Li Y, Chen H, Tan J, Wang X, Liang H, Sun X
Affiliated Hospital of Zunyi Medical School, Zunyi 563003, China.
Eur J Clin Invest. 1998 Dec;28(12):1050-4. doi: 10.1046/j.1365-2362.1998.00381.x.
Patients with hyperthyroidism have increased plasma levels of von Willebrand factor (vWF). Changes in tissue plasminogen activator (t-PA) and plasminogen activator inhibitor (PAI-1), another two endothelium-derived proteins and modulators of blood fibrinolytic activity, have not been reported in hyperthyroidism.
The release of t-PA by vascular endothelial cells after venous occlusion, basal blood concentrations of t-PA, PAI-1 and vWF were studied in 33 patients with hyperthyroidism, with most of them followed up 30 days after iodine radiotherapy.
Compared with control subjects, both the basal t-PA levels in plasma and the increase in t-PA levels with venous occlusion were significantly decreased in patients (P < 0.001), whereas plasma PAI-1 and vWF levels were increased greatly (P < 0.001). At follow-up, patients with normal plasma free thyroxine (T4) and total tri-iodothyronine (T3) showed similar plasma levels of t-PA, PAI-1, vWF and release of t-PA from endothelial cells as the control subjects (P > 0.05). In those with persistent elevated T4 or T3 levels, however, the basal plasma t-PA level and the released t-PA from endothelial cells during venous occlusion were significantly lower than in the control subjects (P < 0.001 and P < 0.005), and blood concentrations of PAI-1 and vWF did not return to the normal range (P < 0.001 and P < 0.001). In all patients, serum thyroid hormone concentrations were inversely correlated with basal plasma t-PA (T4: r = -0.549, P < 0. 001; T3: r = -0.463, P < 0.001) and released t-PA by endothelial cells (T4: r = -0.505, P < 0.001; T3: r = -0.450, P < 0.001) but strongly correlated with plasma PAI-1 (T4: r = 0.613, P < 0.001; T3: r = 0.577, P < 0.001) and vWF (T4: r = 0.457, P < 0.001; T3: r = 0. 564, P < 0.001).
Hyperthyroid patients may experience vascular endothelial dysfunction and reduced fibrinolytic activity in blood.
甲状腺功能亢进患者血浆中血管性血友病因子（vWF）水平升高。组织纤溶酶原激活物（t-PA）和纤溶酶原激活物抑制剂（PAI-1）是另外两种内皮细胞衍生的蛋白，也是血液纤溶活性的调节因子，甲状腺功能亢进患者中这两种蛋白的变化尚未见报道。
对33例甲状腺功能亢进患者进行研究，观察静脉阻塞后血管内皮细胞释放t-PA的情况，以及t-PA、PAI-1和vWF的基础血浓度，其中大多数患者在碘放疗后随访30天。
与对照组相比，患者血浆中基础t-PA水平以及静脉阻塞时t-PA水平的升高均显著降低（P<0.001），而血浆PAI-1和vWF水平大幅升高（P<0.001）。随访时，血浆游离甲状腺素（T4）和总三碘甲状腺原氨酸（T3）正常的患者，其血浆t-PA、PAI-1、vWF水平以及内皮细胞释放t-PA的情况与对照组相似（P>0.05）。然而，T4或T3水平持续升高的患者，其基础血浆t-PA水平以及静脉阻塞时内皮细胞释放的t-PA显著低于对照组（P<0.001和P<0.005），PAI-1和vWF的血浓度未恢复到正常范围（P<0.001和P<0.001）。在所有患者中，血清甲状腺激素浓度与基础血浆t-PA（T4：r=-0.549，P<0.001；T3：r=-0.463，P<0.001）和内皮细胞释放的t-PA（T4：r=-0.505，P<0.001；T3：r=-0.450，P<0.001）呈负相关，但与血浆PAI-1（T4：r=0.613，P<0.001；T3：r=0.577，P<0.001）和vWF（T4：r=0.457，P<0.001；T3：r=0.564，P<0.001）呈强正相关。
甲状腺功能亢进患者可能存在血管内皮功能障碍以及血液纤溶活性降低。
