Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Av. do Café s/n, Ribeirão Preto, SP, Brazil.
Braz J Med Biol Res. 2012 Mar;45(3):216-21. doi: 10.1590/s0100-879x2012007500028. Epub 2012 Mar 1.
Evaluating the activity of the complement system under conditions of altered thyroid hormone levels might help elucidate the role of complement in triggering autoimmune processes. Here, we investigated alternative pathway (AP) activity in male Wistar rats (180 ± 10 g) after altering their thyroid hormone levels by treatment with triiodothyronine (T3), propylthiouracil (PTU) or thyroidectomy. T3 and thyroxine (T4) levels were determined by chemiluminescence assays. Hemolytic assays were performed to evaluate the lytic activity of the AP. Factor B activity was evaluated using factor B-deficient serum. An anti-human factor B antibody was used to measure factor B levels in serum by radial immunodiffusion. T3 measurements in thyroidectomized animals or animals treated with PTU demonstrated a significant reduction in hormone levels compared to control. The results showed a reduction in AP lytic activity in rats treated with increasing amounts of T3 (1, 10, or 50 µg). Factor B activity was also decreased in the sera of hyperthyroid rats treated with 1 to 50 µg T3. Additionally, treating rats with 25 µg T3 significantly increased factor B levels in their sera (P < 0.01). In contrast, increased factor B concentration and activity (32%) were observed in hypothyroid rats. We conclude that alterations in thyroid hormone levels affect the activity of the AP and factor B, which may in turn affect the roles of AP and factor B in antibody production.
评估甲状腺激素水平改变条件下补体系统的活性，可能有助于阐明补体在触发自身免疫过程中的作用。在这里，我们通过三碘甲状腺原氨酸（T3）、丙基硫氧嘧啶（PTU）或甲状腺切除术治疗改变雄性 Wistar 大鼠（180±10 g）的甲状腺激素水平后，研究了替代途径（AP）的活性。通过化学发光测定法测定 T3 和甲状腺素（T4）水平。进行溶血测定以评估 AP 的裂解活性。使用因子 B 缺乏血清评估因子 B 活性。使用抗人因子 B 抗体通过放射免疫扩散法测量血清中的因子 B 水平。与对照组相比，甲状腺切除动物或用 PTU 治疗的动物的 T3 测量值表明激素水平显著降低。结果表明，用递增剂量的 T3（1、10 或 50 µg）处理的大鼠中 AP 裂解活性降低。用 1 至 50 µg T3 处理的甲状腺功能亢进大鼠的因子 B 活性也降低。此外，用 25 µg T3 处理大鼠会显著增加其血清中的因子 B 水平（P<0.01）。相比之下，在甲状腺功能减退大鼠中观察到因子 B 浓度和活性（32%）增加。我们得出结论，甲状腺激素水平的改变会影响 AP 和因子 B 的活性，这反过来可能会影响 AP 和因子 B 在抗体产生中的作用。
