碘过量摄入对雄性大鼠骨代谢的影响

目的观察碘过量摄入对雄性大鼠骨组织的毒性及损伤性作用。方法复制不同剂量的碘过量摄入雄性大鼠动物模型，并设适碘组为对照，分别喂养3、6、12个月，观察实验大鼠离体股骨和腰椎L1-4的骨密度（BMD）及骨组织形态计量学指标变化。结果摄入碘过量3个月时，雄性大鼠股骨下端骨量及骨结构参数与对照组比较差异均无统计学意义；碘过量摄入6个月时，各剂量实验组的大鼠腰椎BMD均显著升高（均P〈0．05），骨形态计量学参数表明骨代谢处于旺盛阶段；在碘过量摄入12个月时，各碘过量组均未出现骨量异常改变，但骨结构参数——骨小梁盲端数有显著升高（均P〈0．05），提示碘过量导致骨小梁出现断裂，正常的骨组织结构被破坏。结论短期碘过量摄入对雄性大鼠的骨代谢及骨组织结构不会造成严重影响，长期碘过量摄入往往会导致骨结构的破坏，雄性大鼠对碘过量的耐受性是有一定限度的。

Effect of excessive iodine intake on bone metabolism in male rats

Objective To explore possible poisonous and harmful effect of excessive iodine intake on skeleton in male rats. Methods Male rat models receiving various amounts of excessive iodine were established for 3,6, 12 months, and quantitative bone histomorphometric parameters and bone mineral density (BMD) of femur and lumbar spine( L1-1 ) were measured by means of dual-energy X-ray absorptimetry in vitro, and rats receiving normal diet were considered as control group. Results There was no significant difference in bone mineral quantity and structural parameters after feeding excessive iodine for 3 months in comparison with control group. The BMD of L1-4 was significantly increased in all animal groups when various amounts of excessive iodide was taken for 6 months (all P <0. 05). And quantitative bone histomorphometric parameters showed that the bone metabolism was in a vigorous state. After feeding excessive iodine for 12 months, BMD did not appear abnormal, whereas bone structural parameters-numbers of trabecular end were significantly increased ( all P < 0.05) , suggested that iodine excess had led to trabecular split and destroyed normal bone structure. Conclusion The bone metabolism and structure are not seriously influenced by short-term excessive iodine intake in male rats, however, the bone structure appears to be destroyed by long-term intake of excessive iodine, suggesting that the toleration of iodine excess is limited in male rats.