Abstract：
UNASSIGNED: Thyroid function depends on iodine uptake by the body as well as on exposure to various harmful environmental hazards (stress, ionizing radiation).
UNASSIGNED: The aim of the work was to assess the effect of exposure to low and intermediate doses of external γ-radiation on the thyroid structure and function in young female rats at remote periods after radiation.
UNASSIGNED: Forty female rats were used to study remote effects of external γ-radiation exposure during 20 d (at daily doses of 0.1, 0.25 and 0.5 Gy) on the functional activity (levels of thyroid hormones, iodine metabolism) and the morphological structure of the rat thyroid) after 12 months following the radiation exposure.
UNASSIGNED: An increase in thyroid mass and a decrease in total thyroid protein concentration along with a reduction of blood T3 and T4 was shown only in rat groups exposed to 0.25 and 0.5 Gy. Both the concentration of total iodine and its protein-bound fraction (1.2-1.4 fold, p < .01) and the protein-bound to total iodine ratio were decreased in the thyroids of all irradiated animals. The 0.1-Gy group showed elevated thyroperoxidase (TPO) activity along with increased catalase activity, which may indicate the activation of iodine oxidation by thyrocytes. Only the 0.5-Gy group demonstrated reduced urinary excretion of iodine (2.1 fold, p < .01).The reduction of thyroid function at radiation doses of 0.25 and 0.5 Gy was characterized by a microfollicular structure and the development of atrophic changes in the parenchyma, desquamation of thyroid epithelium and an increase in epithelium proliferation. The diameter of the thyrocyte nuclei was increased in rats exposed to 0.25 and 0.5 Gy, which indicates functional tension of thyrocytes.
UNASSIGNED: Our research shows that after a year, the exposure to external γ-radiation of 0.1, 0.25 and 0.5-Gy caused changes in the structure and function of the rat thyroid which are manifested by the development of hypothyroiditis (0.5 Gy), \'subclinical\' hypothyroiditis (0.25 Gy) and functional tension of thyrocytes. The mechanisms of thyroid dysfunction - impaired- uptake of iodine and its organification against the background of activation of free radical processes - suggest disturbances in the function of the sodium/iodide symporter (NIS), TPO and thyroglobulin synthesis. In contrast to the intermediate doses, the effects of the 0.1-Gy dose were mostly found at the remote periods compared to the earlier periods (180 days).
UNASSIGNED: The aim of the work was to assess the effect of exposure to low and intermediate doses of external γ-radiation on the thyroid structure and function in young female rats at remote periods after radiation.
UNASSIGNED: Forty female rats were used to study remote effects of external γ-radiation exposure during 20 d (at daily doses of 0.1, 0.25 and 0.5 Gy) on the functional activity (levels of thyroid hormones, iodine metabolism) and the morphological structure of the rat thyroid) after 12 months following the radiation exposure.
UNASSIGNED: An increase in thyroid mass and a decrease in total thyroid protein concentration along with a reduction of blood T3 and T4 was shown only in rat groups exposed to 0.25 and 0.5 Gy. Both the concentration of total iodine and its protein-bound fraction (1.2-1.4 fold, p < .01) and the protein-bound to total iodine ratio were decreased in the thyroids of all irradiated animals. The 0.1-Gy group showed elevated thyroperoxidase (TPO) activity along with increased catalase activity, which may indicate the activation of iodine oxidation by thyrocytes. Only the 0.5-Gy group demonstrated reduced urinary excretion of iodine (2.1 fold, p < .01).The reduction of thyroid function at radiation doses of 0.25 and 0.5 Gy was characterized by a microfollicular structure and the development of atrophic changes in the parenchyma, desquamation of thyroid epithelium and an increase in epithelium proliferation. The diameter of the thyrocyte nuclei was increased in rats exposed to 0.25 and 0.5 Gy, which indicates functional tension of thyrocytes.
UNASSIGNED: Our research shows that after a year, the exposure to external γ-radiation of 0.1, 0.25 and 0.5-Gy caused changes in the structure and function of the rat thyroid which are manifested by the development of hypothyroiditis (0.5 Gy), \'subclinical\' hypothyroiditis (0.25 Gy) and functional tension of thyrocytes. The mechanisms of thyroid dysfunction - impaired- uptake of iodine and its organification against the background of activation of free radical processes - suggest disturbances in the function of the sodium/iodide symporter (NIS), TPO and thyroglobulin synthesis. In contrast to the intermediate doses, the effects of the 0.1-Gy dose were mostly found at the remote periods compared to the earlier periods (180 days).
摘要：
■甲状腺功能取决于人体对碘的摄取以及暴露于各种有害环境危害（压力，电离辐射)。
■这项工作的目的是评估暴露于低剂量和中等剂量的外部γ辐射对年轻雌性大鼠在辐射后偏远时期的甲状腺结构和功能的影响。
■使用40只雌性大鼠研究了20天（每日剂量为0.1、0.25和0.5Gy）外部γ辐射暴露对功能活动（甲状腺激素水平，碘代谢）和大鼠甲状腺的形态结构）在辐射暴露后12个月。
■仅在暴露于0.25和0.5Gy的大鼠组中显示出甲状腺质量的增加和总甲状腺蛋白浓度的降低以及血液T3和T4的降低。总碘浓度及其蛋白质结合分数（1.2-1.4倍，p<.01），并且在所有受照射的动物的甲状腺中，蛋白质结合与总碘的比率均降低。0.1-Gy组显示甲状腺过氧化物酶（TPO）活性升高，过氧化氢酶活性增加，这可能表明甲状腺细胞激活了碘氧化。只有0.5-Gy组显示出碘的尿排泄减少（2.1倍，p<.01)。在0.25和0.5Gy的辐射剂量下，甲状腺功能降低的特征是微滤泡结构和实质萎缩性变化的发展，甲状腺上皮脱皮和上皮增殖增加。暴露于0.25和0.5Gy的大鼠甲状腺细胞核的直径增加，这表明甲状腺细胞的功能张力。
■我们的研究表明，一年后，暴露于0.1、0.25和0.5-Gy的外部γ辐射引起大鼠甲状腺结构和功能的变化，表现为低甲状腺炎（0.5Gy）的发展，亚临床甲状腺炎(0.25Gy)和甲状腺细胞功能紧张。甲状腺功能障碍的机制-在自由基过程激活的背景下，碘的摄取及其组织作用受损-提示钠/碘转运体（NIS）的功能紊乱，TPO和甲状腺球蛋白合成。与中间剂量相比，与早期时期(180天)相比,0.1Gy剂量的影响主要出现在偏远时期.
■这项工作的目的是评估暴露于低剂量和中等剂量的外部γ辐射对年轻雌性大鼠在辐射后偏远时期的甲状腺结构和功能的影响。
■使用40只雌性大鼠研究了20天（每日剂量为0.1、0.25和0.5Gy）外部γ辐射暴露对功能活动（甲状腺激素水平，碘代谢）和大鼠甲状腺的形态结构）在辐射暴露后12个月。
■仅在暴露于0.25和0.5Gy的大鼠组中显示出甲状腺质量的增加和总甲状腺蛋白浓度的降低以及血液T3和T4的降低。总碘浓度及其蛋白质结合分数（1.2-1.4倍，p<.01），并且在所有受照射的动物的甲状腺中，蛋白质结合与总碘的比率均降低。0.1-Gy组显示甲状腺过氧化物酶（TPO）活性升高，过氧化氢酶活性增加，这可能表明甲状腺细胞激活了碘氧化。只有0.5-Gy组显示出碘的尿排泄减少（2.1倍，p<.01)。在0.25和0.5Gy的辐射剂量下，甲状腺功能降低的特征是微滤泡结构和实质萎缩性变化的发展，甲状腺上皮脱皮和上皮增殖增加。暴露于0.25和0.5Gy的大鼠甲状腺细胞核的直径增加，这表明甲状腺细胞的功能张力。
■我们的研究表明，一年后，暴露于0.1、0.25和0.5-Gy的外部γ辐射引起大鼠甲状腺结构和功能的变化，表现为低甲状腺炎（0.5Gy）的发展，亚临床甲状腺炎(0.25Gy)和甲状腺细胞功能紧张。甲状腺功能障碍的机制-在自由基过程激活的背景下，碘的摄取及其组织作用受损-提示钠/碘转运体（NIS）的功能紊乱，TPO和甲状腺球蛋白合成。与中间剂量相比，与早期时期(180天)相比,0.1Gy剂量的影响主要出现在偏远时期.
