Department of Physiology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Department of Physiology, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran.
Respir Physiol Neurobiol. 2020 Jun;277:103437. doi: 10.1016/j.resp.2020.103437. Epub 2020 Apr 5.
In this study, the effect of levothyroxine (L-T4) on tracheal responsiveness, lung inflammation, oxidative stress and pathological features in a rat model of Alzheimer's disease (AD), was evaluated.
An animal model of AD was established by intracerebroventricular injection of streptozotocin (STZ) (3 mg/kg) in rats. The rats were then treated for 3 weeks with L-T4 (10 and 100 μg/kg).
In AD animals, tracheal responsiveness to methacholine and ovalbumin (p < 0.05), white blood cell (WBC) count (p < 0.05 to p < 0.01), malondialdehyde (MDA) concentration (p < 0.05) and inflammation score (p < 0.01) were increased, but superoxide dismutase (SOD) activity and total thiol content (for both cases p < 0.05) were decreased compared to the controls. Tracheal responsiveness to methacholine and MDA concentration (p < 0.05) were decreased in AD animals treated with T4 compared to the AD group. Bronchial inflammation in terms of total and some differential WBC in the BALF and inflammatory score, was significantly worsened in AD animals treated with high dose of T4 (p < 0.05 to p < 0.001) compared to the controls.
Alzheimer's disease may cause lung inflammation and treatment with low dose of T4 improved MDA level and lung inflammation.
在这项研究中，评估了左甲状腺素（L-T4）对阿尔茨海默病（AD）大鼠模型中气管反应性、肺部炎症、氧化应激和病理特征的影响。
通过向大鼠脑室内注射链脲佐菌素（STZ）（3mg/kg）建立 AD 动物模型。然后，用 L-T4（10 和 100μg/kg）对大鼠进行 3 周治疗。
在 AD 动物中，气道对乙酰甲胆碱和卵清蛋白的反应性增加（p<0.05），白细胞（WBC）计数（p<0.05 至 p<0.01）、丙二醛（MDA）浓度（p<0.05）和炎症评分（p<0.01）升高，但超氧化物歧化酶（SOD）活性和总巯基含量（两者均为 p<0.05）降低。与 AD 组相比，AD 动物用 T4 治疗后气道对乙酰甲胆碱的反应性和 MDA 浓度降低。与对照组相比，用高剂量 T4 治疗的 AD 动物的 BALF 中总白细胞和某些差异白细胞以及炎症评分的支气管炎症显著恶化（p<0.05 至 p<0.001）。
阿尔茨海默病可能导致肺部炎症，用低剂量 T4 治疗可改善 MDA 水平和肺部炎症。
