RESUMO
Selectins play an essential role in most inflammatory reactions, mediating the initial leukocyte-rolling event on activated endothelium. Heparin and dermatan sulfate (DS) bind and block P- and L-selectin function in vitro. Recently, we reported that subcutaneous administration of DS inhibits colon inflammation in rats by reducing macrophage and T-cell recruitment and macrophage activation. In the present study, we examined the effect of porcine intestinal mucosa DS on renal inflammation and fibrosis in mice after unilateral ureteral obstruction (UUO). Twenty-four adult male Swiss mice weighing 20-25 g were divided into 4 groups: group C (N = 6) was not subjected to any surgical manipulation; group SH (N = 6) was subjected to surgical manipulation but without ureter ligation; group UUO (N = 6) was subjected to unilateral ureteral obstruction and received no treatment; group UUO plus DS (N = 6) was subjected to UUO and received DS (4 mg/kg) subcutaneously daily for 14 days. An immunoblot study was also performed for TGF-ß. Collagen (stained area ~3700 µm(2)), MCP-1 (stained area ~1700 µm(2)), TGF-ß (stained area ~13% of total area), macrophage (number of cells ~40), and myofibroblast (stained area ~1900 µm(2)) levels were significantly (P < 0.05) higher in the UUO group compared to control. DS treatment significantly (P < 0.05) reduced the content of collagen (stained area ~700 µm(2)), MCP-1 (stained area ~160 µm(2)) and TGF-ß (stained area ~5% of total area), in addition to myofibroblast (stained area ~190 µm(2)) and macrophage (number of cells ~32) accumulation in the obstructed kidney. Overall, these results indicate that DS attenuates kidney inflammation by reducing macrophage recruitment, myofibroblast population and fibrosis in mice submitted to UUO.
Assuntos
Anti-Inflamatórios/farmacologia , Quimiocina CCL2/metabolismo , Dermatan Sulfato/farmacologia , Macrófagos/efeitos dos fármacos , Miofibroblastos/efeitos dos fármacos , Fator de Crescimento Transformador beta/biossíntese , Obstrução Ureteral/complicações , Animais , Anti-Inflamatórios/administração & dosagem , Dermatan Sulfato/administração & dosagem , Modelos Animais de Doenças , Fibrose , Injeções Subcutâneas , Rim/patologia , Ativação de Macrófagos , Macrófagos/metabolismo , Masculino , Camundongos , Miofibroblastos/metabolismo , Nefrite/prevenção & controle , Obstrução Ureteral/patologiaRESUMO
Selectins play an essential role in most inflammatory reactions, mediating the initial leukocyte-rolling event on activated endothelium. Heparin and dermatan sulfate (DS) bind and block P- and L-selectin function in vitro. Recently, we reported that subcutaneous administration of DS inhibits colon inflammation in rats by reducing macrophage and T-cell recruitment and macrophage activation. In the present study, we examined the effect of porcine intestinal mucosa DS on renal inflammation and fibrosis in mice after unilateral ureteral obstruction (UUO). Twenty-four adult male Swiss mice weighing 20-25 g were divided into 4 groups: group C (N = 6) was not subjected to any surgical manipulation; group SH (N = 6) was subjected to surgical manipulation but without ureter ligation; group UUO (N = 6) was subjected to unilateral ureteral obstruction and received no treatment; group UUO plus DS (N = 6) was subjected to UUO and received DS (4 mg/kg) subcutaneously daily for 14 days. An immunoblot study was also performed for TGF-β. Collagen (stained area ~3700 µm²), MCP-1 (stained area ~1700 µm²), TGF-β (stained area ~13 percent of total area), macrophage (number of cells ~40), and myofibroblast (stained area ~1900 µm²) levels were significantly (P < 0.05) higher in the UUO group compared to control. DS treatment significantly (P < 0.05) reduced the content of collagen (stained area ~700 µm²), MCP-1 (stained area ~160 µm²) and TGF-β (stained area ~5 percent of total area), in addition to myofibroblast (stained area ~190 µm²) and macrophage (number of cells ~32) accumulation in the obstructed kidney. Overall, these results indicate that DS attenuates kidney inflammation by reducing macrophage recruitment, myofibroblast population and fibrosis in mice submitted to UUO.
Assuntos
Animais , Masculino , Camundongos , Anti-Inflamatórios/farmacologia , /metabolismo , Dermatan Sulfato/farmacologia , Macrófagos/efeitos dos fármacos , Miofibroblastos/efeitos dos fármacos , Fator de Crescimento Transformador beta/biossíntese , Obstrução Ureteral/complicações , Anti-Inflamatórios/administração & dosagem , Modelos Animais de Doenças , Dermatan Sulfato/administração & dosagem , Fibrose , Injeções Subcutâneas , Rim/patologia , Ativação de Macrófagos , Macrófagos/metabolismo , Miofibroblastos/metabolismo , Nefrite/prevenção & controle , Obstrução Ureteral/patologiaRESUMO
In the ascidian Styela plicata, the oocytes are surrounded by two types of accessory cells named follicle cells and test cells. A heparin-like substance with an anticoagulant activity equivalent to 10% of mammalian heparin and about 5% as potent as the mammalian counterpart for the inhibition of thrombin by antithrombin was isolated from the oocyte test cells. In the present study, we compared the antithrombotic and hemorrhagic effects of sea squirt oocyte test cell heparin with those of porcine heparin in rat models of venous thrombosis and blood loss. Intravenous administration of the oocyte test cell heparin to Wistar rats (both sexes, weighing approximately 300 g, N = 4 in each group) at a dose of 5.0 mg/kg body weight, which produced a 1.8-fold increase in plasma activated partial thromboplastin time, inhibited thrombosis by 45 +/- 13.5% (mean +/- SD) without any bleeding effect. The same dose of porcine heparin inhibited thrombosis by 100 +/- 1.4%, but produced a blood loss three times greater than that of the saline-treated control. However, 10-fold reduction of the dose of porcine heparin to 0.5 mg/kg body weight, which produced a 5-fold increase in plasma-activated partial thromboplastin time, inhibited thrombosis by 70 +/- 13% without any bleeding effect. The antithrombotic properties of a new heparin isolated from test cells of the sea squirt S. plicata, reported here for the first time, indicate that, although sea squirt oocyte test cell heparin was a poor anticoagulant compared to porcine heparin, it had a significant antithrombotic effect without causing bleeding.
Assuntos
Anticoagulantes/isolamento & purificação , Antitrombinas/isolamento & purificação , Heparina/isolamento & purificação , Oócitos/química , Urocordados/química , Trombose Venosa/prevenção & controle , Animais , Anticoagulantes/uso terapêutico , Antitrombinas/uso terapêutico , Modelos Animais de Doenças , Inibidores do Fator Xa , Feminino , Hemorragia/tratamento farmacológico , Heparina/uso terapêutico , Masculino , Tempo de Tromboplastina Parcial , Ratos , Ratos Wistar , Suínos , Urocordados/citologiaRESUMO
In the ascidian Styela plicata, the oocytes are surrounded by two types of accessory cells named follicle cells and test cells. A heparin-like substance with an anticoagulant activity equivalent to 10 percent of mammalian heparin and about 5 percent as potent as the mammalian counterpart for the inhibition of thrombin by antithrombin was isolated from the oocyte test cells. In the present study, we compared the antithrombotic and hemorrhagic effects of sea squirt oocyte test cell heparin with those of porcine heparin in rat models of venous thrombosis and blood loss. Intravenous administration of the oocyte test cell heparin to Wistar rats (both sexes, weighing ~300 g, N = 4 in each group) at a dose of 5.0 mg/kg body weight, which produced a 1.8-fold increase in plasma activated partial thromboplastin time, inhibited thrombosis by 45 ± 13.5 percent (mean ± SD) without any bleeding effect. The same dose of porcine heparin inhibited thrombosis by 100 ± 1.4 percent, but produced a blood loss three times greater than that of the saline-treated control. However, 10-fold reduction of the dose of porcine heparin to 0.5 mg/kg body weight, which produced a 5-fold increase in plasma-activated partial thromboplastin time, inhibited thrombosis by 70 ± 13 percent without any bleeding effect. The antithrombotic properties of a new heparin isolated from test cells of the sea squirt S. plicata, reported here for the first time, indicate that, although sea squirt oocyte test cell heparin was a poor anticoagulant compared to porcine heparin, it had a significant antithrombotic effect without causing bleeding.
Assuntos
Animais , Masculino , Feminino , Ratos , Anticoagulantes/isolamento & purificação , Antitrombinas/isolamento & purificação , Heparina/isolamento & purificação , Oócitos/química , Urocordados/química , Trombose Venosa/prevenção & controle , Anticoagulantes/uso terapêutico , Antitrombinas/uso terapêutico , Modelos Animais de Doenças , Fator Xa/antagonistas & inibidores , Hemorragia/tratamento farmacológico , Heparina/uso terapêutico , Tempo de Tromboplastina Parcial , Ratos Wistar , Suínos , Urocordados/citologiaRESUMO
We compared the anticoagulant, antithrombotic and bleeding effects of highly sulfated dermatan sulfates from invertebrates and their mammalian counterpart. An invertebrate dermatan sulfate containing 2-O-sulfated alpha-L-iduronic acid and 4-O-sulfated N-acetyl-beta-D-galactosamine residues is a potent anticoagulant due to a high heparin cofactor II activity. It inhibits thrombin due to the formation of a covalent complex with heparin cofactor II, as in the case of mammalian dermatan sulfate, but the effect occurs at lower concentrations for the invertebrate polysaccharide. Surprisingly, the invertebrate dermatan sulfate has a lower potency to prevent thrombus formation on an experimental model and a lower bleeding effect in rats than the mammalian dermatan sulfate. In contrast, another invertebrate dermatan sulfate, also enriched in 2-O-sulfated alpha-L-iduronic acid, but in this case sulfated at O-6 position of the N-acetyl-beta-D-galactosamine units, has no in vitro or in vivo anticoagulant activity, does not prevent thrombus formation but shows a bleeding effect similar to the mammalian glycosaminoglycan. Overall, these results demonstrate unbalanced effects of dermatan sulfates with different sulfation patterns on coagulation, thrombosis and bleeding, and raise interesting questions concerning the relationship among these three biological actions of sulfated polysaccharides.
Assuntos
Anticoagulantes/farmacologia , Coagulação Sanguínea/efeitos dos fármacos , Dermatan Sulfato/farmacologia , Hemorragia/induzido quimicamente , Trombose/tratamento farmacológico , Animais , Anticoagulantes/administração & dosagem , Anticoagulantes/química , Bovinos , Dermatan Sulfato/administração & dosagem , Dermatan Sulfato/química , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Interações Medicamentosas , Feminino , Cofator II da Heparina/metabolismo , Masculino , Ligação Proteica/efeitos dos fármacos , Ratos , Ratos Wistar , Especificidade da Espécie , Trombina/antagonistas & inibidores , Trombina/metabolismo , Trombose/prevenção & controle , UrocordadosRESUMO
Several sulfated polysaccharides have been isolated from the test cells of the ascidian Styela plicata. The preponderant polysaccharide is a highly sulfated heparan sulfate with the following disaccharide composition: (1) UA(2SO4)-1-->4 GlcN(SO4)(6SO4), 53%; (2) UA(2SO4)-1-->4-GlcN(SO4), 22%; (3) UA-1-->4-GlcNAc(6SO4), 14% and (4) UA-1-->4-GlcN(SO4), 11%. Two others unidentified sulfated polysaccharides and a glycogen polymer are also present in the ascidian eggs. Histochemistry with the cationic dye 1,9-dimethyl-methylene blue and biochemical analysis of the 35S-sulfate incorporation into the eggs reveal that the sulfated glycans are present exclusively in the test cells. Possibly these sulfated polysaccharides are involved in important functions of these cells, such as to confer an external and hydrophilic layer which protect the eggs and the larvae of ascidians.
Assuntos
Heparitina Sulfato/isolamento & purificação , Óvulo/química , Urocordados/química , Animais , Células Cultivadas , Cromatografia em Gel , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Ágar , Eletroforese em Gel de Poliacrilamida , Glicogênio/análise , Heparitina Sulfato/química , Histocitoquímica , Liases , Radioisótopos de EnxofreRESUMO
Dermatan sulfates with the same backbone structure [4-alpha-L-IdceA-1-->3-beta-D-GalNAc-1]n but with different patterns of sulfation substitutions have been isolated from the ascidian body. All the ascidian dermatan sulfates have a high content of 2-O-sulfated alpha-L-iduronic acid residues but differ in the pattern of sulfation of the N-acetyl-beta-D-galactosamine units. Styela plicata and Halocynthia pyriformis have 4-O-sulfated units, but in Ascidian nigra they are 6-O-sulfated. This collection of ascidian dermatan sulfates (together with native and oversulfated mammalian dermatan sulfate), where the extent and position of sulfate substitution have been fully characterized, were tested in anticoagulant assays. Dermatan sulfate from A. nigra has no discernible anticoagulant activity, which indicates that 4-O-sulfation of the N-acetyl-beta-D-galactosamine is essential for the anticoagulant activity of this glycosaminoglycan. In contrast dermatan sulfates from S. plicata and H. pyriformis are potent anticoagulants due to potentiation of thrombin inhibition by heparin cofactor II. These ascidian dermatan sulfates have approximately 10-fold and approximately 6-fold higher activity with heparin cofactor II than native and an oversulfated mammalian dermatan sulfate, respectively. They have no effect on thrombin or factor Xa inhibition by antithrombin. These naturally oversulfated ascidian dermatan sulfates are sulfated at selected sites required for interaction with heparin cofactor II and thus have specific and potent anticoagulant activity.
Assuntos
Anticoagulantes/isolamento & purificação , Dermatan Sulfato/isolamento & purificação , Ésteres do Ácido Sulfúrico/isolamento & purificação , Urocordados/química , Acetilgalactosamina/análogos & derivados , Animais , Ânions , Antitrombinas/farmacologia , Dissacarídeos/análise , Fator Xa/metabolismo , Cofator II da Heparina , Ácido Idurônico/análogos & derivados , Ressonância Magnética Nuclear Biomolecular , Tempo de Tromboplastina Parcial , Especificidade da Espécie , Trombina/metabolismoRESUMO
A dermatan sulfate-like glycosaminoglycan was isolated from the body of the ascidian Ascidia nigra (J. Biol. Chem. 270: 31027-31036, 1995). 1H NMR and fast atom bombardment mass spectrometry (FAB-MS) spectra of the tetra and disaccharides formed by chondroitin ABC lyase digestion support the proposed repeating disaccharide structure for this glycosaminoglycan, [-->4)-alpha-L-IdoA(2SO4)-(1-->3)-beta-D-GalNAc(6SO4)-(1-->] , which differ from mammalian dermatan sulfate in its sulfation at both 2-position of the alpha-L-iduronic acid and the 6-position of the N-acetyl-beta-D-galactosamine residue.
Assuntos
Condroitina Liases/metabolismo , Dermatan Sulfato/metabolismo , Urocordados/química , Acetilgalactosamina/química , Acetilgalactosamina/metabolismo , Animais , Dermatan Sulfato/química , Dermatan Sulfato/isolamento & purificação , Dissacarídeos/química , Dissacarídeos/metabolismo , Ácido Idurônico/química , Ácido Idurônico/metabolismo , Espectroscopia de Ressonância Magnética , Oligossacarídeos/química , Oligossacarídeos/metabolismo , Espectrometria de Massas de Bombardeamento Rápido de Átomos , Sulfatos/metabolismoRESUMO
A polysaccharide isolated from the body wall of the sea cucumber Ludwigothurea grisea has a backbone like that of mammalian chondroitin sulfate: [4-beta-D-GlcA-1-->3-beta-D-GalNAc-1]n but substituted at the 3-position of the beta--glucuronic acid residues with sulfated alpha--fucopyranosyl branches (Vieira, R. P., Mulloy, B., and Mourão, P. A. S. (1991) J. Biol. Chem. 266, 13530-13536). Mild acid hydrolysis removes the sulfated alpha--fucose branches, and cleaved residues have been characterized by 1H NMR spectroscopy; the most abundant species is fucose 4-O-monosulfate, but 2,4- and 3, 4-di-O-sulfated residues are also present. Degradation of the remaining polysaccharide with chondroitin ABC lyase shows that the sulfated alpha-L-fucose residues released by mild acid hydrolysis are concentrated toward the non-reducing end of the polysaccharide chains; enzyme-resistant polysaccharide material includes the reducing terminal and carries acid-resistant -fucose substitution. The sulfated alpha-L-fucose branches confer anticoagulant activity on the polysaccharide. The specific activity of fucosylated chondroitin sulfate in the activated partial thromboplastin time assay is greater than that of a linear homopolymeric alpha-L-fucan with about the same level of sulfation; this activity is lost on defucosylation or desulfation but not on carboxyl-reduction of the polymer. Assays with purified reagents show that the fucosylated chondroitin sulfate can potentiate the thrombin inhibition activity of both antithrombin and heparin cofactor II.
Assuntos
Anticoagulantes/química , Sulfatos de Condroitina/química , Pepinos-do-Mar/química , Animais , Antitrombina III/farmacologia , Sulfatos de Condroitina/farmacologia , Cromatografia em Camada Fina , Inibidores Enzimáticos/farmacologia , Fucose/química , Cofator II da Heparina/farmacologia , Humanos , Espectroscopia de Ressonância Magnética , Tempo de Tromboplastina Parcial , Relação Estrutura-Atividade , Trombina/antagonistas & inibidoresRESUMO
Unique sulfated polysaccharides have been identified in ascidian tissues. A high-molecular-weight sulfated L-galactan consisting mainly of alpha-L-galactopyranose glycosidically linked through positions 1-->4, and sulfated at carbon 3 is present in the tunic of all species studied. Methylation, periodate oxidation, as well as 1H and 13C NMR analysis revealed that despite their homogeneous chemical composition, these L-galactans differ in type of glycosidic linkage, number of branches, and in the extent and position of sulfation. These L-galactans are synthesized by epidermal cells that epimerize D-glucose, possibly from a trehalose precursor, into L-galactose. In addition, a dermatan sulfate composed of a backbone of repeating [4-alpha-L-IdoA-1-->3-beta-D-GalNAc-1]n units similar to mammalian dermatan sulfate, but differing in the extent and position of sulfation has been isolated from the body of the ascidian, Ascidia nigra. Degradation of the ascidian dermatan with specific glycosidases and sulfatases, together with 1H and 13C NMR data, indicated that the disaccharide units are sulfated at the 2-position of alpha-L-induronate residues and at the 6-position of the N-acetyl-beta-D-galactosamine units. In contrast to mammalian dermatan sulfate, the ascidian molecule has no discenrible anticoagulant activity, as measured by the APTT assay, and has a low ability to potentiate heparin cofactor II. These data suggest that the 4-O-sulfation of N-acetyl-beta-D-galactosamine residues is essential for the anticoagulant activity of dermatan sulfate polymers.
Assuntos
Galactanos/metabolismo , Urocordados/metabolismo , Animais , Galactanos/química , Glicosaminoglicanos/metabolismoRESUMO
A dermatan sulfate, similar to the mammalian glycosaminoglycans but not identical with any of them, has been isolated from the body of the ascidian Ascidia nigra. Degradation with chondroitin ABC lyase, analysis of the disaccharide products by digestion with chondro-4- and -6-sulfatases, and 1H and 13C NMR data confirm that the predominant structure is [4-alpha-L-IdoA-(2SO4)-1-->3-beta-D-GalNAc(6SO4)-1]n. Mammalian dermatan sulfate is an anticoagulant due to its ability to potentiate inhibition of thrombin by heparin cofactor II. The structure in dermatan sulfate which binds to heparin cofactor II is [4-alpha-L-IdoA-(2SO4)-1-->3-beta-D-GalNAc(4SO4)-1]n, where n > or = 3. We have compared the ascidian dermatan sulfate with mammalian dermatan sulfate and with chemically oversulfated mammalian dermatan sulfate for anticoagulant activity as measured by the activated partial thromboplastin time assay and for its ability to potentiate heparin cofactor II. In spite of its high content of 2-O-sulfated alpha-L-iduronic acid residues, the ascidian compound had no discernible anticoagulant activity and had low ability to potentiate heparin cofactor II. These results suggest that 4-O-sulfation of the N-acetyl-beta-D-galactosamine residues is essential for the anticoagulant activity of dermatan sulfate.
Assuntos
Anticoagulantes/química , Dermatan Sulfato/química , Sulfatos/química , Acetilgalactosamina/química , Animais , Anticoagulantes/isolamento & purificação , Anticoagulantes/farmacologia , Sequência de Carboidratos , Condroitina Liases/metabolismo , Cromatografia DEAE-Celulose , Cromatografia em Papel , Dermatan Sulfato/isolamento & purificação , Dermatan Sulfato/farmacologia , Cofator II da Heparina/química , Humanos , Hidrólise , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , UrocordadosRESUMO
Histochemical and chemical analyses reveal important differences between tunic and body of the ascidian Styela plicata. The body contains hydroxyproline, nucleic acid and hexuronic acid. Analyses of the hexuronic acid-containing molecules indicates the presence of dermatan sulfate and heparan sulfate. The tunic, on the other hand, contains no hydroxyproline and small amounts of nucleic acid and hexuronic acid. Large amounts of sulfated polysaccharides, identified by agarose gel electrophoresis, are also present in the tunic. In vitro, incorporation of 35S-sulfate and 14C-glucose and 35S-sulfate pulse-chase experiments show that sulfate and glucose are incorporated into the sulfated polysaccharides of the tunic. The radioactivity is associated mainly with the region of the tunic containing the epidermal cells; however, a small amount of radioactivity is also detected in other regions of the tunic, suggesting that the sulfated polysaccharides are synthesized mainly by the epidermal cells and, to a small extent, by other cell types present in the tunic. Conversion of D-glucose to L-galactose, previously observed in the tunic of Styela plicata (Biochemistry 30, 3458-3464, 1990) is more intense in the region of the tunic containing the epidermal cells.
Assuntos
Galactanos/biossíntese , Urocordados/metabolismo , Animais , Sequência de Carboidratos , Radioisótopos de Carbono , Dermatan Sulfato/metabolismo , Glucose/metabolismo , Dados de Sequência Molecular , Polímeros/metabolismo , Sulfatos/metabolismo , Radioisótopos de EnxofreRESUMO
A purified sulfated alpha-L-galactofucan from Clavelina sp. has been studied before and after desulfation, using periodate oxidation, methylation analysis, and n.m.r. spectroscopy, and shown to be composed mainly of 3-sulfated 4-linked alpha-L-galactopyranosyl residues. There was also a small proportion of 3-sulfated 4-linked alpha-L-fucose residues.
Assuntos
Polissacarídeos/química , Urocordados/análise , Animais , Sequência de Carboidratos , Espectroscopia de Ressonância Magnética , Metilação , Dados de Sequência Molecular , Oxirredução , Ácido Periódico , Polissacarídeos/isolamento & purificação , Ácidos SulfúricosRESUMO
The tunic of the ascidian Styela plicata is rich in a high molecular weight sulfated-L-galactan called the F-1 fraction. This polysaccharide is of complex structure and is highly branched. In this study we undertook detailed structural analysis of the F-1 fraction that was submitted to the Smith degradation procedure which, for this polysaccharide, results mainly in the elimination of the branches. By methylation, and one- and two-dimensional n.m.r. analysis of the Smith-degraded and desulfated Smith-degraded F-1 fraction, we determined the main structure of this polymer. It is composed of a core of alpha-L-galactopyranose units, sulfated at C-3 and glycosidically linked through position 1----4. The nonsulfated, nonreducing end units are branched at C-2 of the sulfated L-galactoses.
Assuntos
Galactanos/química , Urocordados/análise , Álcoois/síntese química , Animais , Sequência de Carboidratos , Cromatografia de Afinidade , Cromatografia DEAE-Celulose , Eletroforese em Gel de Ágar , Eletroforese em Gel de Poliacrilamida , Espectroscopia de Ressonância Magnética/métodos , Metilação , Dados de Sequência Molecular , Oxirredução , Ácido Periódico , Ácidos SulfúricosRESUMO
The sulfated polysaccharides that occur in the tunic of ascidians differ markedly in molecular weight and chemical composition. A high molecular weight fraction (F-1), which has a high galactose content and a strong negative optical rotation, is present in all species. Several structural differences were observed among the F-1 fractions obtained from three species of ascidians that were studied in detail. Large numbers of alpha-L-galactopyranose residues sulfated at position 3 and linked glycosidically through position 1----4 are present in F-1 from all three ascidians. However, alpha-L-galactopyranose units, 1----3-linked and partially sulfated at position 4, comprise about half of the sugar units in the central core of F-1 from Ascidian nigra. In addition, L-galactopyranose nonreducing end units occur in F-1 from Styela plicata and A. nigra, but comprise only a minor fraction of F-1 from Clavelina sp. The combination of these various component units gives a complex structure for F-1 from S. plicata and A. nigra, whereas F-1 from Clavelina sp. possesses a simpler structure. The structures of these ascidian glycans are unique among all previously described sulfated polysaccharides, since they are highly branched (except that from Clavelina sp), sulfated at position 3, and contain large amounts of L-galactose without its D-enantiomorph. These data show unusual examples of polyanionic glycans with structural function in animal tissues.