1. Reinshagen M, Schutz E, Armstrong VW, Behrens C, von Tirpitz C, Stallmach A, et al. 6-thioguanine nucleotide-adapted azathioprine therapy does not lead to higher remission rates than standard therapy in chronic active Crohn disease: results from a randomized, controlled, open trial. Clin Chem 2007;53:1306–14. 2. Shipkova M, Armstrong VW, Wieland E, Oellerich M. Differences in nucleotide hydr...

Chinese hamster ovary cells synchronized by mitotic detachment were treated with 5-fluorodeoxyuridine (FdUrd), 0.2 micrograms/ml, at various times in the cell cycle. FdUrd treatment in the early S period induced resistance to 6-thioguanine. Treatment of asynchronous cells with FdUrd caused little increase in 6-thioguanine resistance over the spontaneous frequency. Mitotic selection thus enhance...

6-Thioguanine (3) has been shown to inhibit a wide spectrum of neoplasms. Its anti-tumor prop erties are markedly potentiated when combined with azaserine, an inhibitor of the synthesis de novo of purines (10, 13). One of these reports also indicated that, for maximum effect, the antimetabolites had to be administered simultaneous ly. These results suggest that thioguanine inter feres with some...

Purine analogues were used in this study to dissect specific steps in the mechanism of action of nerve growth factor (NGF). Protein kinase N (PKN) is an NGF-activated serine protein kinase that is active in the presence of Mn++. The activity of PKN was inhibited in vitro by purine analogues, the most effective of which was 6-thioguanine (apparent Ki = 6 microM). Several different criteria indic...

ase is also described. Radioactivity in plasma, brain, and muscle was determined after administration of 6-mercap topurine, 6-mercaptopurine ribonucleoside, 6-thioguanine, or 6-thioguanine ribonucleoside in mice or rats. At the times chosen for tissue sampling, there were no major differences in brain uptake between the base and ribonu cleoside pairs. Muscle radioactivity ranged from 3 to 7 tim...