Nitric Oxide Synthase Expression in Glial Cells: Suppression by Tyrosine Kinase Inhibitors
Version of Record online: 23 NOV 2002
Journal of Neurochemistry
Volume 62, Issue 2, pages 811–814, February 1994
How to Cite
Feinstein, D. L., Galea, E., Cermak, J., Chugh, P., Lyandvert, L. and Reis, D. J. (1994), Nitric Oxide Synthase Expression in Glial Cells: Suppression by Tyrosine Kinase Inhibitors. Journal of Neurochemistry, 62: 811–814. doi: 10.1046/j.1471-4159.1994.62020811.x
- Issue online: 23 NOV 2002
- Version of Record online: 23 NOV 2002
- Resubmitted manuscript received October 18, 1993; accepted October 26, 1993.
- C6 cells;
Abstract: Rat brain glial cells have the capacity to express a calcium-independent form of nitric oxide synthase (iNOS). To test if iNOS induction required tyrosine kinase activity, we made use of genistein, a selective inhibitor of tyrosine kinases. In both primary astrocyte cultures and C6 glioma cells, the presence of genistein prevented both lipopolysaccharide- and cytokine-induced NOS activity in a dose-dependent manner. The presence of tyrphostin-25 (10 µM), which is highly specific for tyrosine kinases, also blocked iNOS induction. Additional characterization showed that genistein blocked iNOS induction in a dose-dependent manner (IC50 of ∼ 40 µM), that the continuous presence of genistein was not necessary to observe inhibition, and that preincubation with genistein led to higher levels of inhibition than the simultaneous addition of genistein and inducers. The decrease in iNOS activity due to genistein was accompanied by a decrease in iNOS mRNA level as detected by a specific PCR assay. These results indicate that induction of astroglial iNOS expression requires tyrosine kinase activity.