Lehnen Tatiana Ederich, Santos Marcus Vinicius, Lima Adrio, Maia Ana Luiza, Wajner Simone Magagnin
Thyroid Section, Endocrine Division, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre 90035-003, Rio Grande do Sul, Brazil.
Endocrinology. 2017 May 1;158(5):1502-1510. doi: 10.1210/en.2016-1586.
Nonthyroidal illness syndrome (NTIS) affects patients with myocardial infarction (MI). Oxidative stress has been implicated as a causative factor of NTIS, and reversed via N-acetylcysteine (NAC). Male Wistar rats submitted to left anterior coronary artery occlusion received NAC or placebo. Decreases in triiodothyronine (T3) levels were noted in MI-placebo at 10 and 28 days post-MI, but not in MI-NAC. Groups exhibited similar infarct areas whereas MI-NAC exhibited higher ejection fraction than did MI-placebo. Left ventricular systolic and diastolic diameters were also preserved in MI-NAC, but not in MI-placebo. Ejection fraction was positively correlated with T3 levels. Oxidative balance was deranged only in MI-placebo animals. Increased type 3 iodothyronine deiodinase expression was detected in the cardiomyocytes of MI-placebo compared with normal heart tissue. NAC was shown to diminish type 3 iodothyronine deiodinase expression and activity in MI-NAC. These results show that restoring redox balance by NAC treatment prevents NTIS- related thyroid hormone derangement and preserves heart function in rats subjected to MI.
非甲状腺疾病综合征（NTIS）会影响心肌梗死（MI）患者。氧化应激被认为是NTIS的一个致病因素，可通过N-乙酰半胱氨酸（NAC）逆转。接受左冠状动脉前降支闭塞的雄性Wistar大鼠分别给予NAC或安慰剂。在心肌梗死后10天和28天，MI-安慰剂组的三碘甲状腺原氨酸（T3）水平下降，但MI-NAC组未出现这种情况。两组梗死面积相似，但MI-NAC组的射血分数高于MI-安慰剂组。MI-NAC组的左心室收缩和舒张直径也得以保留，而MI-安慰剂组则没有。射血分数与T3水平呈正相关。仅在MI-安慰剂组动物中氧化平衡紊乱。与正常心脏组织相比，MI-安慰剂组心肌细胞中3型碘甲状腺原氨酸脱碘酶表达增加。在MI-NAC组中，NAC可降低3型碘甲状腺原氨酸脱碘酶的表达和活性。这些结果表明，通过NAC治疗恢复氧化还原平衡可预防NTIS相关的甲状腺激素紊乱，并在心肌梗死大鼠中保留心脏功能。
