Alternative complement pathway and factor B activities in rats with altered blood levels of thyroid hormone.
Braz J Med Biol Res
; 45(3): 216-21, 2012 Mar.
Article
en En
| MEDLINE
| ID: mdl-22370704
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.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Propiltiouracilo
/
Antitiroideos
/
Tiroxina
/
Triyodotironina
/
Factor B del Complemento
/
Vía Alternativa del Complemento
Límite:
Animals
Idioma:
En
Revista:
Braz J Med Biol Res
Año:
2012
Tipo del documento:
Article
País de afiliación:
Brasil
Pais de publicación:
Brasil