ABSTRACT
INTRODUCTION: In this study we examined oxidative stress and skeletal muscle damage resulting from acute strength, aerobic, or concurrent exercise in rats. METHODS: The animals were divided into control (C), strength (SE), aerobic (AE), and combined (CE) exercise groups. They were euthanized at 3 different time-points (6, 24, and 48 h) after acute exercise. RESULTS: SE exercise rats had increased dichlorofluorescein oxidation at 6 h post-exercise and decreased superoxide dismutase activity at all time-points. Glutathione peroxidase activity and sulfhydryl levels were increased in the AE group at 48 h post-exercise. Serum lactate dehydrogenase activity was increased in the SE and CE groups at 24 h and in the AE group at 48 h. Echo intensity was elevated at 24 h for all groups. CONCLUSIONS: Forty-eight hours was sufficient for complete recovery from oxidative stress and muscle damage in the SE and CE groups, but not in the AE group.
Subject(s)
Muscle Strength/physiology , Muscle, Skeletal/injuries , Physical Conditioning, Animal/physiology , Aerobiosis , Animals , Catalase/metabolism , Fluoresceins , Fluorescent Dyes , Glutathione Peroxidase/metabolism , L-Lactate Dehydrogenase/metabolism , Male , Muscle, Skeletal/diagnostic imaging , Oxidation-Reduction , Oxidative Stress/physiology , Rats , Rats, Wistar , Resistance Training , Sulfhydryl Compounds/metabolism , Superoxide Dismutase/metabolism , UltrasonographyABSTRACT
Lectin II from the marine sponge Axinella corrugata (ACL-II) was purified by affinity chromatography on rabbit erythrocytic stroma incorporated into a polyacrylamide gel, followed by gel filtration on Ultrogel AcA 44 column. Purified ACL-II is a lectin with an Mr of 80 kDa and 78 kDa, estimated by SDS-PAGE and by FPLC on Superose 12 HR column, respectively. ACL-II mainly agglutinates native rabbit erythrocytes and this hemagglutinating activity is independent of Ca(2+), Mg(2+) and Mn(2+), but is inhibited by d-galactose, chitin and N-acetyl derivatives, with the exception of GalNAc. ACL-II is stable for up to 65 °C for 30 min, with a better stability at a pH range of 2 to 6. In contrast, ACL-I displays a strong mitogenic and cytotoxic effect.
Subject(s)
Axinella/chemistry , Lectins/metabolism , Analysis of Variance , Animals , Chromatography, Affinity , Chromatography, Gel , Electrophoresis, Polyacrylamide Gel , Erythrocytes/drug effects , Hemagglutination Tests , Humans , Hydrogen-Ion Concentration , Lectins/isolation & purification , Lectins/pharmacology , Rabbits , Rosaniline Dyes , Time FactorsABSTRACT
The lectin from the marine sponge Axinella corrugata (ACL-I) was purified by affinity chromatography on rabbit erythrocytic stroma incorporated into a polyacrylamide gel followed by gel filtration on Ultrogel AcA 44 column. Purified ACL-I is a hexameric glycoprotein with a Mr of 82.3 kDa estimated by SDS-PAGE and 78.5 kDa by FPLC on Superose 12 HR column. The pI of lectin is 6.3 and ACL-I is constituted of 13.9 kDa similar subunits some of them linked by disulphide bridges. This lectin agglutinates native rabbit, goat and dog erythrocytes and in less extent human erythrocytes. The hemagglutinating activity is independent of Ca(2+), Mg(2+) and Mn(2+), but it is strongly inhibited by carbohydrates containing N-acetyl groups. ACL-I is stable up to 70 degrees C for 30 min, with optimum pH between 7 and 8, and it is also resistant to enzymatic proteolysis in vitro. In the presence of reducing or denaturant agents, the lectin activity decreases. ACL-I displays chemotactic effect on rat neutrophil in vitro which is inhibited by N-acetyl-d-glucosamine.
Subject(s)
Axinella/chemistry , Chemotactic Factors/isolation & purification , Hemagglutinins/isolation & purification , Lectins/isolation & purification , Animals , Chemotactic Factors/chemistry , Chemotactic Factors/pharmacology , Chemotaxis, Leukocyte , Chromatography, Affinity , Disulfides/isolation & purification , Dogs , Electrophoresis, Polyacrylamide Gel , Erythrocytes/drug effects , Goats , Hemagglutination , Hemagglutinins/chemistry , Hemagglutinins/pharmacology , Hot Temperature , Humans , Hydrogen-Ion Concentration , Isoelectric Point , Lectins/chemistry , Lectins/pharmacology , Male , Molecular Weight , Neutrophils/drug effects , Protein Denaturation , Protein Subunits , Rabbits , Rats , Rats, WistarABSTRACT
Glycans are key structures involved in biological processes such as cell attachment, migration, and invasion. Information coded on cell-surface glycans is frequently deciphered by proteins, as lectins, that recognize specific carbohydrate topology. Here, we describe the fine carbohydrate specificity of Euphorbia milii lectin (EML). Competitive assays using various sugars showed that GalNAc was the strongest inhibitor, and that the hydroxyl axial position of C4 and acetamido on C2 of GalNAc are critical points of EML recognition. A hydrophobic locus adjacent to GalNAc is also an important region for EML binding. Direct binding assays of EML revealed a stereochemical requirement for a structure adjacent to terminal GalNAc, showing that GalNAc residue is a necessary but not sufficient condition for EML interaction. The capacity of EML to bind epithelial tumor cells makes it a potentially useful tool for study of some over-expressed GalNAc glycoconjugates.
