Histochemical analysis of changes in lectin binding in murine glomerular lesions

Lectin binding in diseased murine glomeruli was studied in MRL/1 mice, using seven different fluorescence- or peroxidase-coupled lectins: Griffonia simplicifolia I (GS-I), Ulex europaeus agglutinin I (UEA-I), Ricinus communis agglutinin I (RCA-I), wheat germ agglutinin (WGA), concanavalin A (Con A), peanut agglutinin (PNA), and Helix pomatia agglutinin (HPA). Lectin binding in diseased glomeruli of MRL/1 mice was different from that in normal glomeruli. Light and fluorescence microscopy showed that: 1. in mesangial proliferative lesions, the binding of RCA-I, WGA and Con A increased and that of GS-I and PNA appeared in the mesangium; 2. in other glomerular lesions, UEA-I binding appeared and RCA-I stained the altered membranes irregularly. Electron microscopy showed that: 1. GS-I stained the endothelial cell coat and the glomerular basement membrane covered by the endothelial cells; 2. GS-I strongly stained the dilated subendothelium in regions of mild mesangial interposition; 3. GS-I stained the cell coat of invasive macrophages; 4. GS-I and UEA-I stained the cell membrane-like material derived from degenerative endothelial cells; 5. RCA-I stained the epithelial and endothelial cell coats and the glomerular basement membrane. These results indicate that lectin-binding studies can be used for analysis of glomerular lesions.     

Histochemical Analysis of Changes in Lectin Binding in Murine Glomerular Lesions

Lectin binding in diseased murine glomeruli was studied in MRL 1 mice, using seven different fluorescence- or peroxidase coupled lectins: Griffonia simplicifolia I (GS-I) , Ulex europaeus agglutinin I (UEA-I) , Ricinus communis agglutinin I (RCA I), wheat germ agglutinin (WGA), concanavalin A (Con A), peanut agglutinin (PNA), and Helix pomatia agglutinin (HPA). Lectin binding in diseased glomeruli of MRL 1 mice was different from that in normal glomeruli. Light and fluorescence microscopy showed that: 1. in mesangial proliferative lesions, the binding of RCA I, WGA and Con A increased and that of GS I and PNA appeared in the mesangium; 2. in other glomerular lesions, UEA-I bindng appeared and RCA I stained the altered membranes irregularly. Electon microscopy showed that: 1. GS-I stained the endothelial cell coat and the glomerular basement membrane covered by the endothelial cells; 2. GS I strongly stained the dilated subendothelium in regions of mild mesangial interposition; 3. GS-I stained the cell coat of invasive macrophages; 4. GS-I and UEA-I stained the cell membrane-like material derived from degenerative endothelial cells; 5. RCA I stained the epithelial and endothelial cell coats and the glomerular basement membrane. These results indicate that lectin-binding studies can be used for analysis of glomerular lesions.     

Ultrastructural localization of monosaccharide residues on cerebral endothelium

Biotinylated lectins were used to localize oligosaccharides on the luminal plasma membrane of endothelium of intracerebral cortical vessels. Binding of concanavalin A, wheat germ and Ricinus communis-I was observed on the endothelial luminal plasma membrane of cerebral arterioles and capillaries indicating the presence of alpha-D-mannosyl, alpha-D-glucosyl, beta-N-acetylglucosaminyl, sialyl, and beta-D-galactosyl residues. Lectin binding occurred on the plasma membrane of pinocytotic vesicles open to the vascular lumen and on membranes at the luminal end of interendothelial junctions but not on membranes within junctions. Higher concentrations of Ulex europaeus-I, soybean, and Dolichos biflorus agglutinins were required to demonstrate the alpha-L-fucosyl and alpha-N-acetyl-D-galactosaminyl residues. Pretreatment of brain slices with neuraminidase accentuated the staining produced by soybean agglutinin and resulted in exposure of peanut agglutinin-binding sites on endothelium of arterioles and capillaries. In this respect cerebral endothelium differs from noncerebral endothelium which binds peanut agglutinin without prior neuraminidase pretreatment. The role of these saccharide residues in endothelial permeability and charge remains to be determined.     

Normal adaptation of pulmonary arterial intima to extrauterine life in the pig: ultrastructural studies

Adaptation of the pulmonary arterial intima was studied in injected lung specimens of 34 Large White pigs. Each type of pre- and intra-acinar artery was studied separately using transmission and scanning electron microscopy. Determination of the endothelial surface/volume ratio and volume densities of (1) endothelium and subendothelium, (2) endothelial cytoplasmic organelles and (3) subendothelial connective tissue elements yielded 6832 measurements which comprised a computerized database. At birth, endothelial cell morphology changed more rapidly and to a greater extent in peripheral than in proximal arteries. Endothelial surface/volume ratio increased (p less than 0.0001). Fetal surface projections, junctional interdigitations and overlap became less evident. Adaptational changes were complete in three weeks. Between three weeks and adulthood a reduction in endothelial surface/volume ratio suggested cell growth. In the subendothelium the volume density of collagen and basement membrane and elastin increased (p less than 0.001). The internal elastic lamina, immature in all arteries at birth increased in thickness and integrity until in the adult, only in small muscular arteries did gaps between elastin profiles ensure frequent contact between endothelial and smooth muscle cells. At all ages regional differences in endothelial cell morphology were evident.     

Tissue‐specific venous expression of the EPH family receptor EphB1 in the skin vasculature

Background : The major arteries and veins are formed early during development. The molecular tools to identify arterial and venous endothelial cells improve our understanding of arterial–venous differentiation and branching morphogenesis. Compared with arterial differentiation, relatively little is known about what controls venous development, due to lack of definitive molecular markers for venous endothelial cells. Results: Here we report that the antibody against EphB1, an EphB class receptor, makes it possible to establish a reliable whole‐mount immunohistochemical analysis of venous identity with greater resolution than previously possible in embryonic and adult skin vasculature models. EphB1 expression is restricted to the entire venous vasculature throughout embryonic development to adulthood, whereas the previously established venous marker EphB4 is also detectable in lymphatic vasculature. This venous‐restricted expression of EphB1 is established after the vascular remodeling of the primary capillary plexus has occurred. Compared with its venous‐specific expression in the skin, however, EphB1 is not restricted to the venous vasculature in yolk sac, trunk and lung. Conclusions: These studies introduce EphB1 as a new venous‐restricted marker in a tissue‐specific and time‐dependent manner. Developmental Dynamics 242:976–988, 2013. © 2013 Wiley Periodicals, Inc.     

Histochemical characterization of lectin binding in mouse cerebellum

Eight fluorescein-isothiocyanate-conjugated lectins differing from each other in carbohydrate binding specificities have been used to reveal qualitative differences in carbohydrate composition among the various cell types of the early postnatal and adult cerebellar cortex, cerebellar deep nuclei and medulla. By treating unfixed frozen tissue sections with unconjugated lectin in the presence of excess hapten sugar and subsequently staining with fluorescein-isothiocyanate-conjugated lectin in the presence of bovine serum albumin, carbohydrate specific staining was observed for all of the lectins studied. Lectin binding was selectively inhibited by appropriate hapten sugars. For several lectins (wheat germ agglutinin, Ricinus communis agglutinins and Lens culinaris agglutinins) complex carbohydrates were required for inhibition of staining.In the adult cerebellum, concanavalin A intensely stained the soma of granule cells, synaptic glomeruli and the cytoplasm of Purkinje cells, while the molecular layer and white matter were relatively unstained. Wheat germ agglutinin heavily labeled the soma of granule cells, synaptic glomeruli, parallel fibers of the molecular layer, and the nuclear membrane of Purkinje cells, and weakly labeled the white matter. Ricinus communis agglutins (m.w. 60,000 and 120,000) intensely stained the soma of granule cells, synaptic glomeruli, parallel fibers in the molecular layer, the cytoplasm of Purkinje cells, and the white matter. None of the above lectins stained Purkinje cell dendrites. Lens culinaris lectins A and B stained the soma of granule cells, synaptic glomeruli, the cytoplasm of Purkinje cells, Purkinje cell dendrites, and white matter.In the 5- and 12-day-old postnatal cerebellum, concanavalin A stained the molecular layer more strongly than in the adult. Concanavalin A, wheat germ agglutinin and Lens culinaris lectins moderately stained cell cytoplasm in the external and internal granule layers, but the external granule cell layer was heavily labeled with both Ricinus communis lectins. With the soybean agglutinin, weak staining of the molecular layer and synaptic glomeruli was detected in young cerebellum, in contrast to adult tissue where no staining was observed. No labeling of the young or adult cerebellum was observed with Ulex europaeus agglutinin I.The specific patterns of staining with different lectins probably reflect the different carbohydrate compositions of the various cell types and perhaps of the intercellular matrix.     

Lectin histochemistry of human fetal notochord, ecchordosis physaliphora, and chordomas.

Lectin histochemical studies of human fetal notochord, ecchordosis physaliphora, and eight chordomas were performed. Ecchordosis physaliphora and eight chordomas were stained with Ricinus communis type I, Canavalia ensiformis, Triticum vulgaris, and Limax flavus. Ricinus communis type I, T vulgaris, and L flavus reacted with both tumor cells and the extracellular mucinous matrix, while C ensiformis mainly reacted with the cytoplasm of tumor cells. Thus, tumor cells were most recognizable with the C ensiformis stain. After neuraminidase treatment, ecchordosis physaliphora and chordomas invariably showed positivities for Arachis hypogaea. The lectin-binding patterns of chordomas closely reflected those of the human fetal notochord. Chordomas were completely sialylated regardless of either the clinical course or histopathological findings. Among the eight lectins, C ensiformis heavily labeled chordoma cells but not extracellular space. This was probably because asparagine-linked N-glycosylation was active in the chordomas, while the high-mannose-type oligosaccharides were apt to remain in the cytoplasm.     

Identification of the connective tissues synthesized by the venous and arterial endothelia of the human umbilical cord: a comparative study

Immunocytochemistry has been used to identify endothelial cells in sections of human umbilical cord and in cultures of the venous and arterial endothelium, using Factor VIII and Ulex europaeus as endothelial markers. The connective tissue components, including various collagen types, fibronectin and laminin, were identified and localized in the cord and in both venous and arterial cultured endothelium. Interstitial collagens synthesized by the cultured cells were isolated and quantified. Angiogenic ability was examined. The effect of a noxious stimulus, 24 h hypoxia, was quantified in cultured venous endothelium. The results showed that cultured arterial endothelium possesses a vacuolated cytoplasm which is absent in venous endothelium. The major collagens observed in venous culture were types III and V; the latter was found mainly in the cell layer. Venous endothelium was angiogenic. It responded to hypoxia by producing fewer cells, more protein/10(6) cells but less collagen, both in absolute terms and as a percentage of protein/10(6) cells, thus behaving like cultured porcine and bovine aortic endothelium. Fibronectin was the major 'glue' associated with endothelium. We conclude that culture can reveal the synthetic potential of endothelium which the cord itself does not often show; moreover culture appears essential to demonstrate that arterial and venous endothelium behave differently from each other.     

Kinetics of serotonin uptake in the intact lung

The pulmonary endothelium is capable of removing and metabolizing serotonin (5HT) carried in the venous blood. Thus the lungs can influence the arterial concentrations of 5HT. In addition, there is evidence that changes in the lung uptake of 5HT might portend more serious endothelial damage wherein the barrier function of the endothelium is compromised. This has been a stimulus for finding methods for evaluating these endothelial functions. These methods must be able to distinguish changes in whole organ function which result from changes in perfusion (e.g., cardiac output, redistribution of flow, etc.) from those resulting from changes in the function of the endothelial cells. When a bolus containing radio-labeled 5HT and an unmetabolizable indicator which is confined to the vascular space is injected into the pulmonary artery, the pulmonary venous or systemic arterial concentration curves contain information about both the convective transport and endothelial cell process involved. Some of this information can be interpreted quantitatively using a simple mathematical model.     

Distribution of cell surface glycoconjugates during secondary neurulation in the chick embryo

Lectin histochemistry was used to examine the expression of cell surface glycoconjugates during secondary neurulation in chick embryos. Fourteen lectins were applied to serial sections of the caudal region of embryos at the various stages of tail bud development. The lectins Bandeiraea simplicifolia, Dolichos biflorus agglutinin, Phaseolus vulgaris leukoagglutinin, soybean agglutinin, Sophora japonica agglutinin, Ulex europaeus agglutinin and succinylated wheat germ agglutinin (sWGA) showed very light or no binding to the developing medullary cord of the tail bud. With the other lectins, staining occurred throughout the early tail bud and solid medullary cord. During cavitation, however, differential expression of cell surface glycoconjugates by different cell populations was observed. The lectins concanavalin A, Lens culinaris agglutinin, Pisum sativum agglutinin, Phaseolus vulgaris erythroagglutinin, Ricinus communis agglutinin and WGA showed basic similarities in the distribution of lectin binding. Of these, the binding pattern of WGA was the most striking. As the medullary cord cells were separating into central mesenchymal and peripheral epithelial populations, WGA bound preferentially to the epithelial cells and the notochord. The lectin PNA, however, became preferentially bound to the mesenchymal cells. Heavy staining by WGA (specific for N-acetylglucosamine and sialic acid) where sWGA staining (specific for N-acetylglucosamine only) was faint suggested that WGA binding was due to the presence of sialic acid containing glycoconjugates.     

Identification of the connective tissues synthesized by the venous and arterial endothelia of the human umbilical cord: a comparative study.

Immunocytochemistry has been used to identify endothelial cells in sections of human umbilical cord and in cultures of the venous and arterial endothelium, using Factor VIII and Ulex europaeus as endothelial markers. The connective tissue components, including various collagen types, fibronectin and laminin, were identified and localized in the cord and in both venous and arterial cultured endothelium. Interstitial collagens synthesized by the cultured cells were isolated and quantified. Angiogenic ability was examined. The effect of a noxious stimulus, 24 h hypoxia, was quantified in cultured venous endothelium. The results showed that cultured arterial endothelium possesses a vacuolated cytoplasm which is absent in venous endothelium. The major collagens observed in venous culture were types III and V; the latter was found mainly in the cell layer. Venous endothelium was angiogenic. It responded to hypoxia by producing fewer cells, more protein/10(6) cells but less collagen, both in absolute terms and as a percentage of protein/10(6) cells, thus behaving like cultured porcine and bovine aortic endothelium. Fibronectin was the major ''glue'' associated with endothelium. We conclude that culture can reveal the synthetic potential of endothelium which the cord itself does not often show; moreover culture appears essential to demonstrate that arterial and venous endothelium behave differently from each other.     

Fibrous remodeling of the pulmonary venous system in pulmonary arterial hypertension associated with connective tissue diseases

Pulmonary arterial hypertension is a severe complication of connective tissue diseases. It is currently well established that pulmonary arterial hypertension associated with connective tissue diseases such as systemic sclerosis is frequently less responsive or even refractory to pulmonary vasodilator therapies. In that setting, pulmonary venoocclusive disease is believed to contribute to treatment failures. We therefore hypothesized that pulmonary arterial hypertension associated with connective tissue diseases may be associated with obstructive lesions of pulmonary veins. Lung samples from 8 patients with pulmonary arterial hypertension associated with connective tissue disease (4 limited systemic sclerosis, 2 systemic lupus erythematosus, 1 mixed connective tissue diseases, and 1 rheumatoid arthritis) were studied by light microscopy and analyzed by immunohistochemistry (5 postmortem samples, 3 explants after lung transplantation). Findings were compared with 29 pulmonary arterial hypertension cases from patients displaying neither connective tissue diseases nor associated conditions. We found that (a) 6 (75%) of 8 patients with pulmonary arterial hypertension associated with connective tissue diseases showed significant obstructive pulmonary vascular lesions predominating in veins/preseptal venules, as compared with 5 (17.2%) of 29 non-connective tissue diseases control pulmonary arterial hypertension; (b) lesions of small muscular arteries were consistently present in pulmonary arterial hypertension associated with connective tissue diseases, showing mostly intimal fibrosis and thrombotic lesions; and (c) 6 of 8 lung samples from patients with pulmonary arterial hypertension associated with connective tissue diseases revealed perivascular inflammatory infiltration. In conclusion, our study highlights the fact that pulmonary arterial hypertension complicating the course of connective tissue diseases may be characterized by a more frequent involvement of pulmonary veins and may thus explain why these patients are less prone to respond to specific pulmonary arterial hypertension treatment as compared with idiopathic pulmonary arterial hypertension.     

Lectins as a Tool for Detecting Neural Stem/Progenitor Cells in the Adult Mouse Brain

Glycoconjugates are biopolymers that are broadly distributed in the central nervous system, including the cell surface of neural stem cells or neural precursor cells (NSCs/NPCs). Glycoconjugates can be recognized by carbohydrate‐binding proteins, lectins. Two lectins, Phaseolus vulgaris lectin agglutinin E‐form (PHA‐E4) and wheat germ agglutinin (WGA) have been reported to be useful in isolating NSCs/NPCs by fluorescence‐activated cell sorting (FACS) or immunopanning methods. In this study, we analyzed the lectin‐binding properties of NSCs/NPCs in two neurogenic regions of the adult mouse brain to determine whether PHA‐E4 and WGA exhibit specific binding patterns on sections and whether there are other lectins presenting the binding pattern similar to those of PHA‐E4 and WGA in lectin histochemistry. Among nine types of lectins, peanut agglutinin was localized to the white matter and four lectins bound to cells within the subventricular zone (SVZ) of the lateral ventricle. Lectin histochemistry combined with immunohistochemistry demonstrated that one lectin, Ricinus communis agglutinin, specifically detected type A neuronal precursors and that the remaining three lectins, Agaricus bisporus agglutinin (ABA), PHA‐E4, and WGA, recognized type B NSCs and type C transient amplifying cells in the SVZ. These three lectins also recognized type 1 quiescent neural progenitors and type 2a amplifying neural progenitors in the subgranular layer of the dentate gyrus. Lectin histochemistry of the neurosphere culture also yielded similar results. These observations suggest that, in addition to PHA‐E4 and WGA, ABA lectin may also be applicable in FACS or immunopanning for the isolation of NSCs/NPCs. Anat Rec, 2011. © 2010 Wiley‐Liss, Inc.     

Mapping of the rat liver endothelial membrane with lectins and glycosylated ferritins

We explored the luminal surface of liver sinus endothelium for the presence of lectin receptors and lectinlike substances capable of interacting with specific sugars. We used ferritin-conjugated lectins and glycosylated ferritins as probes. Incubation of small blocks of rat liver with these probes led to the binding of concanavalin A (on A), Ricinus communis (RCA), wheat germ agglutinin (WGA), phytohemagglutinin (PHA) and mannosyl ferritins to the luminal surface of endothelium. Ulex europaeus agglutinin I (UEA), fucosyl, galactosyl, and chitobiosyl-ferritins did not bind. The binding was patchy and sparse in the case of Con A and mannosyl-ferritins but uniform for others. Binding density did not correlate with hemagglutinability of lectins, suggesting that the difference in the hemagglutinability of these lectins did not account for the difference in their binding densities. Bindings were all completely inhibited in the presence of excess specific sugar inhibitors, indicating the specificity of binding. The distribution of binding was segregated on the endothelial membrane, being heaviest on luminal pits. To define the functional significance of this segregated distribution, sinus endothelium was compared to portal-vein endothelium in which endothelial fenestrations are also seen; and these fenestrations as well as pits may be covered by a thin diaphragm. Of interest was the total absence of binding to the diaphragm. The significance of these findings is discussed.     

Lectin-binding to hemocytes of Mytilus edulis

Lectin receptors for WGA, Ricinus 60, Ricinus 120, and for the agglutinin from the albumin gland of Helix pomatia were detected on the surface of Mytilus hemocytes by an agglutination assay. When hemocyte monolayers on slides were incubated with these lectins, strong rosette formation was obtained after addition of human erythrocytes. The lowest lectin concentration which caused formation of rosettes was determined to be 5 micrograms/ml of WGA or of Helix agglutinin, and 20 micrograms/ml of Ricinus 60 or 40 micrograms/ml of Ricinus 120, respectively. In contrast to these results, no binding of indicator cells to Mytilus hemocytes occurred with various other lectins, including Con A.     

Light and electron microscope analysis of lectin binding to adult rat liver in situ

A comprehensive mapping of lectin receptors on adult rat liver in situ was performed at light and ultrastructural levels by using 12 biotin-labeled lectins and an avidin-biotin-peroxidase complex. In addition, concanavalin A conjugated directly to peroxidase was utilized to study intracellular membrane glycoconjugates. To achieve optimal preservation of these membrane sugar moieties, several fixatives and fixation procedures were evaluated. A periodate-lysin-paraformaldehyde combination provided the best compromise between preservation of ultrastructural details and lectin-binding reactivity. Hepatocyte cell surfaces reacted intensely with concanavalin A, Lens culinaris agglutinin, and Pisum sativum agglutinin (all specific for alpha-D-mannosyl and alpha-D-glucosyl groups) as well as Ricinus communis agglutinin type I (specific for alpha or beta-D-galactose) and wheat germ agglutinin (specific for neuraminic acid and beta-NAc-glucosaminyl groups). In addition, R. communis agglutinin and wheat germ agglutinin exhibited an extremely strong reactivity for bile canaliculi which surpassed the binding of concanavalin A, L. culinaris agglutinin, and P. sativum to these structures. Phaseolus vulgaris agglutinin (specific for beta-D-galactose-glucosyl-NAc and D-mannosyl groups), which exhibited a moderate binding to hepatocyte plasma membranes, reacted more strongly with the endothelium of sinusoids and portal vessels. Although all six of these lectins plus Bandeiraea simplicifolia stained Kupffer cells, B. simplicifolia lectin (an alpha-D-galactosyl marker) was unique in showing a strong reactivity for only this cell type. The avidin-biotin-peroxidase procedure is a sensitive method for detection of sugar moieties on cell surfaces of rat liver at both light and electron microscopic levels. In this study, the procedure was used to localize differential binding of lectins to several anatomical structures of the organ, and furthermore, we were able to map preferential localizations of carbohydrate residues in the glycocalyx of the rat hepatocyte in situ.     

Maintenance and repair of the lung endothelium does not involve contributions from marrow-derived endothelial precursor cells

Lung endothelium is believed to be a quiescent tissue with the potential to exhibit rapid and effective repair after injury. Endothelial progenitor cells derived from the bone marrow have been proposed as one source of new endothelial cells that may directly contribute to pulmonary endothelial cell homeostasis and repair. Here we use bone marrow transplantation models, using purified hematopoietic stem cells (HSCs) or unfractionated whole marrow, to assess engraftment of cells in the endothelium of a variety of tissues. We find scant evidence for any contribution of bone marrow-derived cells to the pulmonary endothelium in the steady state or after recovery from hyperoxia-induced endothelial injury. Although a rare population of CD45-/CD31+/VECadherin+ bone marrow-derived cells, originating from HSCs, can be found in lung tissue after transplantation, these cells are not readily found in anatomic locations that define the pulmonary endothelium. Moreover, by tracking transplanted bone marrow cells obtained from donor transgenic mice containing endothelial lineage-selective reporters (Tie2-GFP), no contribution of bone marrow-derived cells to the adult lung, liver, pancreas, heart, and kidney endothelium can be detected, even after prolonged follow-up periods of 11 months or after recovery from hyperoxic pulmonary endothelial injury. Our findings argue against any significant engraftment of bone marrow-derived cells in the pulmonary vascular endothelium.     

Pulmonary lymphatics and their spatial relationship to venous sphincters

Background: Pulmonary lymphatics are critical to clearing lung fluid. Although their structure can be shown with light and transmission electron microscopy, scanning electron microscopy of their casts can better show their number, size, shape, distribution, and degree of filling. This technique has identified four forms of lung lymphatics, but these forms have not been fully evaluated by tissue microscopy. A most important site of pulmonary edema formation, the pulmonary capillary, is just upstream from small veins which have focal, smooth muscle tufts termed venous sphincters. Because of their constricting potential, these sphincters may control lung perfusion and cause edema. Methods: With light and transmission electron microscopy of tissue and scanning electron microscopy of casts, the lymphatic forms were explored in relation to the tissue anatomy in rats without pulmonary edema and with mild-to-moderate edema caused by extended vascular rinsing. Results: The edematous lungs had increased sacculo-tubular lymphatics adjacent to the venous sphincters. These lymphatics were in the adventitial connective tissue and were partially endothelialized. As lymphatics became more tubular their endothelium became more complete. Collagen fibers traversed the lumen of these lymphatics even where endothelial cells were present and caused the lines on the surface of the lymphatic casts. Overlapping endothelial cells caused clefts on the casts. Conclusions: Scanning electron microscopy of lymphatic casts better defines their ultrastructure and shows the spatial relationship of veins and their sphincters to venous lymphatics. Sphincter contraction may influence pulmonary lymph production which could affect other aspects of regional lung perfusion. © 1995 Wiley-Liss, Inc.     

Bandeiraea simplicifolia lectin I and Vicia villosa agglutinin bind specifically to the vomeronasal axons in the accessory olfactory bulb of the rat.

The binding of 21 lectins to the accessory olfactory bulb (AOB) of the rat was examined by histochemistry. Two lectins [Bandeiraea simplicifolia lectin I (BSL-I) and Vicia villosa agglutinin (VVA)] bound specifically to the vomeronasal (VN) axons in the AOB. Seven lectins (Datura stramonium lectin, Erythrina cristagalli lectin, Lycoperisicon esculentum lectin, Ricinus communis agglutinin I, soybean agglutinin, Solanum tuberosum lectin, and Ulex europaeus agglutinin) bound to both VN axons in AOB and olfactory axons in the main olfactory bulb. BSL-I and VVA are useful as the marker of VN axons. This selective binding of lectins indicates the presence of specific glycoconjugates on the surface of VN axons.     

Pattern of connective tissue development in swine pulmonary vasculature by immunolocalization

Light microscopic immunolocalization studies were carried out on lung tissue from eight newborn and four adult pigs using antibodies to six extracellular matrix components. Antibodies to fibronectin, collagen type IV, and laminin localized on the same structures in adult and newborn lungs. By contrast, antibodies to the interstitial collagens (types I, III, and V) were less extensively localized in the newborn than in the adult, particularly those to type I because the fibres on which they localized in the newborn were thin and sparse. At all ages, antibodies to collagen types III and V co-localized on type I fibres and also on thin individual fibres which formed networks, more dense in the adult than in the newborn. At all ages, anti-type III collagen antibodies also localized on smooth muscle cells. In the adult, but not in the newborn, anti-type I and type V collagen antibodies localized on the connective tissue around the smooth muscle cells in the pulmonary arterial media and vein wall. The dominance of collagen type III suggests greater plasticity in the newborn pulmonary vasculature, which helps explain the recently described rapid changes in arterial wall structure which constitute adaptation to extrauterine life. The postnatal increase in collagen type I helps explain the documented postnatal increase in structural stiffness of the pulmonary arteries.