Xue Liang1, Yanni Feng2, Laixiang Lin3, Iruni Roshanie Abeysekera4, Umar Iqbal5, Tingting Wang6, Ying Wang7, Xiaomei Yao8. 1. Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China. Electronic address: liangxue@tmu.edu.cn. 2. Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China. Electronic address: fengyanni@tmu.edu.cn. 3. Key Laboratory of Hormones and Development (Ministry of Health), Tianjin Key Laboratory of Metabolic Diseases, Tianjin Metabolic Diseases Hospital & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300070, China. Electronic address: linlx@tmu.edu.cn. 4. Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China. Electronic address: iruniabey@tmu.edu.cn. 5. Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China. Electronic address: umar_iq@rediffmail.com. 6. Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China. Electronic address: tingting0538@163.com. 7. Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China. Electronic address: m13820798606@163.com. 8. Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China. Electronic address: yaoxm@tmu.edu.cn.
Abstract
OBJECTIVE: Our aim was to investigate thyroid function alterations attributed to high iodide supplementation in maternal rats and their offspring. METHODS: Depending on their iodide intake, the pregnant rats were randomly divided into three groups: normal iodide intake (NI), 10 times high iodide intake (10 HI) and 100 times high iodide intake (100 HI) groups. Iodine concentration in the urine and maternal milk; iodine content and mitochondrial superoxide production; expression of TRα1, TRβ1, NIS and Dio1 in both the thyroid and mammary glands were all measured. The offspring were exposed to different iodide-containing water (NI, 10 HI and 100 HI) from weaning to postnatal day 180 (PN180). Serum thyroid hormone levels were measured in both maternal rats and their offspring. RESULTS: Iodine concentration in the urine and maternal milk, as well as iodine content in the thyroid and mammary glands was significantly increased in both the 10 HI and 100 HI groups (p < .05). In the 100 HI group of maternal rats, low FT3 levels, high FT4, TPOAb and TgAb levels were detected. In addition, an increased mitochondrial superoxide production and decreased expression of TRα1, TRβ1, NIS and Dio1 in the thyroid and mammary glands was found (p < .05). A positive staining of CD4+ that co-localized with TRβ1 in the infiltrated cells within the thyroid follicles was observed. At PN180 in the offspring, the FT3 and FT4 levels showed a significant decrease, while the levels of serum TSH, TPOAb and TgAb were significantly increased in both 10 HI and 100 HI groups (p < .05). CONCLUSION: In maternal rats, although normal thyroid function can be maintained following 10 HI, thyroiditis can be induced following 100 HI on lactation days 7, 14, and 21. In the offspring at PN180, hypothyroidism complicated with thyroiditis can occur in both the 10 HI and 100 HI groups.
OBJECTIVE: Our aim was to investigate thyroid function alterations attributed to high iodide supplementation in maternal rats and their offspring. METHODS: Depending on their iodide intake, the pregnant rats were randomly divided into three groups: normal iodide intake (NI), 10 times high iodide intake (10 HI) and 100 times high iodide intake (100 HI) groups. Iodine concentration in the urine and maternal milk; iodine content and mitochondrial superoxide production; expression of TRα1, TRβ1, NIS and Dio1 in both the thyroid and mammary glands were all measured. The offspring were exposed to different iodide-containing water (NI, 10 HI and 100 HI) from weaning to postnatal day 180 (PN180). Serum thyroid hormone levels were measured in both maternal rats and their offspring. RESULTS:Iodine concentration in the urine and maternal milk, as well as iodine content in the thyroid and mammary glands was significantly increased in both the 10 HI and 100 HI groups (p < .05). In the 100 HI group of maternal rats, low FT3 levels, high FT4, TPOAb and TgAb levels were detected. In addition, an increased mitochondrial superoxide production and decreased expression of TRα1, TRβ1, NIS and Dio1 in the thyroid and mammary glands was found (p < .05). A positive staining of CD4+ that co-localized with TRβ1 in the infiltrated cells within the thyroid follicles was observed. At PN180 in the offspring, the FT3 and FT4 levels showed a significant decrease, while the levels of serum TSH, TPOAb and TgAb were significantly increased in both 10 HI and 100 HI groups (p < .05). CONCLUSION: In maternal rats, although normal thyroid function can be maintained following 10 HI, thyroiditis can be induced following 100 HI on lactation days 7, 14, and 21. In the offspring at PN180, hypothyroidism complicated with thyroiditis can occur in both the 10 HI and 100 HI groups.