Mitochondrial perturbation and oxidative stress are key factors in neuronal vulnerability in several neurodegenerative diseases or during brain ischemia. Here we have investigated the protective mechanism of action of guanosine, the guanine nucleoside, in a human neuroblastoma cell line, SH-SY5Y, subjected to mitochondrial oxidative stress. Blockade of mitochondrial complexes I and V with roten...

We observed the nonenzymatic formation of guanosine 3’:5’-monophosphate (cyclic GMP) from GTP. The reaction was dependent upon heat and was accelerated by divalent cations and creatine phosphate. The formation of cyclic GMP was greater with increased incubation time, temperature, GTP concentration, and pH. All of the divalent cations tested (Mg2+, Mnz+, Ca2+, Ba2+, and Znzf) increased cyclic GM...

Chaykin, S., Law, J., Phillips, A. H., Tchen, T. T. & Bloch, K. (1958). Proc. nat. Acad. Sci., Wash., 44, 998. Cornforth, J. W., Cornforth, R. H., Popjak, G. & Gore, I. Y. (1958). Biochem. J. 69, 146. de Waard, A. (1958). Doctoral Thesis: University of Utrecht, Holland; Investigations on the intermediates in the biosynthesis of fatty acids and cholesterol. Nijmegen: Drukkerij Gebr. Janssen. de ...

BACKGROUND AND PURPOSE Stroke is a devastating disease. Both excitotoxicity and oxidative stress play important roles in ischemic brain injury, along with harmful impacts on ischemic cerebral tissue. As guanosine plays an important neuroprotective role in the central nervous system, the purpose of this study was to evaluate the neuroprotective effects of guanosine and putative cerebral events f...

In cultured renal cells and isolated perfused kidneys, extracellular guanosine augments extracellular adenosine and inosine (the major renal metabolite of adenosine) levels by altering the extracellular disposition of these purines. The present study addressed whether this "guanosine-adenosine mechanism" exists in vivo. In rats (n = 15), intravenous infusions of adenosine (1 µmol/kg per minute)...

Minicells of Escherichia coli DS410 synthesized guanosine-5'-diphosphate-3'-diphosphate and guanosine-5'-triphosphate-3'-diphosphate when synthesizing proteins in response to phage T7 infection. The guanosine-5'-diphosphate-3'-diphosphate synthesis was found to be relA+ dependent and inhibited by chloramphenicol.

Certain C8-substituted and N7, C8-disubstituted guanine ribonucleosides comprise a class of small molecules with immunostimulatory activity. In a variety of animal models, these agents stimulate both humoral and cellular immune responses. The antiviral actions of these guanosine analogs have been attributed to their ability to induce type I IFNs. However, the molecular mechanisms by which the g...

Previous studies showed that the carcinogen N-hydroxy-2fluorenylacetamide could react with RNA following enzymatic activation of the hydroxamic acid by deacetylation or esterification. Present studies indicate that 2’-(3’)-GMP, but not 2’-(3’)-AMP, -CMP, or -UMP, competes effectively with RNA in these reactions. &(N-Z-Fluorenylamino)guanosine was isolated and identified after incubation of guan...

BACKGROUND/AIM Mycophenolate mofetil could be a useful antiproliferative drug in glaucoma filtering surgery. In this study the authors set out to investigate whether growth inhibition of mycophenolate mofetil on human Tenon fibroblasts is mediated by guanosine depletion. METHODS Cultured human Tenon fibroblasts were incubated in various concentrations of mycophenolate mofetil with and without...