Baroreflex function in conscious rats submitted to iron overload.

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MetadadosDescriçãoIdioma
Autor(es): dc.creatorCardoso, Leonardo Máximo-
Autor(es): dc.creatorPedrosa, Maria Lúcia-
Autor(es): dc.creatorSilva, Marcelo Eustáquio-
Autor(es): dc.creatorMoraes, Márcio Flávio Dutra-
Autor(es): dc.creatorColombari, Eduardo-
Autor(es): dc.creatorChianca Júnior, Deoclécio Alves-
Data de aceite: dc.date.accessioned2019-11-06T13:31:41Z-
Data de disponibilização: dc.date.available2019-11-06T13:31:41Z-
Data de envio: dc.date.issued2015-01-21-
Data de envio: dc.date.issued2015-01-21-
Data de envio: dc.date.issued2005-
Fonte completa do material: dc.identifierhttp://www.repositorio.ufop.br/handle/123456789/4300-
Fonte: dc.identifier.urihttp://educapes.capes.gov.br/handle/capes/557279-
Descrição: dc.descriptionOur 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 reevaluated. 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.-
Idioma: dc.languageen-
Direitos: dc.rightsNo permission is required from the authors or the publishers download, reuse, reprint, modify, distribute, and/or copy articles published in the BJMBR, as long as the original authors and source are cited. Fonte: Brazilian Journal of Medical and Biological Research <http://www.bjournal.com.br/index.php?option=com_content&view=article&id=185&Itemid=139>. Acesso em: 21 jan. 2014.-
Palavras-chave: dc.subjectBaroreflex-
Palavras-chave: dc.subjectIron overload-
Palavras-chave: dc.subjectHeart rate-
Palavras-chave: dc.subjectBlood pressure-
Palavras-chave: dc.subjectIron dextran-
Título: dc.titleBaroreflex function in conscious rats submitted to iron overload.-
Aparece nas coleções:Repositório Institucional - UFOP

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