母鼠碘过量对子代甲状腺功能及学习记忆能力的影响

Influence of maternal rat iodine excess on thyroid function and learning-memory ability of offspring

目的研究母鼠高碘摄入对子代甲状腺功能及学习记忆能力产生的影响。方法将断乳2 w的SPF级雌性Wistar大鼠,按体重分层随机分为重度碘过量组(SIE)、轻度碘过量组(MIE)和适碘对照组(NI),各组动物均给予碘饲料,以自由饮水加入不同浓度碘化钾构建不同程度碘过量水平动物模型,模型建立成功后雌雄合笼,对子代进行Morris水迷宫实验并测定甲状腺激素水平。结果3个组子代FT4水平差异有统计学意义(F=9.516,P<0.05);3个组甲状腺球蛋白抗体(χ^(2)=14.268)、抗甲状腺球蛋白抗体(χ^(2)=35.660)和双抗体阳性率(χ^(2)=11.786)差异均有统计学意义(P<0.05);定位航行实验结果显示,第二天(F=5.356)和第三天(F=13.442)3个组间差异均有统计学意义(P<0.05);空间探索实验结果显示,3个组子代有效区域运动时间(F=3.876)和穿越平台次数(χ^(2)=6.372)差异有统计学意义(P<0.05),穿越平台次数SIE组(Z=-1.967)和MIE组(Z=-2.285)均少于NI组(P<0.05),有效区域运动时间SIE组较NI组缩短(t=3.141),差异有统计学意义(P<0.05)。结论亲代雌鼠碘摄入过量可导致子代甲状腺功能异常并损伤其学习记忆能力,且不同的碘过量程度所造成的影响也不相同。

Objective To investigate the influence of excessive iodine intake of maternal rat to the thyroid function and learning-memory ability of offspring.Methods According to the body weight,the SPF female Wistar rats which weaned two weeks were randomly divided into severe iodine excess group(SIE),mild iodine excess group(MIE)and normal iodine control group(NI).The rats of all groups were given iodine-containing feed,and the animal models with different levels of iodine excess were set up when the different concentrations of potassium iodate adding in the free drinking water.After models were successfully established,the female rats were caged with male rates.The Morris water maze and the thyroid hormone levels were tested in their offspring.Results There was statistical difference in FT4 levels among the offspring of three groups(F=9.516,P<0.05),and the differences were significant(P<0.05)in the positive rates of TgAb(χ^(2)=14.268),TPOAb(χ^(2)=35.660)and di-antibody(χ^(2)=11.786)among the three groups.The results of the positioning cruise test showed statistical differences(P<0.05)in second day(F=5.356)and third day(F=13.442)among three groups.The results of space exploration experiment of offspring showed statistical differences(P<0.05)in the effective area movement time(F=3.876)and target-platform crossing times(χ^(2)=6.372)among three groups.The number of target-platform crossing times in SIE group(Z=-1.967)and MIE group(Z=-2.285)were less than that in NI group(P<0.05).The effective area movement time in SIE group was shorter than that in NI group(t=3.141)with statistical difference(P<0.05).Conclusions Excessive iodine intake of parental female rats can causes the thyroid dysfunction in their offspring and damage the learning-memory ability of their offspring,and the influences are also different in each levels of iodine excess.