高碘对脱碘酶活性影响

Study of the effect of excess iodine on deiodinases

用高碘水喂养昆明种雄性小鼠，观察到高碘水引起小鼠甲状腺相对重量增加２８．９％（Ｐ＜０．０５），甲状腺滤泡充盈扩张及上皮细胞扁平；血清Ｔ４增高３１．８％（Ｐ＜０．０１），ｒＴ３增高２９．３％（Ｐ＜０．０５），Ｔ３降低２７．３％（Ｐ＜０．０５）；肝５′－脱碘酶活性下降２６．５％（Ｐ＜０．０５）。提示高碘甲状腺肿动物血清Ｔ４增高原因是高碘抑制了分解Ｔ４的５′－脱碘酶，使Ｔ４向Ｔ３转化减少。

The Kun Ming male mice were fed with high iodine water.Three months later,the mice showed(1) the relative weight of thyroid increased by 28.9%(P<0.05),the thyroid folliculi were plentiful and dilating,and the epithelia were flat; (2) the level of serum T4 increased by 31.8%(P<0.01)and rT3 by 29.3%(P<0.05),and that of T3 decreased by 27.3%(P<0.05)and (3) the activity of 5′-Deiodinase lowered by 26.5%(P<0.05).It was considered that the increase in blood T4 could be attributable to inhibition of excess iodine from 5′-D resolving T4,resulting in decrease of conversion of T4 to T3.