Expression of neuropeptide Y by glutamatergic stimulation in rat C6 gliomacells

We have investigated the expression of neuropeptide Y (NPY) in C6 glioma ce lls after the glutamatergic stimulation by the in situ RT-PCR and immunocyt ochemical techniques. The expression of NPY mRNA correlated well with immun ocytological findings in each series of experiments. NPY protein expression was enhanced by glutamate (1, 10, 50, 100 mu M, and 1 mM) dose-dependently , and its expression was slightly increased by N-methyl-D-aspartate (NMDA; 1, 10, 100, 500 mu M, and 1 mM) and kainic acid (1, 10, 100, 300 mu M, and 1 mM). We pretreated the cells with dopamine, haloperidol, pentylenetetrazo l, and muscimol before each stimulation. The pentylenetetrazol and muscimol did not significantly alter the patterns of NPY expression induced by the glutamatergic stimulation. On the other hand, the dopamine and haloperidol pretreatment significantly elevated the levels of NPY expression that were induced by NMDA and kainic acid. Our results indicate that NPY release is c losely related to glutamatergic stimulation, and it could be dynamically me diated by GABAergic and dopaminergic costimulation. (C) 1999 Elsevier Scien ce Ltd. All rights reserved.