摘要
目的 探讨碘缺乏和碘过多对甲状腺细胞膜脂流动性的影响及其作用机理。方法 观察不同碘摄入水平的 3组Wistar大鼠血清T4 、T3水平 ,甲状腺组织超氧化物歧化酶 (SOD)和谷胱甘肽过氧化物酶 (GPx)的活力以及脂质过氧化产物丙二醛 (MDA)含量 ,应用荧光偏振方法测量了甲状腺细胞膜脂的荧光偏振度和平均微黏度 ,以反映膜脂的流动性。结果 低碘组大鼠血清T4 、T3 水平显著低于适碘对照组及高碘组 ,SOD和GPx活力以及MDA含量明显高于其他 2组。而高碘组的上述指标与对照组差异均无显著性意义。实验 12周时 3组间荧光偏振度和平均微黏度差异均无显著性意义 ,但在 2 4周时低碘组 2项指标均显著高于适碘对照组及高碘组 ,而高碘组未见明显变化。结论 长期碘缺乏导致了甲状腺膜脂流动性变小 ,黏度变大 ,其发生机理与甲状腺脂质过氧化损伤有关。碘缺乏使T4 、T3 合成减少 ,导致脂质代谢障碍 ,也是重要的发生因素之一。
Objectives To explore the effect of iodine deficiency and excess on thyroid membrane fluidi ty and its pathogenesis. Methods Wistar rats were fed different levels of iodine in the diet (normal iodine as control, low iodine and excess iodine). Serum T 4 and T 3 levels, thyroid superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities and malondialdehyde (MDA) content were determined, and two parameters of polarization (Pr) and micro-viscosity (η) using DPH as a florescence probe were tested. Results Serum T 4 and T 3 levels in the low iodine (LI) group were markedly decreased, and the thyroid SOD and GPx activities and MDA content were significantly increased compared with the other two groups. However no cha nges were found in the high iodinje (HI) group. There were no differences in Pr an d η values among three groups at 12th week of experiment, but at 24th week, bot h Pr and η values in LI group were increased significantly compared to the othe r two groups. But the effect of iodine excess as expected was not found in this s tudy. Conclusions Long-term iodine deficiency caused a marked increa se of membrane micro-viscosity and decrease of membrane fluidity in rat thyroid gland. Oxidative damage of thyroid by free radicals and retardation of l ipid metabolism are considered as two important pathogenesis factors.
出处
《中华预防医学杂志》
CAS
CSCD
北大核心
2000年第5期266-268,共3页
Chinese Journal of Preventive Medicine
基金
国家自然科学基金!资助 (39870 6 82 )
关键词
甲状腺
细胞膜脂流动性
碘缺乏症
碘过多
Iodine； Deficiency diseases； Thyr oid gland； Membrane fluidity
