Purines have a recognized importance as intercellular messengers. These molecules play an important role in the development and maintenance of the central nervous system (CNS), as well as in its response to pathological conditions. Both adenine and guanine-based purines can be released from astrocytes, where they play a relevant role as extracellular signaling molecules. Particularly, the nucle...

The isolation of adenosine tetraphosphate and pentaphosphate from samples of adenosine triphosphate has been reported by Marrian (1) and Sacks (2). The available evidence is consistent with a st,ructure in which the phosphate residues are linked by phosphoanhydride bonds to one another and are carried by the 5’-hgdroxyl group of the ribose moiety (l-4). During attempts to estimate guanosine tri...

We have determined that hepsulfam, in common with its structural homologue busulfan, alkylates both free guanosine and GMP in DNA at the 7 nitrogen. Mass spectral analysis of the products of the reaction of hepsulfam with guanosine has identified the mono- and bis-alkylated guanosine adducts. UV spectrophotometry and mass spectrometry were used to confirm that alkylation occurred at the 7 nitro...

The log kobs vs. pH profiles were determined in the intermediate acidity region for the glycosyl hydrolysis of guanosine and its 8-amino, 8-monomethylamino, 8-dimethylamino and 8-bromo derivatives. The decreased rate of the 8-amino and enhanced rate of the 8-bromo compound compared to guanosine support an A type mechanism: base protonation followed by glycosyl bond cleavage. All three 8-amino g...

The sulfate ester of 7V-hydroxy-2-acetamidophenanthrene was prepared and was found to react significantly with methionine, adenosine, and guanosine. The adduci from the methionine reaction was characterized as 1-methylmercapto-2acetamidophenanthrene. The levels of reaction with adenosine and guanosine were comparable, in contrast with the observation that TV-acetoxy-2-acetamidofluorene shows a ...

The activity of RNA-dependent RNA polymerase of several influenza viruses is stimulated by guanosine. Depending upon the virus strain used, the stimulation of initial reaction rate is up to 10-fold. 5'-GMP, 3',5'-cyclic GMP, and 5'-GDP show lesser stimulation effects. No other nucleosides of 5'-NMPs stimulate, but the dinucleoside monophosphates GpG and GpC show large stimulations. We present e...

The extracellular guanosine 5'-triphosphate, GTP, has been demonstrated to be an enhancer of myogenic cell differentiation in a murine cell line, not yet in human muscle cells. Our hypothesis was that GTP could influence also human skeletal muscle regeneration, specifically in the first phases. We tested GTP stimulus on human muscle precursor cells established in culture by human satellite cell...

Controlling axon and dendrite elongation is critical in developing precise neural circuits. Using isolated cultures of dentate granule neurons, we established an experimental system that can simultaneously monitor the behaviors of axonal and dendritic outgrowth. Our previous study shows that axons and dendrites respond differentially to manipulated cyclic adenosine monophosphate signaling, but ...