Long-term drinking purified water may aggravate the inhibition of NMDA expression and spatial learning ability induced by lead on rat / 中华预防医学杂志

<p><b>OBJECTIVE</b>To compare brain lead accumulation and neurotoxicity induced by lead under drinking purified water and tap water on rat.</p><p><b>METHODS</b>All 104 male weaning SD rats were randomly divided into eight groups, matched-four pairs according to drinking water: tap water, purified water, tap water with lead 50 mg/L(lead acetate water-solution), purified water with lead 50 mg/L, tap water with lead 200 mg/L, purified water with lead 200 mg/L, tap water with lead 800 mg/L. All were fed with normal food and environmental cognitions kept consistent Morris water maze(including Place Navigation, Spatial Probe Test, Visible Platform Trial) was measured to test rat spatial learning at the 12 and 24 week. At the end of the experiment (28 week), rats were killed and the lead of brain and blood was measured by Graphite furnace atomic absorption spectrometric method; the NR1, NR2A, NR2B of NMDAR (N-methyl-D-aspartame receptor) in hippocampus were analyzed by RT-PCR.</p><p><b>RESULTS</b>Under the same lead exposure, no significant differences were observed in blood lead, however, brain lead level showed higher in drinking purified water group than that in tap water group. Expression of NR1, NR2A and NR2B in hippocampus of the rats drinking purified water was lower than those drinking tap water, especially at low lead exposure (50 mg/L) (P < 0.05). In the 24 week Morris water maze, place navigation test's escape latency showed significantly prolonged at the rats drinking purified water as compared with those drinking tap water on the pairs of 50 mg/L and 200 mg/L pb2+ groups (P < 0.05), and the differences occurred in early 1-2 days.</p><p><b>CONCLUSION</b>Compared with drinking tap water, drinking purified water might increase the accumulation of brain lead, lower NR1, NR2A, NR2B expression and delay the spatial learning and memory ability under chronic lead exposure in water.</p>

Effect of Arsenic Exposure through Drinking Water on the Levels of Blood Arsenic and Brain Arsenic,Learning and Memory of Rats / 环境与健康杂志

Objective To investigate the effect of arsenic exposure on learning and memory ability of rats.Methods Fourty- eight weaned SD rats were randomly divided into four groups,12 in each.The control group drank tap water,the other three groups treated with sodium arsenite at doses of 2.72 mg/L,13.6 mg/L and 68 mg/L for 12 weeks.Morris water maze was used to test the spatial learning and memory ability of rats.Arsenic level in the blood and brain was assessed after Morris water maze test.Results Arsenic contents in the blood of arsenic exposed rats were significantly higher than that in control rats(P