The effect of synthetic lipid A analogs on murine spleen cells was studied. The preparations represented D-glucosamine and D-glucosaminyl-beta 1,6-D-glucosamine disaccharide derivatives substituted in different combinations by ester- and amide-bound fatty acids and by phosphate groups. Significant mitogenic activity was demonstrated with a number of synthetic disaccharide preparations; however,...

Chronic exposure (48 h) to glucosamine resulted in a dose-dependent reduction of basal and insulin-stimulated glucose uptake activities in human skeletal muscle cell cultures from nondiabetic and type 2 diabetic subjects. Insulin responsiveness of uptake was also reduced. There was no change in total membrane expression of either GLUT1, GLUT3, or GLUT4 proteins. While glucosamine treatment had ...

1. The influence of insulin on the metabolism of [1-(14)C]glucosamine by diaphragm muscle from normal rats and rats rendered diabetic with streptozotocin has been studied. 2. The glucosamine was converted into glucosamine 1-phosphate, glucosamine 6-phosphate, glycogen, lactate and small amounts of other unidentified intermediates. 3. Insulin increased the incorporation of (14)C into glycogen in...

To study molecular mechanisms for glucosamine-induced insulin resistance, we induced complete and reversible insulin resistance in 3T3-L1 adipocytes with glucosamine in a dose- and time-dependent manner (maximal effects at 50 mM glucosamine after 6 h). In these cells, glucosamine impaired insulin-stimulated GLUT-4 translocation. Glucosamine (6 h) did not affect insulin-stimulated tyrosine phosp...

Background & Objective. Osteoarthritis is progressive degenerative disease resulting in significant affection of joints. Nonsteroidal anti-inflammatory drugs (NSAIDS) are widely used in this condition but are associated with significant side effects; hence the aim of this study was to evaluate the efficacy and tolerability of nutritional supplements such as Glucosamine, Chondroitin sulphate and...

The metabolism of the glycation product fructose-epsilon-lysine in Escherichia coli involves its ATP-dependent phosphorylation by a specific kinase (FrlD), followed by the conversion of fructoselysine 6-phosphate into glucose 6-phosphate and lysine by fructoselysine-6-phosphate deglycase (FrlB), which is distantly related to the isomerase domain of glucosamine-6-phosphate synthase. As shown in ...

Two deoxyglucose (DG) derivatives, (α,β)-2-deoxy-2-amino(ethylcarbamate)-D-glucose (ECB-DG) and (α,β)-2-deoxy-2-amino(1,2-dihydroxypropyl)-D-glucose (DHP-DG), were synthesized and radiolabeled successfully with [99mTc(H2O)3(CO)3]+ complex. [99mTc]-ECB-DG and [99mTc]-DHP-DG complexes were prepared (96% and 93% radiochemical purities respectively) by using 46 mCi of Na99mTcO4 in 1 mL saline. Radi...

Little is known about the biosynthesis of glucosamine in mammalian organisms. Previous studies have indicated the presence of enzymes in several mammalian tissues capable of synthesizing glucosamine (1, 2). Moreover, there is evidence that glucose, without scission of its carbon chain, may serve as the precursor of glucosamine in the intact animal (3, 4), as in bacteria (5, 6). However, except ...

OBJECTIVE Glucosamine is widely used to improve the symptoms and to delay the structural progression of osteoarthritis. However, its efficacy in osteoarthritis has been controversial and its underlying mechanism of action remains unclear. The aim of this study was to investigate the effects of glucosamine and the underlying mechanisms in human chondrocytes. METHODS Chondrocytes from normal hu...

Being naturally derived from the cellular glucose metabolism, glucosamine is present in the hyaluronic acid present in the synovial fluid and also the fluids that help in lubrication of the cartilage in the joint cavities. This monomer, derived from the shell-fish waste or shell-fish chitosan by hydrolysis, it is widely accepted as a dietary supplement by FDA with its increasing commercial pote...