Dietary high-fat lard intake induces thyroid dysfunction and abnormal morphology in rats
Dietary high-fat lard intake induces thyroid dysfunction and abnormal morphology in rats
复制标题
膳食高脂猪油摄入诱发大鼠甲状腺功能障碍和形态异常
DOI：
10.1038/aps.2014.82
复制
发表时间：
2014-11-01
影响因子：
8.2
通讯作者：
Zhao, Jia-jun
中科院分区：
文献类型：
--
作者：
Shao, Shan-shan;Zhao, Yuan-fei;Zhao, Jia-jun
目的：过量膳食脂肪摄入可引起非脂肪组织的脂毒性。本研究的目的是观察饮食中摄入高脂猪油对大鼠甲状腺的影响。方法：雄性Sprague-Dawley大鼠饲喂高脂猪油饮食24周，然后再饲喂正常对照饮食（急性饮食调整）或高脂猪油饮食6周。在第12、18、24和30周时测定血清脂质谱、总甲状腺素（TT4）、游离甲状腺素（FT4）和促甲状腺素（TSH）水平。在第 24 周或第 30 周时对甲状腺进行高频超声扫描。处死大鼠后，收集甲状腺进行组织学和免疫组化分析。结果：高脂猪油饮食显着升高血清和甲状腺中的甘油三酯水平，并降低血清TT4和FT4水平，同时升高血清TSH水平。超声成像显示，高脂猪油喂养的大鼠甲状腺肿大，回声纹理降低，且特征相对异质。高脂猪油喂养大鼠甲状腺光镜下可见滤泡腔增大、滤泡上皮细胞扁平，透射电镜下内质网池扩张、细胞核扭曲、微绒毛和分泌小泡减少。此外，高脂猪油喂养的大鼠的甲状腺中甲状腺激素合成相关蛋白TTF-1和NIS的水平明显较低。通过停止高脂猪油饮食6周的急性饮食调整未能改善高脂猪油饮食引起的甲状腺变化。结论：膳食高脂猪油摄入可导致大鼠显着的甲状腺功能障碍和形态异常，且不能通过短期饮食调整来纠正。
Aim: Excess dietary fat intake can induce lipotoxicity in non-adipose tissues. The aim of this study was to observe the effects of dietary high-fat lard intake on thyroid in rats.Methods: Male Sprague-Dawley rats were fed a high-fat lard diet for 24 weeks, and then the rats were fed a normal control diet (acute dietary modification) or the high-fat lard diet for another 6 weeks. The serum lipid profile, total thyroxine (TT4), free thyroxine (FT4) and thyrotropin (TSH) levels were determined at the 12, 18, 24 and 30 weeks. High-frequency ultrasound scanning of the thyroid glands was performed at the 24 or 30 weeks. After the rats were sacrificed, the thyroid glands were collected for histological and immunohistochemical analyses.Results: The high-fat lard diet significantly increased triglyceride levels in both the serum and thyroid, and decreased serum TT4 and FT4 levels in parallel with elevated serum TSH levels. Ultrasonic imaging revealed enlarged thyroid glands with lowered echotexture and relatively heterogeneous features in the high-fat lard fed rats. The thyroid glands from the high-fat lard fed rats exhibited enlarged follicle cavities and flattened follicular epithelial cells under light microscopy, and dilated endoplasmic reticulum cisternae, twisted nuclei, fewer microvilli and secretory vesicles under transmission electron microscopy. Furthermore, the thyroid glands from the high-fat lard fed rats showed markedly low levels of thyroid hormone synthesis-related proteins TTF-1 and NIS. Acute dietary modification by withdrawal of the high-fat lard diet for 6 weeks failed to ameliorate the high-fat lard diet-induced thyroid changes.Conclusion: Dietary high-fat lard intake induces significant thyroid dysfunction and abnormal morphology in rats, which can not be corrected by short-term dietary modification.