Data/hora: 06/06/2024 05:57:49

Provedor de dados: | 56
País: | Brazil
Título: | Alternative complement pathway and factor B activities in rats with altered blood levels of thyroid hormone
Autores: | Bitencourt,C.S.; Duarte,C.G.; Azzolini,A.E.C.S.; Assis-Pandochi,A.I.
Data: | 2012-03-01
Ano: | 2012
Palavras-chave: | Thyroid hormone; Complement system; Alternative complement pathway; Factor B; T3; T4.
Resumo: | 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 &lt; 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.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012000300006
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X2012007500028
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.45 n.3 2012
Fonte: | info:eu-repo/semantics/openAccess