O-GlcNAcylation augments vascular contractile responses, and O-GlcNAc-proteins are increased in the vasculature of deoxycorticosterone-acetate salt rats. Because endothelin 1 (ET-1) plays a major role in vascular dysfunction associated with salt-sensitive forms of hypertension, we hypothesized that ET-1–induced changes in vascular contractile responses are mediated by O-GlcNAc modification of p...

PURPOSE To investigate the protective effects of glucosamine (GlcN) using oxidative stress and rat models of ischemia-reperfusion (I/R) injury and to determine the antiapoptotic and anti-inflammatory mechanisms of GlcN treatment. METHODS We determined the effects of GlcN and the levels of O-linked N-acetylglucosamine (O-GlcNAc) in in vitro retinal ganglion cells (RGCs) treated with or without...

Otto Warburg, the father o f cellular bioenergetics, seems to have been the first investigator to report on inhibition o f a plant biochemical reaction by a progenitor o f a selective herbicide. The year was 1920 and the compound was phenylurethane (ethyl N-phenylcarbamate or EPC). Warburg found that it strongly inhibited photosynthesis in Chlorella. EPC did not de­ velop into a commercial herb...

O-GlcNAcylation augments vascular contractile responses, and O-GlcNAc-proteins are increased in the vasculature of deoxycorticosterone-acetate salt rats. Because endothelin 1 (ET-1) plays a major role in vascular dysfunction associated with salt-sensitive forms of hypertension, we hypothesized that ET-1-induced changes in vascular contractile responses are mediated by O-GlcNAc modification of p...

p-Nitrophenyl N-(2-mercaptophenyl)-N-methylcarbamate cyclizes rapidly at 25' to N-methylbenzothiazolone with release of p-nitrophenol. The pH-rate constant profile is sigmoidal with pK,,, = 8.7. The effective molarity of the neighboring sulfhydryl group is 1.4 X los M in comparison with bimolecular attack of thiols on p-nitrophenyl N-methyl-Nphenylcarbamate. The pH-rate constant profile for cyc...

AIMS AND BACKGROUND Protein O-linked glycosylation is regulated in vivo by the concentration of hexosamine substrates. Calorie restriction (60% of ad libitum intake) for 20 days causes decreased UDP-N-acetylhexosamine levels and increased insulin-mediated glucose transport in rat skeletal muscle. Conversely, prolonged incubation (19 h) of muscle with O-(2-acetamido-2-deoxy-D-glucopyranosylidene...

GLUCOSE, GLUTAMINE, AND GLUCOSAMINE are metabolites that can alter cardioprotection (1, 3, 8, 9, 13–15). Numerous studies suggest that one molecular mechanism by which these metabolites protect cells is though their conversion to uridine diphosphate-N-acetylglucosamine (UDP-GlcNAc) via the hexosamine biosynthetic pathway (Fig. 1) and the subsequent modification of nuclear and cytoplasmic protei...

CARDIOVASCULAR COMPLICATIONS are the leading cause of morbidity and mortality in patients with diabetes mellitus. The vascular alterations that develop in diabetic patients relate to the pathogenesis of both macrovascular (increased incidence and severity of stroke and myocardial infarction) and microvascular (neuropathy, nephropathy, retinopathy, and erectile dysfunction) systems. Endothelial ...

Primary cations of the form XCH2CH2 (1) are unstable with respect to the bridged isomer cyclo-(CH2)2X (2) or the hydride-shift isomer CH3CHX (3).Two independent hydrogen isotope experiments for X ) OH demonstrate that gaseous HOCH2CH2 (1a) gives less of its bridged isomer, protonated oxirane (2a), than of its hydride-shift isomer, protonated acetaldehyde (3a).Metastable ion decompositions of io...