TOXICITY OF DOPAMINE TO MOUSE NEUROBLASTOMA-X RAT GLIOMA HYBRID (NG108) CELLS IN-VITRO

AIM: To study toxicity of dopamine to mouse neuroblastoma X rat glioma hybrid (NG108) cells. METHODS: Cell viability was estimated using [4, 5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. R ESULTS: Dopamine at 100 mu mol L(-1) was toxic when added to cultures 24 h after plating. The cell viability was about 1/4 of control. Toxic ity did not seem to be mediated by dopaminergic receptors because the dopaminergic antagonists sulpiride and Sch-23390 did not block the tox ic effect of dopamine. Catalase 50 kU L(-1), superoxide dismutase 50 k U L(-1) and l-ascorbic acid 200 mu mol L(-1) blocked the dopamine (125 mu mol L(-1)) toxicity and elevated the cell viability from 25.9 +/- 11.0 % to 74.8 +/- 4.4 %, 72.3 +/- 4.5 % and 71.4 +/- 2.3 %, respectiv ely. CONCLUSION: Dopamine toxicity to NG108 cells was mainly attribute d to the oxidation of dopamine and its toxic by-products, eg, H2O2.