Glycoconjugate Content Research Articles

Comparative Analysis of Free and Glycoconjugates Oligosaccharide Content in Milk from Different Species.

Human milk is important for infant growth, and oligosaccharides are one of its main functional nutrients. To enable a systematic comparison of free oligosaccharide and glycoconjugate content in milk from different species, the phenol-sulfuric acid and resorcinol assays were combined to determine the content. Using real samples, the method revealed that human milk contained the highest amount of total, neutral (9.84 ± 0.31 g/L), and sialylated (3.21 ± 0.11 g/L) free oligosaccharides, followed by goat milk, with neutral (0.135 ± 0.015 g/L) and sialylated (0.192 ± 0.016 g/L) free oligosaccharides and at a distance by bovine and yak milk. The highest total glycoconjugate content was detected in yak milk (0.798 ± 0.011 g/L), followed by human, bovine, and goat milk. These findings suggest that goat milk is the best source of free oligosaccharides in infant formula and functional dairy products and yak milk is the best source of glycoconjugates.

Glycoconjugate content quantification to assess vaccine potency: A simplified approach

Several glycoconjugate vaccines have been licensed or are currently in clinical development to prevent bacterial infections.Here we report the development of a single analytical assay to quantify the conjugated saccharide content, as alternative to two separated total and free (unconjugated) saccharide assays used so far, for a quadrivalent conjugate vaccine containing meningococcal serogroup A polysaccharide (α-1,6-linked N-acetylmannosamine phosphate repeating unit partly O-acetylated at position C3 or C4) coupled with CRM197 protein.The results confirm a high linear correlation among the two approaches (conjugated saccharide content vs. difference of total saccharide and free saccharide).Conjugated saccharide content estimation is therefore demonstrated to be a suitable method to monitor the product quality of vaccines containing meningococcal serogroup A conjugate antigen, in the final filled presentation as demonstrated here and potentially on the bulk conjugate before formulation.

Neuroprotective effects of vitamin C and garlic on glycoconjugates changes of cerebellar cortex in lead-exposed rat offspring

The deteriorating effects of Lead (Pb) on central nervous system (CNS) such as cerebellum has been demonstrated in previous studies. Glycoconjugates with the important role in CNS development may be affected by Pb-exposure. Utilization of antioxidant agents and herbal plants has attracted a great deal of attention on attenuating neurotoxicants-induced damage. Thus, in this study the neuroprotective effects of vitamin C and garlic on content of glycoconjugates of cerebellar cortex in Pb-exposed animals were investigated. Wistar pregnant rats were divided into: control (C), Pb-exposed (Pb) (1500 ppm lead acetate in drinking water), Pb plus vitamin C (Pb + Vit C) (500 mg/kg) intraperitoneally, Pb plus garlic (Pb + G) (1 mL /100 g body weight fresh garlic juice via gavage), Pb plus vitamin C and garlic (Pb + Vit C + G), and sham groups (Sh). Finally, levels of Pb in blood were measured in both rats and offspring on postnatal day 50 (PND50). Also, the cerebellums were removed for measuring Pb-levels and performing lectin histochemistry. Blood and cerebellar Pb-levels were increased in Pb-exposed group compared to control group (P < 0.001), whereas they were decreased significantly in Pb + Vit C, Pb + G, and Pb + Vit C + G groups (P < 0.01). By using MPA, UEA-1, and WGA lectin histochemistry, Pb-exposed group showed weak staining intensity compared to other groups. Besides, significant decrease was observed in the density of lectin-positive neurons of Pb-exposed group compared to the control group (P < 0.001). Moreover, strong staining intensity and high lectin-positive neurons were found in Pb + Vit C, Pb + G and Pb + Vit C + G groups than Pb-exposed group (P < 0.001). The present study revealed that Pb-exposure can result in alteration in the cerebellar glycoconjugates contents and co-administration of vitamin C and garlic could attenuate the adverse effects of Pb. The findings of this study revealed the ameliorating effects of vitamin C and garlic against Pb, suggesting the potential use of vitamin C and garlic as preventive agents in Pb poisoning.

The synovial surface of the articular cartilage.

The articular cartilage has been the subject of a huge amount of research carried out with a wide array of different techniques. Most of the existing morphological and ultrastructural data on this tissue, however, were obtained either by light microscopy or by transmission electron microscopy. Both techniques rely on thin sections and neither allows a direct, face-on visualization of the free cartilage surface (synovial surface), which is the only portion subject to frictional as well as compressive forces. In the present research, high resolution visualization by scanning electron microscopy and by atomic force microscopy revealed that the collagen fibrils of the articular surface are exclusively represented by thin, uniform, parallel fibrils evocative of the heterotypic type IX-type II fibrils reported by other authors, immersed in an abundant matrix of glycoconjugates, in part regularly arranged in phase with the D-period of collagen. Electrophoresis of fluorophore-labeled saccharides confirmed that the superficial and the deeper layers are quite different in their glycoconjugate content as well, the deeper ones containing more sulfated, more acidic small proteoglycans bound to thicker, more heterogeneous collagen fibrils. The differences found between the synovial surface and the deeper layers are consistent with the different mechanical stresses they must withstand.

Lectin Profile Variation in Mesenchymal Stem Cells Derived from Different Sources

Human mesenchymal stem cells (MSCs), a promising source of stem cells for regenerative medicine, have different morphological and functional characteristics. Carbohydrate moieties on the cell surface play an important role, including cell-cell interaction and cell recognition. The objective of this study was to determine possible differences in glycoconjugate distribution patterns of MSCs derived from various sources. MSCs were isolated from adipose tissue, bone marrow, Wharton’s jelly, and cord blood. Then, they were stained with FITC-conjugated wheat germ agglutinin (WGA), peanut agglutinin (PNA), concanavalin A (ConA), Ulex europaeus (UEA), Dolichos biflorus (DBA), and Atto-488 conjugated Phytolacca americana (PWM) lectins. The intensity of the reactions was scored using ImageJ software. Flow cytometry was performed to detect the expression of the endothelial marker CD144. The obtained data were analyzed by ANOVA and LSD. Cord blood-derived MSCs showed the most significant staining intensities with all lectins. All MSCs were also moderately stained with PNA. Bone marrow-derived MSCs failed to react with UEA, DBA, and ConA. Wharton’s jelly-derived MSCs could also not be stained with ConA. Cord blood-derived MSCs contained 2 subpopulations: osteoclast- and fibroblast-like cells. Both lectin staining intensity and distribution pattern were different in these 2 cell types; therefore, the central part of osteoclast-like cells stained more intensive with PNA and PWM, while that part in fibroblast-like cells stained more intensive with ConA. None of them expressed CD144. The glycoconjugate content of MSCs derived from various sources is different.

Chondroitin sulfate isolated from the secretion of the venom-producing parotoid gland of Brazilian bufonid

The parotoid gland of bufonids is characterized as a specialized integument region, formed by different gland types. The secretion elaborated by the largest glandular alveoli has been related to animal chemical defense and is constituted by granular protein content, associated with a basophilic and alcianophilic material with features of glycoconjugates. This study aimed to identify and characterize the glycoconjugates in the secretion of the largest granular gland of the parotoid gland of Rinella icterica by histochemical and immunohistochemical techniques at light microscopy, biochemical methods, and nuclear magnetic resonance spectroscopy. Our results showed that the glycoconjugate content contains a mixture of chondroitin‑6‑sulfate (C6S) and chondroitin-non-sulfate (C0S). Thus, chondroitin sulfate probably plays an important role in gland physiology, probably protecting the protein content while inside the secretory portion.

Different Glycoconjugate Content in Mucus Secreting Cells of the Rat Fundic Gastric Glands.

The fundic glands of the stomach contain two types of mucous cells: surface mucous cells (SMCs) located at the surface of the stomach and the pits, and mucous neck cells (MNCs) situated in the neck of the glands. They produce mucins, highly glycosylated proteins. Very little is known about the glycan composition of these mucins and of gastric secretion in general. We used several lectins combined with deglycosylation pretreatments to analyze the glycan composition of SMCs and MNCs. The results showed the presence of terminal sialic acid and subterminal Gal and GalNAc, which is consistent with previous knowledge about glycosylation in mucins. Our results also support previous reports that showed a different expression of mucins in the SMCs, depending on their superficial or deep location in the pit. Some lectins labeled only the perinuclear region of the SMCs, but not the apical region, where the secretory granules are stored. This suggests that the lectins are labeling sugar residues that are accessible to lectins during the first steps of glycan synthesis, which occurs in the endoplasmic reticulum and Golgi apparatus. Our results indicate that SMCs and MNCs produce a mucus secretion with a different glycoconjugate composition. The secretion is more varied in SMCs. As our results coincide with what we know about glycosylation of mucins, we can conclude that most of the glycans detected belong to mucins, and the differences in glycosylation observed in each cell type may be due, mainly, to the different secreted mucins. Anat Rec, 301:2128-2144, 2018. © 2018 Wiley Periodicals, Inc.

Small Molecules Targeting Human N-Acetylmannosamine Kinase.

N-Acetylmannosamine kinase (MNK) plays a key role in the biosynthesis of sialic acids and glycosylation of proteins. Sialylated glycoconjugates affect a large number of biological processes, including immune modulation and cancer transformation. In search of effective inhibitors of MNK we applied high-throughput screening of drug-like small molecules. By applying different orthogonal assays for their validation we identified four potential MNK-specific inhibitors with IC50 values in the low-micromolar range. Molecular modelling of the inhibitors into the active site of MNK supports their binding to the sugar or the ATP-binding pocket of the enzyme or both. These compounds are promising for downregulation of the sialic acid content of glycoconjugates and for studying the functional contribution of sialic acids to disease development.

Comprehensive Analytical Approach toward Glycomic Characterization and Profiling in Urinary Exosomes.

Exosomes are extracellular nanosized vesicles with lipid bilayers encapsulating nucleic acids and proteins, both with and without glycosylation. While exosomal nucleic acids and proteins have previously been explored to identify cancer biomarkers with some promising results, little information has been available concerning their glycoconjugate content. Exosomes were isolated from normal urine samples through multistep differential centrifugation. The isolated exosomes have an average size of 146 nm and a spherical shape, as determined by dynamic light scattering and transmission electron microscopy, respectively. N-Glycans were enzymatically released from the isolated vesicles. After being reduced and permethylated, N-glycans were measured by MALDI mass spectrometry. Paucimannosidic, high-mannose, and complex type glycans were identified and their relative abundances were determined. Some detailed structures of these glycans were revealed through liquid chromatography/tandem mass spectrometry (LC/MS-MS). The reduced N-glycans, without being permethylated, were also separated and analyzed by LC/MS-MS, and their structures were further detailed through isomeric separation on porous graphitized carbon (PGC) packed in long capillaries. Using microfractionation before LC/MS-MS, minor multiantennary N-glycans were preconcentrated as based on hydrophobicity or charge. Preconcentration of the reduced and permethylated glycans on a C18 cartridge revealed numerous large glycans, whereas fractionation of the reduced N-glycans by ion-exchange cartridges facilitated detection of sulfated glycans. After removing N-glycans from the original sample aliquot, O-glycans were chemically released from urinary exosomes and profiled, revealing some unusual structures.

Aroma potential of oak battens prepared from decommissioned oak barrels.

During barrel maturation, volatile compounds are extracted from oak wood and impart aroma and flavor to wine, enhancing its character and complexity. However, barrels contain a finite pool of extractable material, which diminishes with time. As a consequence, most barrels are decommissioned after 5 or 6 years. This study investigated whether or not decommissioned barrels can be "reclaimed" and utilized as a previously untapped source of quality oak for wine maturation. Oak battens were prepared from staves of decommissioned French and American oak barrels, and their composition analyzed before and after toasting. The oak lactone glycoconjugate content of untoasted reclaimed oak was determined by liquid chromatography-tandem mass spectrometry, while the concentrations of cis- and trans-oak lactone, guaiacol, 4-methlyguaiacol, vanillin, eugenol, furfural, and 5-methylfurfural present in toasted reclaimed oak were determined by gas chromatography-mass spectrometry. Aroma potential was then evaluated by comparing the composition of reclaimed oak with that of new oak. Comparable levels of oak lactone glycoconjugates and oak volatiles were observed, demonstrating the aroma potential of reclaimed oak and therefore its suitability as a raw material for alternative oak products, i.e., chips or battens, for the maturation of wine. The temperature profiles achieved during toasting were also measured to evaluate the viability of any yeast or bacteria present in reclaimed oak.

The outer mantle epithelium of Haliotis tuberculata (Gastropoda Haliotidae): an ultrastructural and histochemical study using lectins

AbstractThe mantle of molluscs has been the subject of many studies as it is the organ that forms the shell. Microscopic studies in particular focus on the outer mantle epithelium, but few studies address this epithelium in a histochemical way. In this study, the outer mantle epithelium in adult specimens of Haliotis tuberculata is studied, that is, in specimens involved in maintaining and repairing the shell rather than in generating it. The epithelial cells are studied by scanning (SEM) and transmission electron microscopy (TEM), and by histochemical techniques, including the use of lectins for their biochemical characterization. The epithelium is composed of pigmented epidermal cells with small microvilli and junctional complexes. It furthermore contains a few ciliated cells, as well as two types of secretory cells which differ in the ultrastructural appearance of their secretory granules and their glycoconjugate content. Histochemical study shows secretory cells containing sulphated glycoconjugates such as glycosaminoglycans or mucins rich in N‐acetylgalactosamine and N‐glycoproteins rich in fucose. Furthermore, the apical regions of the epidermal cells are positive for lectins that label fucose, mannose and N‐acetylglucosamine. The role of epithelial cells in the synthesis of structural components of the shell is discussed.

Rebamipide Increases the Mucin-Like Glycoprotein Production in Corneal Epithelial Cells

Dry eye is a multifactorial disease of tears and the ocular surface due to tear deficiency or excessive tear evaporation. Tear film instability is due to a disturbance in ocular surface mucin leading to a dysfunction of mucin, resulting in dry eye. In this study, we examined the effect of rebamipide, an anti-ulcer agent, on glycoconjugate production, as an indicator of mucin-like glycoprotein in cultured corneal epithelial cells. Further, we investigated the effect of rebamipide on the gene expression of membrane-associated mucins. Confluent cultured human corneal epithelial cells were incubated with rebamipide for 24 h. The glycoconjugate content in the supernatant and the cell extracts was measured by wheat germ agglutinin-enzyme-linked lectin assay combined gel-filtration method. In the experiment on mucin gene expression, cultured human corneal epithelial cells were collected at 0, 3, 6, and 12 h after administration of rebamipide. Real-time quantitative polymerase chain reaction was used to analyze the quantity of MUC1, MUC 4, and MUC16 gene expression. Rebamipide significantly increased the glycoconjugate contents in the supernatant and cell extract. In the mucin gene expression in the cells, rebamipide increased MUC1 and MUC4 gene expression, but did not increase MUC16 gene expression. Rebamipide promoted glycoconjugate, which has a property as a mucin-like glycoprotein, in human corneal epithelial cells. The increased production was mediated by MUC1 and MUC4 gene expression.

Lectin Binding Pattern of Gastric Mucosa of Pacific White-Sided Dolphin, Lagenorhynchus obliquidens

The stomach of the Pacific white-sided dolphin is divided into three parts: forestomach, proper gastric gland portion, and pyloric chamber. The histological features of the dolphin stomach are similar to those of terrestrial mammal stomachs, although the distribution of glycoconjugates in mucosal cells of the dolphin stomach is unknown. To learn about glycoconjugates in cetacean gastric mucosa, the glycoconjugate distribution in the mucous epithelium of the Pacific white-sided dolphin was studied using 21 lectins. Among the lectins tested, GSL-I and DBA specifically labelled the superficial layer of the forestomach epithelium. GSL-I, SBA, RCA-I, VVA, GSL-II, DSL, LEL, STL, s-WGA, WGA, PNA, and Jacalin labelled the luminal surface of the chief cells in the proper gastric gland. GSL-I, SBA, RCA-I, DSL, LEL, STL, s-WGA, PNA, and LCA labelled tubular structures in the cytoplasm of parietal cells. The surface portion of the pits in the pyloric chamber strongly reacted with RCA-I, GSL-II, WGA, PNA, LCA, PHA-L, and UEA-I, whereas the neck portion reacted weakly. Although lining one tubular portion, individual secretory cells in the pyloric gland displayed a heterogeneous reaction. This is the first report on the lectin histochemistry of a cetacean stomach and reveals GSL-I and DBA as specific marker lectins for the cornified stratified squamous epithelium cells of the Pacific white-sided dolphin. The stomachs of cetaceans and terrestrial mammals have similar histological features and mucous glycoconjugate content.

Comparison of methods for the analysis of smoke related phenols and their conjugates in grapes and wine

Background and Aims: Australian grape growers and winemakers have typically relied on guaiacol and 4-methylguaiacol measurements to determine smoke exposure of grapes following bushfires or prescribed burns. However, the guaiacol and 4-methylguaiacol content of grapes does not always correlate with the extent of taint in resultant wines. This study compared several methods for the analysis of smoke related phenols and their conjugates in grapes and wine, to determine their capacity as diagnostic assays for smoke exposure. Methods and Results: Smoke-affected grapes were sourced from commercial vineyards exposed to bushfire smoke and from experimental field trials involving the application of smoke to grapevines, and small-scale wines were made from a number of these samples. Several analytical methods were applied to grapes and wine to determine the concentration of smoke related phenols and their conjugates. Strong correlations were observed between the glycoconjugate content of smoke-affected grapes and the concentration of guaiacol and 4-methylguaiacol released following acid hydrolysis of juice. Conclusions: Where smoke-affected grapes contain low or non-detectable levels of guaiacol and 4-methylguaiacol, analytical methods that quantify their glycoconjugate forms (either directly or indirectly) provide a better indication of the extent of smoke exposure. Significance of the Study: This is the first study to compare different methods for assessing smoke exposure in grapes and wine, through analysis of free and bound guaiacol and 4-methylguaiacol. These methods will allow grape growers and winemakers to more reliably assess smoke exposure of grapes, enabling better informed decisions to be made with regards to harvesting and processing smoke-affected grapes.

Excessive glycation of pericapillary pericytic matrix components is an essential mechanism of arterial hypertension development in hyperglycemia

In patients with essential hypertension, inhibition of glucose utilization in tissues was detected similar to that in diabetics. High levels of glycated compounds were found in cerebral, cardiac, and renal tissues of patients dead from coronary heart disease complicated and not complicated from diabetes mellitus and essential hypertension compared to victims dead from traumas. Experimental studies on rabbits and rats showed that the content of glycoconjugates in tissues did not increase in short-term (exogenous or stress-associated) hyperglycemia, while accumulation of glycoconjugates in pericapillary, pericytic, and cellular structures in long-term hyperglycemia caused deformation of tissue ultrastructure. These disorders can impede capillary transudation, initiate and stabilize arterial hypertension, and lead to multiple organ failure.

Tectorial Membrane Material Properties in Tecta Y1870 C/+ Heterozygous Mice

The solid component of the tectorial membrane (TM) is a porous matrix made up of the radial collagen fibers and the striated sheet matrix. The striated sheet matrix is believed to contribute to shear impedance in both the radial and longitudinal directions, but the molecular mechanisms involved have not been determined. A missense mutation in Tecta, a gene that encodes for the α-tectorin protein in the striated sheet matrix, causes a 60-dB threshold shift in mice with relatively little reduction in outer hair cell amplification. Here, we show that this threshold shift is coupled to changes in shear impedance, response to osmotic pressure, and concentration of fixed charge of the TM. In Tecta Y 1870 C/+ mice, the tectorin content of the TM was reduced, as was the content of glycoconjugates reacting with the lectin wheat germ agglutinin. Charge measurements showed a decrease in fixed charge concentration from − 6.4 ± 1.4 mmol/L in wild-types to − 2.1 ± 0.7 mmol/L in Tecta Y 1870 C/+ TMs. TMs from Tecta Y 1870 C/+ mice showed little volume change in response to osmotic pressure compared to those of wild-type mice. The magnitude of both radial and longitudinal TM shear impedance was reduced by 10 ± 1.6 dB in Tecta Y 1870 C/+ mice. However, the phase of shear impedance was unchanged. These changes are consistent with an increase in the porosity of the TM and a corresponding decrease of the solid fraction. Mechanisms by which these changes can affect the coupling between outer and inner hair cells are discussed.

LPS-induced cytokine production in human dendritic cells is regulated by sialidase activity

Removal of sialic acid from glycoconjugates on the surface of monocytes enhances their response to bacterial LPS. We tested the hypothesis that endogenous sialidase activity creates a permissive state for LPS-induced cytokine production in human monocyte-derived DCs. Of the four genetically distinct sialidases (Neu1-4), Neu1, Neu3, and Neu4 are expressed in human monocytes, but only Neu1 and Neu3 are up-regulated as cells differentiate into DCs. Neu1 and Neu3 are present on the surface of monocytes and DCs and are also present intracellularly. DCs contain a greater amount of sialic acid than monocytes, but the amount of sialic acid/mg total protein declines during differentiation to DCs. This relative hyposialylation of cells does not occur in mature DCs grown in the presence of zanamivir, a pharmacologic inhibitor of Neu3 but not Neu1, or DANA, an inhibitor of Neu1 and Neu3. Inhibition of sialidase activity during differentiation to DCs causes no detectable change in cell viability or expression of DC surface markers. Differentiation of monocytes into DCs in the presence of zanamivir results in reduced LPS- induced expression of IL-6, IL-12p40, and TNF-α by mature DCs, demonstrating a role for Neu3 in cytokine production. A role for Neu3 is supported by inhibition of cytokine production by DANA in DCs from Neu1⁻/⁻ and WT mice. We conclude that sialidase-mediated change in sialic acid content of specific cell surface glycoconjugates in DCs regulates LPS-induced cytokine production, thereby contributing to development of adaptive immune responses.

Avian Semen Cryopreservation: What Are the Biological Challenges?

The value of the ability to cryopreserve and store germplasm has long been recognized for indefinite preservation of genetic material, especially for at-risk populations. In contrast to domestic livestock species, cryogenic storage of poultry semen is not reliable enough for germplasm preservation. The relatively low fertilizing ability of frozen/thawed poultry sperm most likely results from physiological sensitivity to the cryogenic process coupled with the requirement for prolonged sperm functionality in the hen reproductive tract; however, the concept of defining these physiological challenges has been underemphasized. For example, alterations in membrane carbohydrate content and diminished energy production in frozen/thawed sperm have important implications for successful gamete interaction. Recent data suggests that both glycoconjugate content and adenosine triphosphate (ATP) generation are affected by cryopreservation. Moreover, susceptibility to the cryogenic process seems to vary among lines and strains of birds, as illustrated by line-specific differences in ATP concentrations of frozen/thawed sperm from pedigreed commercial layers. Research based on biochemical and molecular comparisons of sperm among lines may lead to identification of factors that influence the freezability of poultry semen.

Morphology and Glycoconjugate Content of Opossum Esophageal Epithelium and Glands: Regional Heterogeneity and Effects of Acid-Induced Mucosal Injury and Recovery

This study examined the regional heterogeneity and site-specific changes in histology and glycoconjugate content following the induction of esophagitis and after recovery in an established animal model. Esophageal samples were excised from five sites in anesthetized opossums 24 hr after 3 consecutive days of 45-min perfusion with saline or 100 mM HCl or 1 week after acid in recovery animals. Controls exhibited significant regional differences in epithelial thickness, gland volume, glycoconjugate composition, and mast cell numbers. Acid perfusion induced erosive esophagitis and significant epithelial denudation throughout the distal 7 cm, combined with significant site-specific increases in gland lumen volume, decreases in mast cell numbers, and changes in glycoconjugate content. No differences from controls were noted in recovery animals, except for a significant increase in epithelial thickness and change in glycoconjugate content in the distal 2 cm. The results of this study highlight the impact of acid exposure on these structural defenses, but further investigation is required to explore the importance of these acid-induced changes in the pathogenesis of reflux esophagitis.

Complex carbohydrates occurring in the digestive apparatus of Umbrina cirrosa (L.) fry.

The glycosoaminoglycans in the digestive apparatus of immature fish have important biological functions and are involved in morphofunctional differentiation. The aim of this study was to investigate the glycoconjugate histochemistry in the different parts of the digestive apparatus (oesophagus, stomach, intestine) of Umbrina cirrosa (L.) fry using classical histochemical reactions (periodic acid-Schiff, Alcian blue pH 2.5, Alcian blue/periodic acid-Schiff, high iron diamine, low iron diamine) in conjunction with glycolytic digestions that degrade different classes of glycosoaminoglycans. No differences were observed in the reactivity to conventional histochemical staining of the oesophagus, stomach or intestine among 27-, 34- or 44-day-old fry. In the oesophagus, the mucopolysaccharides contained chondroitin sulphates B and A and/or C, heparan sulphate and chondroitin. In the stomach, only neutral glycoconjugates were revealed, whereas in the intestine there were only chondroitin sulphates. Some differences in the type and content of glycoconjugates were found in Umbrina cirrosa (L.) fry compared to those of adult subjects, probably related to different dietary habits and to changes in the environmental conditions.