Neurotoxic effects of interleukin-6 and sodium nitroprusside on cultured rat hippocampal neurons

The neurotoxicity of interleukin-6 (IL-6) and sodium nitroprusside (SNP, CA S 13755-38-9) was examined using primary cultures of rat hippocampal neuron s. The cell viability was significantly reduced after the cultures were cn- incubated with IL-6 4, 40, 400 ng/ml or SNP 1, 10, 100 mu mol/l for 23 h. I n addition, N omega-nitro-L-arginine (NNA, CAS 2149-70-4) at 0.1 mmol/l, wh en so-added with 1L-6 400 ng/ml in cultures, significantly increased IL-6 r educed viability from 78.3 +/- 6.7 % to 113.3 +/- 10.0 %. These results ind icate that IL-6 exerts neurotoxicity on cultured hippocampal neurons probab ly via overformation of nitric oxide in cultures.