McAllister R M, Delp M D, Laughlin M H
Department of Veterinary Biomedical Sciences, University of Missouri, Columbia 62511, USA.
Can J Appl Physiol. 1997 Feb;22(1):1-10. doi: 10.1139/h97-001.
Hypothyroidism is a common thyroid disease characterized by exercise intolerance. Both exercise capacity and endurance are compromised in the hypothyroid state. Studies involving rats performing treadmill running have shown that blood flows during exercise to high oxidative, extensor-type muscles are lower in hypothyroid rats compared with those in euthyroid rats. Abnormal cardiac and vascular function appear to contribute to this hypoperfusion. Experiments involving isolated arterial vessel segments have demonstrated that potential for constriction is normal in vessels from hypothyroid animals; however, reduced vasodilator potential is associated with hypothyroidism. Dysfunction of both endothelium and vascular smooth muscle appear to contribute to blunted potential for vasodilation. Altered ability to generate vasodilatory substances and/or changes in responses to these vasodilators may account for vascular dysfunction. It appears that impaired vascular function interacts with other factors such as poor myocardial function and changes in energy metabolism to compromise exercise tolerance.
甲状腺功能减退症是一种常见的甲状腺疾病，其特征为运动不耐受。在甲状腺功能减退状态下，运动能力和耐力均会受到损害。涉及大鼠跑步机跑步的研究表明，与甲状腺功能正常的大鼠相比，甲状腺功能减退的大鼠在运动期间流向高氧化、伸肌型肌肉的血流量更低。心脏和血管功能异常似乎是导致这种灌注不足的原因。涉及离体动脉血管段的实验表明，甲状腺功能减退动物的血管收缩潜力正常；然而，血管舒张潜力降低与甲状腺功能减退症有关。内皮和血管平滑肌功能障碍似乎都导致了血管舒张潜力减弱。生成血管舒张物质的能力改变和/或对这些血管舒张剂反应的变化可能是血管功能障碍的原因。血管功能受损似乎与其他因素相互作用，如心肌功能不佳和能量代谢变化，从而损害运动耐量。
