fixed trypomastigotes and red cells was determined with fluorescein isothiocyanate (FITC)-conjugated Con A, SBA, FBP, WGA, RCA, PNA (peanut agglutinin), DBA (Dolichos bifloris), and UEA (Ulex europaeus) lectins. Electron microscopic localization of lectin binding sites on bloodstream trypomastigotes was accomplished by the Con A-horseradish peroxidase-diaminobenzidine (HRP-DAB) technique, and by a Con A-biotin/avidin-ferritin method. Trypomastigotes, isolated by centrifugation or filtration through DEAE-cellulose or thawed after cryopreservation, were agglutinated by the lectins Con A and PP with agglutination strength scored as Con A < PP. No agglutination was observed in control preparations or with the lectins WGA, FBA or SBA. Red cells were agglutinated by all the lectins tested. Formalin-fixed bloodstream trypomastigotes bound FITC-Con A and FITC-RCA but not FITC-WGA, -SBA, -PNA, -UEA or -DBA lectins. All FITC-labeled lectins bound to red cells. Con A receptors, visualized by Con A-HRP-DAB and Con A-biotin/avidin-ferritin techniques, were distributed uniformly on T. rhodesiense bloodstream forms. No lectin receptors were visualized on control preparations. Culture procyclics lacked a cell surface coat and were agglutinated by Con A and WGA but not RCA, SBA, PP and FBP. Procyclics were not agglutinated by lectins in the presence of competing sugar at 0.25 M. The expression of lectin binding cell surface saccharides of T. rhodesiense WRATat 1 is related to the parasite stage. Sugars resembling α-D-mannose are on the surface of bloodstream trypomastigotes and culture procyclics; n-acetyl-D-galactosamine and D-galactose residues are on bloodstream forms; and n-acetyl-D-glucosamine-like sugars are on procyclic stages.     

Binding of fluorescein isothiocyanate conjugated lectins to rat spermatogenic cells in tissue sections. Enhancement of lectin fluorescence obtained by fixation in Bouin's fluid

The testes from three months old Sprague-Dawley rats were fixed in Bouin's fluid or neutral buffered 10% formalin, embedded in paraffin, sectioned and after deparaffination stained with the following fluorescein isothiocyanate coupled lectins: PNA, WGA, Con A, RCA, SBA, DBA and UEA. The results show that there are considerable differences in the staining pattern of various spermatogenic cells between different lectins. The fixation in Bouin's fluid enhanced the staining of all the lectins compared to formalin fixation in which only a weak staining could be seen in the acrosomes of spermatids after WGA or PNA staining. PNA and WGA stained specifically the acrosome of the developing spermatids, which was seen from the beginning of the acrosome formation and lasted up to late spermiogenesis. However, the staining with PNA decreased in the late spermatids whereas the intensity of the staining remained unchanged with WGA. Con A did not stain the acrosome but stained unspecifically the cytoplasm of all spermatogenic cells. RCA stained faintly the acrosome throughout the spermatid differentiation. DBA and UEA stained specifically the chromosomes of B spermatogonia. DBA also faintly stained the cell membranes of early spermatids. SBA did not show any specific staining of the spermatogenic cells. Based on this it is suggested that the carbohydrates and glycoproteins which are known to be present in the acrosome are formed already in the beginning of the acrosome formation. The decrease in the PNA staining in late spermatids possibly reflects the fact that the receptor molecules are not synthesized in late spermatids but are formed in earlier developmental stages and are thereafter preserved in the acrosome.(ABSTRACT TRUNCATED AT 250 WORDS)     

Characterization of glycoconjugates of human gastrointestinal mucosa by lectins. I. Histochemical distribution of lectin binding sites in normal alimentary tract as well as in benign and malignant gastric neoplasms

Labeled lectins with binding specificity to the hexose components of mucus glycoproteins (HPA, RCA I, PNA, Con A, WGA, and UEA I) were used to demonstrate structural differences in the glycoprotein composition of various cell types of the normal, benign and malignant gastrointestinal mucosa. While in the RCA I, UEA I, and WGA binding of normal mucus secreting cell types only quantitative differences were observed, the mucus in the surface epithelial cells of gastric mucosa and in the colonic goblet cells was characterized by the absence of PNA, Con A, and PNA, HPA binding sites, respectively. These lectins, however, showed a strong binding to the supranuclear, Golgi-region in the undifferentiated or activated forms of these cells. Even the staining intensity of the luminal membrane surfaces of the non mucinous parietal and chief cells was often stronger by PNA, HPA, and RCA I lectins than that of the mucus secretions in the highly differentiated mucus cells. These results indicate the existence of either heterogeneous glycoprotein components or mucus molecules with variations in the degree of glycosylation of their oligosaccharide chains in the different cells. The latter seems more likely since in benign and malignant alterations lectin binding sites appear in great density, which were found to be characteristic of the undifferentiated mucus cells or for the non mucinous cells of the normal gastric mucosa. Similarly in some gastric cancers which do not stain with the periodic acid-Schiff reaction at all, large amount of free or neuraminic acid substituted PNA binding sites can be detected.     

Distribution of lectin receptors in postimplantation mouse embryos at 6-8 days gestation

We have examined the pattern of binding of eleven lectins--BSL-II, WGA, LPA, Con A, DBA, SBA, LTA, UEA-I, MPA, PNA, and RCA-I, with specificity for a range of saccharides, to postimplantation mouse embryos from 6 to 8 days of gestation. The lectins were used to stain sections of ethanol-fixed paraffin-embedded and formaldehyde-fixed gelatin-embedded embryonic material. Our observations reveal a complex pattern of lectin binding to both cell surfaces and cytoplasm. Many of the lectins bind particularly to the outer surface of visceral endoderm (e.g., DBA, WGA, SBA, and RCA-I) and to the surface of the proamniotic cavity (e.g., RCA-I, PNA, and WGA). In the newly formed mesenchyme of primitive-streak-stage embryos, galactose and N-Ac-neuraminic acid are present but lectins with specificity for other sugars either did not bind to the cells or bound only in small amounts.     

Lectin histochemistry of mammalian Brunner's glands

Lectin histochemical study was performed on twenty-eight specimens of formalin-fixed paraffin embedded tissues of proximal duodenum from human, cat, dog and Rhesus (macaque) monkey to demonstrate the pattern of carbohydrate residues in submucosal glands of Brunner as compared to that of the duodenal absorptive and goblet cells. Ten different biotinylated lectins were used as probes, and avidin-biotin-peroxidase (ABC) or avidin-gold-silver (AGS) complexes were used as "visualants". Brunner's gland cells of the four species studied exhibited a similar lectin-binding pattern which differ from other duodenal cells. The epithelium of Brunner's gland stained intensely with Ricinus communis agglutinin-I (RCA-I), succinylated-WGA (S-WGA) and wheat-germ agglutinin (WGA), moderately with Bandeirea simplicifolia agglutinin-I (BS-I), Concanavalia ensiformis agglutinin (Con A) peanut agglutinin (PNA) and Ulex europaeus agglutinin-I (UEA-I) and occasionally with Dolichos biflorus agglutinin (DBA), Lens culinaris agglutinin (LCA) and soybean agglutinin (SBA). Desialylation with neuraminidase resulted in only a slight elevation in binding intensities of PNA, DBA and SBA, indicating that glycoconjugates of the Brunner's gland cells are rich in asialo-oligosaccharides, which differs from duodenal epithelial cells. In addition, these histochemical reagents were useful in localizing Brunner's gland elements in the duodenal mucosa.     

Lectin histochemistry of the hyaline layer in the asteroid,pisaster ochraceus

Six different lectins were used to study the carbohydrate nature of the hyaline layer (HL), the external extracellular matrix of the starfish embryo. Thin sections of embryos fixed in the late gastrula stage were incubated with five fluoresceinated lectins: Con A, WGA, RCA, UEA-I, and SBA. All but UEA-I labelled the HL, suggesting that the following sugars are present: mannose and/or glucose, glcNAc and/or Neu5Ac, galactose, and galNAc. The different lectins produced variable degrees of labelling, with WGA, RCA, and SBA producing more intense labelling than Con A. Binding of lectins by the HL was studied at the ultrastructural level by exposing ultrathin sections to the following lectin-gold conjugates: Con A, WGA, PNA, SBA, and LFA. Lectin binding was observed over the various regions of the HL, recognized by Crawford and Abed (J. Morphol. 176:235–246, '86), i.e., the intervillus layer, the supporting layer and the coarse outer meshwork. Local differences in labelling patterns were observed among the various lectins, with SBA labelling all regions intensely, WGA and PNA labelling the supporting layer predominantly, and Con A labelling the HL only lightly. No labelling was observed with LFA. These lectin-labelling patterns in the HL demonstrate the presence of different glycoconjugates in different regions of the HL, suggesting that the layers differ biochemically. The existence of biochemical differences strengthens the idea that each layer may have different functions in the developing starfish embryo.     

Postnatal development of lectin binding sites in the rat ventral prostate

Summary Five Fluorescein-isothiocyanate (FITC)-labelled lectins were used to study the postnatal development of carbohydrate constituents in the rat ventral prostate: Concanavalin A (Con A), wheat germ agglutinin (WGA), peanut agglutinin (PNA),Dolichos biflorus agglutinin (DBA) andRicinus communis agglutinin I (RCA-I) With all the lectins, tested, except RCA-I, specific binding sites could be shown for every stage of differentiation in the glandular epithelium. Binding sites for Con A, WGA, PNA and DBA were found from day 10 to 13 post partum onwards. Each lectin showed a characteristic localization. Binding sites for the lectins used changed to different extents during the following two weeks. After the 24th day post partum no further changes in the lectin binding pattern could be found. The development of the lectin binding properties showed that the changes in carbohydrate-containing constituents of the prostate correlate with the beginning of prostatic secretion and to prostatic epithelial differentiation. In the periacinar stroma the development of the lectin binding pattern was similar to that in the glandular epithelium. The changes of stromal binding sites for Con A and WGA during epithelial differentiation may reflect the changes of epithelial-stromal interactions in the prostate.     

Effect of thyroid hormones on the histotopography of lectin receptors in the rat salivary gland

Using lectin-peroxidase technique, the influence of hypo- and hyperthyroidism on histotopography of glycoconjugates has been investigated in rat submandibular gland. The following lectins were used: peanut agglutinin (PNA), wheat germ agglutinin (WGA), Laburnum anagyroides lectin (LAL) and concanavalin A (con A). It has been demonstrated that hyperthyroidism is accompanied by the loss of con A, WGA and LAL receptor sites. Hypothyrodism enhanced con A binding to granular duct cells with a parallel reduction in WGA and LAL binding to these or other duct cells. Hypothyroidism as well as hyperthyroidism markedly enhanced PNA binding to duct epitheliocytes with redistribution of these lectin binding sites from the luminal surface of salivary ducts into the cytoplasm of duct cells. Possible interpretations of the observed phenomena are discussed.     

Binding of fluorescein isothiocyanate conjugated lectins to rat spermatogenic cells in tissue sections

Summary The testes from three months old Spague-Dawley rats were fixed in Bouin's fluid or neutral buffered 10% formalin, embedded in paraffin, sectioned and after deparaffination stained with the following fluorescein isothiocyanate coupled lectins: PNA, WGA, Con A, RCA, SBA, DBA and UEA. The results show that there are considerable differences in the staining pattern of various spermatogenic cells between different lectins. The fixation in Bouin's fluid enhanced the staining of all the lectins compared to formalin fixation in which only a weak staining could be seen in the acrosomes of spermatids after WGA or PNA staining. PNA and WGA stained specifically the acrosome of the developing spermatids, which was seen from the beginning of the acrosome formation and lasted up to late spermiogenesis. However, the staining with PNA decreased in the late spermatids whereas the intensity of the staining remained unchanged with WGA. Con A did not stain the acrosome but stained unspecifically the cytoplasm of all spermatogenic cells. RCA stained faintly the acrosome throughout the spermatid differentiation. DBA and UEA stained specifically the chromosomes of B spermatogonia. DBA also faintly stained the cell membranes of early spermatids. SBA did not show any specific staining of the spermatogenic cells. Based on this it is suggested that the carbohydrates and glycoproteins which are known to be present in the acrosome are formed already in the beginning of the acrosome formation. The decrease in the PNA staining in late spermatids possibly reflects the fact that the receptor molecules are not synthesized in late spermatids but are formed in earlier developmental stages and are thereafter preserved in the acrosome. The enhancement of lectin binding caused by Bouin's fixative might also be applied to other tissues where previous experiments with formalin fixed tissue have failed to show any staining.