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Results for “GLUCOSAMINE”

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PubMed2003

A randomized, double blind, placebo controlled trial of a topical cream containing glucosamine sulfate, chondroitin sulfate, and camphor for osteoarthritis of the knee.

OBJECTIVE: To assess the ability of a topical preparation of glucosamine sulfate and chondroitin sulfate to reduce pain related to osteoarthritis (OA) of the knee. METHODS: Sixty-three patients were randomized to receive either a topical glucosamine and chondroitin preparation or placebo to be used as required over an 8 week period. Efficacy was assessed using a visual analog scale (VAS) for pain as well as the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the SF-36 questionnaire. RESULTS: VAS scores indicated a greater mean reduction in pain for the glucosamine/chondroitin preparation group (mean change -3.4 cm, SD 2.6 cm) compared to the placebo group (mean change -1.6 cm, SD 2.7 cm) after 8 weeks. After 4 weeks the difference between active and placebo groups in their mean reduction from baseline was 1.2 (95% CI 0.1 to 2.4, p = 0.03) and after 8 weeks was 1.8 (95% CI for difference between groups, 0.6 to 2.9 cm; p = 0.002). CONCLUSION: Topical application of glucosamine and chondroitin sulfate is effective in relieving the pain from OA of the knee and improvement is evident within 4 weeks.

Administration, Topical↗

PubMed1992

UDP-N-acetylhexosamine modulation by glucosamine and uridine in NCI N-417 variant small cell lung cancer cells: 31P nuclear magnetic resonance results.

Small cell lung cancer (SCLC) occurs as two neuroendocrine subtypes, SCLC-C (classic) and SCLC-V (variant). One reported difference is elevated levels of diphosphodiesters (DPDE) in the more differentiated SCLC-C subtype. DPDE have been identified as primarily UDP-N-acetylhexosamines (UDP-NAH) in a variety of tumors, and changes in DPDE levels have been observed during experiments designed to induce cell differentiation. UDP-NAH synthesis is controlled by negative feedback regulation of glutamine:fructose-6-P amidotransferase (EC 2.6.1.16), which can be circumvented by glucosamine. Using 31P nuclear magnetic resonance analysis of extracts and perfused cells, we have identified UDP-N-acetylglucosamine and UDP-N-acetylgalactosamine as the primary metabolites in the DPDE spectral region of SCLC-V N-417 cells. Glucosamine addition causes a rapid increase in UDP-NAH levels. At glucosamine: glucose ratios of 1:1 and 10:1 formation of the UDP-NAH intermediates N-acetylglucosamine 6-phosphate and UDP-N-acetylglucosamine 1-phosphate is also observed, indicating UTP limitation. Subsequent uridine addition results in depletion of the intermediates and increased UDP-NAH formation. Moreover, N-417 cells retain the capacity to rapidly convert uridine to UTP despite low ATP and phosphocreatine levels. This expansion of the uridine pool may represent an additional metabolic reserve not yet addressed in the design of therapy options.

Carcinoma, Small Cell↗

PubMed2003

[Study on the role of glucosamine hydrochloride in the pathogenesis of osteoarthritis].

The role of glucosamine hydrochloride in the pathogenesis of osteoarthritis in animal models of sponge granuloma, Kaolin arthritiaand and adjuant arthritis was studied. The results showed that glucosamine hydrochloride inhibited granulation, delayed immunoreactivity, immunological-reative arthritis in daily doses of 0.25-0.75 g/kg BW orally and vascular oozing, tissue swelling and cell isolating in daily doses of 0.5-1.5 g/kg BW orally, indicating that glucosamine hydrochloride might have a preventive and theraputic effect on osteoarthritis.

Animals↗

PubMed2006

Glucosamine-induced endoplasmic reticulum dysfunction is associated with accelerated atherosclerosis in a hyperglycemic mouse model.

Diabetes is a major independent risk factor for cardiovascular disease and stroke; however, the molecular and cellular mechanisms by which diabetes contributes to the development of vascular disease are not fully understood. Our previous studies demonstrated that endoplasmic reticulum (ER) stress-inducing agents, including homocysteine, promote lipid accumulation and activate inflammatory pathways-the hallmark features of atherosclerosis. We hypothesize that the accumulation of intracellular glucosamine observed in diabetes may also promote atherogenesis via a mechanism that involves ER stress. In support of this theory, we demonstrate that glucosamine can induce ER stress in cell types relevant to the development of atherosclerosis, including human aortic smooth muscle cells, monocytes, and hepatocytes. Furthermore, we show that glucosamine-induced ER stress dysregulates lipid metabolism, leading to the accumulation of cholesterol in cultured cells. To examine the relevance of the ER stress pathway in vivo, we used a streptozotocin-induced hyperglycemic apolipoprotein E-deficient mouse model of atherosclerosis. Using molecular biological and histological techniques, we show that hyperglycemia is associated with tissue-specific ER stress, hepatic steatosis, and accelerated atherosclerosis. This novel mechanism may not only explain how diabetes and hyperglycemia promote atherosclerosis, but also provide a potential new target for therapeutic intervention.

Animals↗

PubMed1991

Direct evidence of the Entner-Doudoroff pathway operating in the metabolism of D-glucosamine in bacteria.

Pseudomonas fluorescens (Migula) (IFO 14808) has both a membrane-bound PQQ-dependent D-glucose (D-Glc) dehydrogenase [EC 1.1.99.17] [which also acts on D-glucosamine (D-GlcN)] and a PLP-dependent D-glucosaminate (D-GlcNA) dehydratase [EC 4.2.1.26]. Further, these two enzymes were induced when D-GlcN was added to the culture medium. However, D-glucosamine-6-phosphate (D-GlcN-6-P) isomerase [EC 5.3.1.10], another enzyme involved in the metabolism of D-GlcN, was only present at a low level in this bacterium. The bacterium was able to grow in a minimal medium containing D-GlcN or D-GlcNA as the sole source of carbon and nitrogen. Intact cells of P. fluorescens (Migula) converted D-GlcN to D-GlcNA and then to 2-keto-3-deoxy-D-gluconate (KDGA). These results demonstrate that D-GlcN is metabolized via D-GlcNA to KDGA in P. fluorescens (Migula) (Entner-Doudoroff pathway). In contrast, Enterobacter cloacae(IFO 13535) and Agrobacterium radiobacter (IAM 1526) have significant amounts of D-GlcN-6-P isomerase with low levels of the D-Glc dehydrogenase and D-GlcNA dehydratase. Further, only the isomerase activity was induced on the addition of D-GlcN to the culture medium. These results demonstrate that there is a new route (Entner-Doudoroff pathway), i.e., in addition to the known one (Embden-Meyerhof pathway), for the metabolism of D-GlcN in bacteria and one of the two routes is predominant in the each of bacteria examined.

Aldose-Ketose Isomerases↗

PubMedDate not supplied

[Physiologic importance of glucosamine].

The paper reviews the present state of the problem on the physiological importance of D-(+)-glucosamine, an amino sugar. Glucosamine is shown to be a component of many biological important systems widely spread in nature. It is a part of the connective tissues, membranes, lipopolysaccharides and mucopolysaccharides and participates in detoxic function of the liver and kidneys. The data from literature reviewed permit concluding that glucosamine and its derivatives are potentially useful and possess antiinflammatory, liver-defending, antihypoxic and other pharmacological activities.

Adult↗

PubMedDate not supplied

[The liver-protective properties of D-glucosamine].

The antioxidant and membrane-stabilizing activities of D-glucosamine were studied on two models of toxic liver damage. When administered in a dose of 50 mg/kg, D-glucosamine was found to prevent the development of the hepatocyte cytolysis syndrome, to normalize the cholate- and glycogen-synthetic functions of the liver. D-glucosamine exhibited a significant anabolic effect that also supplemented its hepatoprotective activity.

Animals↗

PubMed1989

Localization of 3H-proline, 35S-sulfate and 3H-glucosamine in rat cornea following epithelial removal: epithelio-stromal interaction.

Localization of 3H-proline, 35S-sulfate and 3H-glucosamine was studied by autoradiography in the rat cornea following the removal of the epithelium. The three labeling chemicals were injected into the anterior chamber of rats, one chemical in each rat, 24 hours after the removal of the epithelium. Animals were sacrificed at various intervals up to 7 days after the injection. The silver grains of 35S-sulfate incorporated into the re-covered epithelium gradually shifted into the stroma. On the other hand, the 3H-glucosamine tended to move toward the epithelial cell membrane and the superficial layer of the epithelium. The 3H-proline incorporated in the epithelium remained in the cells without movement. These results suggest that the 35S-sulfate in the epithelium shifted into the stroma as 35S-phosphoadenosine-phosphosulfate [35S-PAPS] before sulfation of glycoconjugates occurred in the epithelium. A large amount of 3H-glucosamine was utilized as a component of low-sulfated glycoconjugates in the epithelial cell membrane and other cell-coating substances.

Adenine Nucleotides↗

PubMed1979

3H-glucosamine electron microscope autoradiography after isolated labeling of the enamel organ or the dental papilla followed by reassociated toothgerm culture.

Electron microscope autoradiography was performed after isolated labeling with 3H-glucosamine of the enamel organ or the dental papilla of Swiss mice followed by reassociated toothgerm culture for 9.30 h and 19 h. After these two time intervals in case of an enamel organ labeling, numerous silver grains were observed in the intercellular spaces of the stellate reticulum indicating a concentrating and storing role of the latter. After dental papilla labeling, an almost complete absence of radioactivity was noted at 19 h. suggesting that 3H-glucosamine is not stored by the dental papilla. A clear labeling of the basement membrane area and of the adjacent aperiodic filamentous material found on the pulpal side was only observed after enamel organ labeling with 3H-glucosamine, suggesting an epithelial origin of the glycosaminoglycans found in these structures.

Animals↗

PubMed1987

[Conjugates of amino acids with glucosamine isolated from the plasma of rats with Guerin carcinoma].

The conjugate of amino acids and glucosamine (glycamine) was purified to homogeneity from blood plasma of rats with Guerin carcinoma. The NH2-groups of amino acids in the glycamine are free. Amino acids are linked to glucosamine via carboxyl groups. 8 amino acids residues were identified in the glycamine molecule (Glu-2, Ser-2, Gly-3, Lys-1). Spatial atomic-molecular model of the glycamine molecule was developed. Two glucosamine molecules are linked to diaminosaccharide via (1-4)-bond, 8 amino acid molecules are linked to diaminosaccharide via 6 ester and 2 pseudopeptide bonds.

Amino Acids↗

PubMed1979

Enhanced uptake of 3H-glucosamine by macrophages stimulated by macrophage-activating factor.

The enhanced uptake and incorporation of 3H-glucosamine by guinea pig peritoneal exudate macrophages stimulated by macrophage-activating factor (MAF) were studied. MAF was produced by concanavalin A- (Con A) stimulated lymphocytes. Two systems were developed to assay this phenomenon, one using microtiter plates, the other using suspension cultures. Enhanced uptake of 3H-glucosamine by macrophages was found after 48-hr incubation in microtiter plates and after 24 hr in suspension cultures. Increased uptake of 14C-glucose and 3H-galactose was also observed under these conditions. The enhanced uptake of 3H-glucosamine was markedly reduced or abolished by the addition of glucose to the cell cultures or by replacement of the medium with fresh medium before pulsing with labeled sugar. These observations indicate that the mechanism of enhanced uptake reflects in part increased glucose utilization by the stimulated macrophages.

Animals↗

PubMed1975

Biosynthesis of yeast mannan. Isolation of Kluyveromyces lactis mannan mutants and a study of the incorporation of N-acetyl-D-glucosamine into the polysaccharide side chains.

One side chain in the cell wall mannan of the yeast Kluyveromyces lactis has the structure (see article). (Raschke, W. C., and Ballou, C. E. (1972) Biochemistry 11, 3807). This (Man)4GNAc unit (the N-acetyl-D-glucosamine derivative of mannotetroase) and the (Man)4 side chain, aMan(1 yields 3)aMan(1 yields 2)aMan(1 yields 2)Man, are the principle immunochemical determinants on the cell surface. Two classes of mutants were obtained which lack the N-acetyl-D-glucosamine-containing determinant. The mannan of one class, designated mmnl, lacks both the (Man)4GNAc and (Man)4 side chains. Apparently, it has a defective alpha-1 yields 3-mannosyltransferase and the (Man)4 unit must be formed to serve as the acceptor before the alpha-1 yields 2-N-acetyl-glucosamine transferase can act. The other mutant class, mnn2, lacks only the (Man)4GNAc determinant and must be defective in adding N-acetylglucosamine to the mannotetrasose side chains. Two members of this class were obtained, one which still showed a wild type N-acetylglucosamine transferase activity in cell-free extracts and the other lacking it. They are allelic or tightly linked, and were designated mnn2-1 mnn2-2. Protoplast particles from the wild type cells catalyzed a Mn2+-dependent transfer of N-acetylglucosamine from UDP-N-acetylglucosamine to the mannotetraose side chain of endogenous acceptors. Exogenous mannotetraose also served as an acceptor in a Mn2+-dependent reaction and yielded (Man)4GNAc. Related oligosaccharides with terminal alpha (1 yields 3)mannosyl units were also good acceptors. The product from the reaction with alphaMan(1 yields 3)Man had the N-acetylglucosamine attached to the mannose unit at the reducing end, which supports the conclusion that the cell-free glycosyltransferase activity is identical with that involved in mannan synthesis. The reaction was inhibited by uridine diphosphate. Protoplast particles from the mmnl mutants showed wild type N-acetylglucosamine transferase activity with exogenous acceptor, but they had no endogenous activity because the endogenous mannan lacked acceptor side chains. Particles from the mnn2-1 mutant failed to catalyze N-acetylglucosamine transfer. In contrast, particles from the mnn2-2 mutant were indistinguishable from wild type cells in their transferase activity. Some event accompanying cell breakage and assay of the mnn2-2 mutant allowed expression of a latent alpha-1 yields 2-N-acetylglucosamine transferase with kinetic properties similar to those of the wild type enzyme.

Acetylglucosamine↗

PubMed1979

Effect of inflammatory serum on 14C-glucosamine incorporation into bone marrow granulocytes in vitro.

As a preliminary approach to developing a biochemical assay for detecting humoral regulators of granulocyte maturation in the normal and inflammatory states, studies were carried out on the effects of normal and inflammatory sera on the incorporation of 14C-glucosamine into the glycoproteins of bone marrow granulocytes in vitro. We observed that, relative to normal serum, inflammatory serum had a marked stimulatory effect on 14C-glucosamine incorporation into these glycoproteins. This property of inflammatory serum reached a maximum at about 8 h after the initiation of inflammation in vivo and preceded the maximum increase in the mitotic activity of granulocyte precursors in the marrow by 18 h. It was also found that normal serum contains both dialyzable and heat-sensitive nondialyzable factors that inhibit 14C-glucosamine incorporation into bone marrow granulocytes in vitro. Data are presented which indicate that the stimulatory effect of inflammatory serum is most likely due to a nondialyzable factor which is capable of blocking the effect of the inhibitors present in normal serum.

Animals↗

PubMed1979

Effect of 2-deoxy-D-glucose and glucosamine on bovine respiratory syncytial virus.

2-Deoxy-D-glucose (2-dG) and glucosamine reversibly inhibited the replication and cytopathic effects of bovine respiratory syncytial virus in bovine turbinate cell cultures. The inhibitors were effective when added up to 12 hours after cell cultures were inoculated. Their effectiveness decreased as the time between inoculation of cells and drug treatment lengthened. The sugars did not inactivate the virus directly, and inoculation of drug-treated cells in drug-free medium produced normal yield of virus. Mannose fully reversed the inhibitory effects of 2-dG, but was ineffective for glucosamine. Protein synthesis was necessary for production and release of infective virus after removal of 2-dG and glucosamine blocks. Electron microscopic studies revealed a large amount of bovine respiratory syncytial virus production with characteristic spike-like projections on the viral envelopes in the absence of these inhibitors. There was a drastic reduction in the number of mature virions produced in inhibitor-treated bovine turbinate cells, and the virions lacked the characteristic surface projections.

Animals↗

PubMed1977

[Physiology and biochemistry of streptomycetes. XIII. Biosynthesis of paromomycin by Streptomyces albus var. metamycinus nov. var. supplied with 14C-glucose, 14C-glucosamine, 14C-2-desoxystreptamine and 14C-ribose].

Distribution of radioactivity in paromomycin ascertained after application of 14C-D-glucose, 14C-D-glucosamine, 14C-2-deoxystreptamine, respectively, 14C-D-ribose is taken as basis for a biosynthesis scheme: While ribose bound in the antibiotic originates from glucose by oxidation and following decarboxylation, glucosamine is formed via fructose-6-phosphate. Paromose I arises from glucosamine, but not the cyclohexan derivative 2-deoxystreptamine, whose biosynthesis pathway is directly branching off glucose.

Carbon Radioisotopes↗

PubMed1984

The induction of enhanced glucosamine incorporation into the cell-envelope of Escherichia coli K-12 by the antibiotic tetaine.

The dipeptide antibiotic tetaine and its C-terminal aminoacid-anticapsin are powerfull inhibitors of glucosamine-synthetase EC 5.3.1.19 activity in cell-free extract from Escherichia coli K-12. Tetaine strongly inhibits the incorporation of diaminopimelic acid into the peptidoglycan of bacteria. In media with carbon source other than glucose tetaine induced of enhanced glucosamine incorporation into the cell-envelope of Escherichia coli K-12. Compounds from cell-envelope with enhanced labeled glucosamine contents are solubilisable by pronase treatment.

Anti-Bacterial Agents↗

PubMed1984

Absorption, distribution and excretion of radioactivity after a single intravenous or oral administration of [14C] glucosamine to the rat.

Blood levels, tissue distribution and excretion patterns of radioactivity were studied in the rat after administration of [14C] glucosamine sulphate by the intravenous or oral route. After intravenous administration, plasma radioactivity declined in the first 30 min, then increased, reaching a peak at the 2nd hour, and disappeared, with a half-disappearance time of 28 hours. The radioactivity diffused rapidly in the tissues. Higher levels than in plasma were reached in the liver and kidneys. There was early incorporation of radioactivity in the skeletal tissues (cartilage and bone). About 50% of the administered radioactivity was excreted with the expired CO2 and about 35% with the urine. Faecal excretion was small (2% of the administered dose). After oral administration, radioactivity was quickly found in plasma, where it reached a peak at 4 hours. It then declined slowly, with biphasic kinetics. The tissue distribution, including uptake in the skeleton, repeated the pattern found after intravenous administration. There was only small faecal excretion, showing an almost complete bioavailability of glucosamine given orally, and the large excretion with the CO2 (82%) showed that glucosamine is to a large extent broken down to smaller fragments. Autoradiographic studies confirmed the tissue distribution pattern and showed in more detail the tissue localization of radioactivity.

Administration, Oral↗

PubMed1980

[Glucosamine: its value for the metabolism of articular cartilage. 1. Biochemistry of proteoglycans, studies on in-vitro cultures of embryonal mouse fibroblasts and bone germs].

Mucopolysaccharides (glycosaminoglycanes) are essential constituents of the cartilage (chondroitin sulfate) and the synovial fluid (hyaluronic acid). They are formed within the chondrocyte preferably from glucosamine or from glucose and bound to protein constituting proteoglycanes. Non steroidal anti-inflammatory drugs and corticosteroids inhibit this synthesis. Primary fibroblast cultures and in vitro cultured mouse embryo tibiae show a dose-dependent increased synthesis of mucopolysaccharides and an enhanced growth of the bones after addition of glucosamine to the culture medium. This finding underlines the importance of a sufficient supply of the joints with glucosamine.

Adrenal Cortex Hormones↗