Alternative complement pathway and factor B activities in rats with altered blood levels of thyroid hormone

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 ho...

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Main Authors: C.S. Bitencourt, C.G. Duarte, A.E.C.S. Azzolini, A.I. Assis-Pandochi
Format: Article
Language:English
Published: Associação Brasileira de Divulgação Científica 2012-03-01
Series:Brazilian Journal of Medical and Biological Research
Subjects:
Online Access:http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012000300006&lng=en&tlng=en
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author C.S. Bitencourt
C.G. Duarte
A.E.C.S. Azzolini
A.I. Assis-Pandochi
author_facet C.S. Bitencourt
C.G. Duarte
A.E.C.S. Azzolini
A.I. Assis-Pandochi
author_sort C.S. Bitencourt
collection DOAJ
description 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.
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spelling doaj.art-86161d048df84bc28f8a550511f65d042022-12-21T22:31:28ZengAssociação Brasileira de Divulgação CientíficaBrazilian Journal of Medical and Biological Research1414-431X2012-03-01453216221S0100-879X2012000300006Alternative complement pathway and factor B activities in rats with altered blood levels of thyroid hormoneC.S. Bitencourt0C.G. Duarte1A.E.C.S. Azzolini2A.I. Assis-Pandochi3Universidade de São PauloUniversidade de São PauloUniversidade de São PauloUniversidade de São PauloEvaluating 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.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012000300006&lng=en&tlng=enThyroid hormoneComplement systemAlternative complement pathwayFactor BT3T4
spellingShingle C.S. Bitencourt
C.G. Duarte
A.E.C.S. Azzolini
A.I. Assis-Pandochi
Alternative complement pathway and factor B activities in rats with altered blood levels of thyroid hormone
Brazilian Journal of Medical and Biological Research
Thyroid hormone
Complement system
Alternative complement pathway
Factor B
T3
T4
title Alternative complement pathway and factor B activities in rats with altered blood levels of thyroid hormone
title_full Alternative complement pathway and factor B activities in rats with altered blood levels of thyroid hormone
title_fullStr Alternative complement pathway and factor B activities in rats with altered blood levels of thyroid hormone
title_full_unstemmed Alternative complement pathway and factor B activities in rats with altered blood levels of thyroid hormone
title_short Alternative complement pathway and factor B activities in rats with altered blood levels of thyroid hormone
title_sort alternative complement pathway and factor b activities in rats with altered blood levels of thyroid hormone
topic Thyroid hormone
Complement system
Alternative complement pathway
Factor B
T3
T4
url http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012000300006&lng=en&tlng=en
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