Chen Xuedi, Gao Cuixia, Gong Ningning, Wang Yu, Tian Limin
Department of Endocrinology, Gansu Provincial Hospital, Lanzhou, China.
Ningxia Medical University, Yinchuan, China.
Int J Endocrinol. 2018 Mar 4;2018:8682765. doi: 10.1155/2018/8682765. eCollection 2018.
The main purpose of this study was to explore the relationships between serca2a, Ryr2, adipokines, and the left ventricular function in the subclinical hypothyroidism with different TSH levels and to determine the impact of L-T4 treatment on these indexes.
Sixty-five male Wistar rats were randomly divided into five groups: control group; sHT A, B, and C group; and sHT + T4 group. The sHT rats were induced by methimazole (MMI), and the sHT + T4 rats were administered with L-T4 treatment after 8 weeks of MMI administration. Serum TT4, TSH, APN, chemerin, and TNF- were detected by radioimmunoassay kits and ELISA kits; left ventricular function was measured by PowerLab system via subclavian artery catheter. The expression of Serca2a, Ryr2, APN, chemerin, and TNF- were detected by RT-PCR, Western blot, and immunohistochemistry.
The sHT groups had significantly higher TSH, chemerin, and TNF- and lower Serca2a, Ryr2, and APN. The left ventricular pressure and heart rate in sHT groups were significantly lower in control and sHT + T4 group. Histopathological examination revealed the pathological changes in the sHT rats' heart. L-T4 administration reduced TSH level and improved left ventricular function.
TSH can impair left ventricular function by regulating several factors, and L-T4 treatment ameliorates it in sHT rats.
本研究的主要目的是探讨不同促甲状腺激素（TSH）水平的亚临床甲状腺功能减退症中肌浆网Ca2+-ATP酶2a（serca2a）、兰尼碱受体2（Ryr2）、脂肪因子与左心室功能之间的关系，并确定左甲状腺素（L-T4）治疗对这些指标的影响。
将65只雄性Wistar大鼠随机分为五组：对照组；亚临床甲状腺功能减退症A、B和C组；以及亚临床甲状腺功能减退症+T4组。亚临床甲状腺功能减退症大鼠用甲巯咪唑（MMI）诱导，亚临床甲状腺功能减退症+T4组在MMI给药8周后给予L-T4治疗。采用放射免疫分析试剂盒和酶联免疫吸附测定试剂盒检测血清总甲状腺素（TT4）、TSH、脂联素（APN）、趋化素和肿瘤坏死因子-α（TNF-α）；通过PowerLab系统经锁骨下动脉导管测量左心室功能。采用逆转录聚合酶链反应（RT-PCR）、蛋白质免疫印迹法和免疫组织化学法检测Serca2a、Ryr2、APN、趋化素和TNF-α的表达。
亚临床甲状腺功能减退症组的TSH、趋化素和TNF-α显著升高，而Serca2a、Ryr2和APN降低。亚临床甲状腺功能减退症组的左心室压力和心率在对照组和亚临床甲状腺功能减退症+T4组中显著降低。组织病理学检查显示亚临床甲状腺功能减退症大鼠心脏有病理变化。给予L-T4可降低TSH水平并改善左心室功能。
TSH可通过调节多种因素损害左心室功能，L-T4治疗可改善亚临床甲状腺功能减退症大鼠的左心室功能。
