Effects Of Fluoride And Arsenic On The Cerebral Development And Learning -memory Ability Of Rats

96 healthy wistar rats were randomly divided into 4 groups (24 for each group): The rats were exposed to high fluoride drinking water(100mg/L NaF), high arsenic drinking water (50mg/L As2O3 ) or both together in order to assess the effects of these three factors on the Cerebral development and Learning-memory ability of rats. When the rats were treated for 10 , 30, 60 and 90 days respectively, the step-down test was performed to measure the learning and memory abilities of rats.and then some related biochemical indexes and serum hormone were detected. At last, DNA damage of brain cells were measured by Single Cell Gel Electrophoresis (SCGE )and the changes of pathological state in cerebrum were observed by microscope at the same time . The result indated:1.In comparison with the control, EN1 and EN2 of the experimental rats all increased , but only High Fluoride and Arsenic(HFA ) group did significantly ( p<0.05 ) .And ST of the experimental rats decreased obviously compared with the control ( P<0.05 ) .2. In the test of AchE activity,High Fluoride(HF) group and HFA deceased obviously compared with the control(P<0.05)when treated for 10 days, while High Arsenic(HA) increased significantly when treated for 30 days,and in the late stage of the experiment, AchE activity of HFA was lower than the control dramatically ( P<0.01 ) .As for hydrosulfide group (-SH) contents of brains, HA was lower than the control obviously (P<0.05 ) , but there was no significant difference between HF and the control, HFA was lower than the control notably only when treated for 90d( p<0.05 XThe total antioxidation capacity (T-AOC)of the experimental rats brain decreased prevalently , of Which HA and HFA were lower than the control obviously (P<0.05) when treated for 10,30,90d, and only when treated for 10d, HF decreased markedly compared with the control ( P<0.05) .3.About T3 content in serum , when treated for 60d, HF and HA decreased dramatically compared with the control (P<0.01) ,but when treated for 90d, the three experimental group are all higher than the control and HFA group was higher dramatically than the control (P<0.01) .As for T4, when treated for 10d, HF and HA decreased markedly (P<0.05) ,for 30 and 60d HFA decreased obviously (P<0.05) , and for 60d HA was lower than the control dramatically (P<0.01) .About TSH, when treated for 10d three experimental groups were all higher than the control obviously (P<0.05) , and for 30 and 60d the above groups were still higher than the control,but no statistically difference ( P>0.05) .When treated for 90d ,HF and HA were higher than the control (P<0.05) .4.SCGE results showed:high fluoride,high arsenic or both together may all cause DNA damage of the brain cells in rats. And the tailing rates of the experimental group were dramatically higher than the control (P<0.01 ) , â…¡and â…¢ grade damage of three experimental group were respectively 72.74%, 68.58% and 72.83%. This suggested that brain cell damage caused by both together was most serious.