Data/hora: 03/06/2024 15:11:53

Provedor de dados: 	Brazilian Journal of Medical and Biological Research	
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