Alternatively Spliced Methionine Synthase in SH-SY5Y Neuroblastoma Cells: Cobalamin and GSH Dependence and Inhibitory Effects of Neurotoxic Metals and Thimerosal

Figure 4

Metal ions and thimerosal inhibit MS activity and decrease levels of GSH in SH-SY5Y cells. Concentration-dependent inhibition of MeCbl and OHCbl-based MS activity by (a) lead, (b) arsenic, (c) aluminum, or (d) mercury. MS activity was measured at 100 μM 5-methylTHF. and versus untreated group. (e) Cellular GSH levels after a 1 hr treatment (100 nM) with lead, arsenic, aluminum, mercury, or thimerosal.    and versus untreated group. (f) Cellular uptake of cysteine measured after a 1 hr treatment (100 nM) with lead, arsenic, aluminum, mercury, or thimerosal. and versus untreated group.

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