Baroreflex function in conscious rats submitted to iron overload.
Autor(a) principal: | |
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Data de Publicação: | 2005 |
Outros Autores: | , , , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UFOP |
Texto Completo: | http://www.repositorio.ufop.br/handle/123456789/1813 |
Resumo: | Our hypothesis is that iron accumulated in tissue, rather than in serum, may compromise cardiovascular control. Male Fischer 344 rats weighing 180 to 220 g were divided into 2 groups. In the serum iron overload group (SIO, N = 12), 20 mg elemental iron was injected ip daily for 7 days. In the tissue iron overload group (TIO, N = 19), a smaller amount of elemental iron was injected (10 mg, daily) for 5 days followed by a resting period of 7 days. Reflex heart rate responses were elicited by iv injections of either phenylephrine (0.5 to 5.0 µg/kg) or sodium nitroprusside (1.0 to 10.0 µg/kg). Baroreflex curves were determined and fitted to sigmoidal equations and the baroreflex gain coefficient was evaluated. To evaluate the role of other than a direct effect of iron on tissue, acute treatment with the iron chelator deferoxamine (20 mg/kg, iv) was performed on the TIO group and the baroreflex was re-evaluated. At the end of the experiments, evaluation of iron levels in serum confirmed a pronounced overload for the SIO group (30-fold), in contrast to the TIO group (2-fold). Tissue levels of iron, however, were higher in the TIO group. The SIO protocol did not produce significant alterations in the baroreflex curve response, while the TIO protocol produced a nearly 2-fold increase in baroreflex gain (-4.34 ± 0.74 and -7.93 ± 1.08 bpm/mmHg, respectively). The TIO protocol animals treated with deferoxamine returned to sham levels of baroreflex gain (-3.7 ± 0.3 sham vs -3.6 ± 0.2 bpm/mmHg) 30 min after the injection. Our results indicate an effect of tissue iron overload on the enhancement of baroreflex sensitivity. |
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Baroreflex function in conscious rats submitted to iron overload.Blood pressureDeferoxamineIron dextranBaroreflexIron overloadHeart rateOur hypothesis is that iron accumulated in tissue, rather than in serum, may compromise cardiovascular control. Male Fischer 344 rats weighing 180 to 220 g were divided into 2 groups. In the serum iron overload group (SIO, N = 12), 20 mg elemental iron was injected ip daily for 7 days. In the tissue iron overload group (TIO, N = 19), a smaller amount of elemental iron was injected (10 mg, daily) for 5 days followed by a resting period of 7 days. Reflex heart rate responses were elicited by iv injections of either phenylephrine (0.5 to 5.0 µg/kg) or sodium nitroprusside (1.0 to 10.0 µg/kg). Baroreflex curves were determined and fitted to sigmoidal equations and the baroreflex gain coefficient was evaluated. To evaluate the role of other than a direct effect of iron on tissue, acute treatment with the iron chelator deferoxamine (20 mg/kg, iv) was performed on the TIO group and the baroreflex was re-evaluated. At the end of the experiments, evaluation of iron levels in serum confirmed a pronounced overload for the SIO group (30-fold), in contrast to the TIO group (2-fold). Tissue levels of iron, however, were higher in the TIO group. The SIO protocol did not produce significant alterations in the baroreflex curve response, while the TIO protocol produced a nearly 2-fold increase in baroreflex gain (-4.34 ± 0.74 and -7.93 ± 1.08 bpm/mmHg, respectively). The TIO protocol animals treated with deferoxamine returned to sham levels of baroreflex gain (-3.7 ± 0.3 sham vs -3.6 ± 0.2 bpm/mmHg) 30 min after the injection. Our results indicate an effect of tissue iron overload on the enhancement of baroreflex sensitivity.2012-11-26T13:29:38Z2012-11-26T13:29:38Z2005info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfCARDOSO, L. M. et al. Baroreflex function in conscious rats submitted to iron overload. Brazilian Journal of Medical and Biological Research, v. 38, n. 2, p. 205-214, fev. 2005. Disponível em: <http://www.scielo.br/pdf/bjmbr/v38n2/5462.pdf>. Acesso em: 26 nov. 2012.1414431Xhttp://www.repositorio.ufop.br/handle/123456789/1813Todo o conteúdo do periódico Brazilian Journal of Medical and Biological Research, exceto onde identificado, está licenciado sob uma licença Creative Commons 4.0 que permite copiar, distribuir e transmitir o trabalho em qualquer suporte ou formato desde que sejam citados o autor e o licenciante. Fonte: Brazilian Journal of Medical and Biological Research <http://www.scielo.br/scielo.php?script=sci_serial&pid=0100-879X&lng=en&nrm=iso>. Acesso em: 20 out. 2016.info:eu-repo/semantics/openAccessCardoso, Leonardo MáximoPedrosa, Maria LúciaSilva, Marcelo EustáquioMoraes, Márcio Flávio DutraColombari, EduardoChianca Júnior, Deoclécio Alvesengreponame:Repositório Institucional da UFOPinstname:Universidade Federal de Ouro Preto (UFOP)instacron:UFOP2019-03-13T17:09:34Zoai:repositorio.ufop.br:123456789/1813Repositório InstitucionalPUBhttp://www.repositorio.ufop.br/oai/requestrepositorio@ufop.edu.bropendoar:32332019-03-13T17:09:34Repositório Institucional da UFOP - Universidade Federal de Ouro Preto (UFOP)false |
dc.title.none.fl_str_mv |
Baroreflex function in conscious rats submitted to iron overload. |
title |
Baroreflex function in conscious rats submitted to iron overload. |
spellingShingle |
Baroreflex function in conscious rats submitted to iron overload. Cardoso, Leonardo Máximo Blood pressure Deferoxamine Iron dextran Baroreflex Iron overload Heart rate |
title_short |
Baroreflex function in conscious rats submitted to iron overload. |
title_full |
Baroreflex function in conscious rats submitted to iron overload. |
title_fullStr |
Baroreflex function in conscious rats submitted to iron overload. |
title_full_unstemmed |
Baroreflex function in conscious rats submitted to iron overload. |
title_sort |
Baroreflex function in conscious rats submitted to iron overload. |
author |
Cardoso, Leonardo Máximo |
author_facet |
Cardoso, Leonardo Máximo Pedrosa, Maria Lúcia Silva, Marcelo Eustáquio Moraes, Márcio Flávio Dutra Colombari, Eduardo Chianca Júnior, Deoclécio Alves |
author_role |
author |
author2 |
Pedrosa, Maria Lúcia Silva, Marcelo Eustáquio Moraes, Márcio Flávio Dutra Colombari, Eduardo Chianca Júnior, Deoclécio Alves |
author2_role |
author author author author author |
dc.contributor.author.fl_str_mv |
Cardoso, Leonardo Máximo Pedrosa, Maria Lúcia Silva, Marcelo Eustáquio Moraes, Márcio Flávio Dutra Colombari, Eduardo Chianca Júnior, Deoclécio Alves |
dc.subject.por.fl_str_mv |
Blood pressure Deferoxamine Iron dextran Baroreflex Iron overload Heart rate |
topic |
Blood pressure Deferoxamine Iron dextran Baroreflex Iron overload Heart rate |
description |
Our hypothesis is that iron accumulated in tissue, rather than in serum, may compromise cardiovascular control. Male Fischer 344 rats weighing 180 to 220 g were divided into 2 groups. In the serum iron overload group (SIO, N = 12), 20 mg elemental iron was injected ip daily for 7 days. In the tissue iron overload group (TIO, N = 19), a smaller amount of elemental iron was injected (10 mg, daily) for 5 days followed by a resting period of 7 days. Reflex heart rate responses were elicited by iv injections of either phenylephrine (0.5 to 5.0 µg/kg) or sodium nitroprusside (1.0 to 10.0 µg/kg). Baroreflex curves were determined and fitted to sigmoidal equations and the baroreflex gain coefficient was evaluated. To evaluate the role of other than a direct effect of iron on tissue, acute treatment with the iron chelator deferoxamine (20 mg/kg, iv) was performed on the TIO group and the baroreflex was re-evaluated. At the end of the experiments, evaluation of iron levels in serum confirmed a pronounced overload for the SIO group (30-fold), in contrast to the TIO group (2-fold). Tissue levels of iron, however, were higher in the TIO group. The SIO protocol did not produce significant alterations in the baroreflex curve response, while the TIO protocol produced a nearly 2-fold increase in baroreflex gain (-4.34 ± 0.74 and -7.93 ± 1.08 bpm/mmHg, respectively). The TIO protocol animals treated with deferoxamine returned to sham levels of baroreflex gain (-3.7 ± 0.3 sham vs -3.6 ± 0.2 bpm/mmHg) 30 min after the injection. Our results indicate an effect of tissue iron overload on the enhancement of baroreflex sensitivity. |
publishDate |
2005 |
dc.date.none.fl_str_mv |
2005 2012-11-26T13:29:38Z 2012-11-26T13:29:38Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
CARDOSO, L. M. et al. Baroreflex function in conscious rats submitted to iron overload. Brazilian Journal of Medical and Biological Research, v. 38, n. 2, p. 205-214, fev. 2005. Disponível em: <http://www.scielo.br/pdf/bjmbr/v38n2/5462.pdf>. Acesso em: 26 nov. 2012. 1414431X http://www.repositorio.ufop.br/handle/123456789/1813 |
identifier_str_mv |
CARDOSO, L. M. et al. Baroreflex function in conscious rats submitted to iron overload. Brazilian Journal of Medical and Biological Research, v. 38, n. 2, p. 205-214, fev. 2005. Disponível em: <http://www.scielo.br/pdf/bjmbr/v38n2/5462.pdf>. Acesso em: 26 nov. 2012. 1414431X |
url |
http://www.repositorio.ufop.br/handle/123456789/1813 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.source.none.fl_str_mv |
reponame:Repositório Institucional da UFOP instname:Universidade Federal de Ouro Preto (UFOP) instacron:UFOP |
instname_str |
Universidade Federal de Ouro Preto (UFOP) |
instacron_str |
UFOP |
institution |
UFOP |
reponame_str |
Repositório Institucional da UFOP |
collection |
Repositório Institucional da UFOP |
repository.name.fl_str_mv |
Repositório Institucional da UFOP - Universidade Federal de Ouro Preto (UFOP) |
repository.mail.fl_str_mv |
repositorio@ufop.edu.br |
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1813002854895452160 |