P7 rats were injected with saline or MeHg (5µg/gbw) and received 5 repeated injections of NAC (10µg/gbw per injection) over 8 hours with 2 hours intervals between each injection. NAC exposure was initiated 2 hours before MeHg exposure. A: [3H]-Thy incorporation into the whole hippocampus was measured 24 hours after MeHg exposure. The inhibitory effect of MeHg on DNA synthesis was almost completely abolished by NAC. B: ICP-MS measurement of hippocampal mercury content 24 hours after treatment with NAC and/or MeHg. Mercury was almost undetectable in the control and NAC treated animals. MeHg sc injection led to a massive Hg uptake into the hippocampus, which was significantly reduced by NAC. Values are expressed as the means ± sem of 4 independent experiments for all groups, with 3 animals per group in each experiment (N=12 per group). **, P < 0.01 vs control; ***, P < 0.001 vs control; #, P < 0.05 vs MeHg; ##, P < 0.01 vs MeHg.