title: Sexual dimorphism in autonomic changes and in the renin-angiotensin system in the hearts of mice subjected to thyroid hormone-induced cardiac hypertrophy.
abstract: Based on the relevance of the renin-angiotensin system and the ongoing controversy regarding the role of the sympathetic nervous system in thyroid hormone-induced cardiac hypertrophy, the aim of the present study was to establish whether the putative difference in the degree of cardiac hypertrophy exhibited by males and females might be related to differences in the sympathetic-vagal balance and/or in the cardiac renin-angiotensin system in mice of different genders. Male and female mice (n = 117) were given 0.1 mg kg(-1) of triiodothyronine or normal saline each day for 10 days consecutively. At the end of that period, study of the heart rate variability, spectral analysis and histopathological examination were performed to assess the sympathetic-vagal balance and the diameter of cardiomyocytes. The cardiac levels of angiotensin I and II were also measured. Treatment with triiodothyronine induced a greater degree of cardiac hypertrophy in male (~73%) than in female mice (~42%). This difference was attributed to greater modulation of the sympathetic nervous system and higher levels of angiotensin I and II in male than in female mice. Our data indicate that thyroid hormone-induced cardiac hypertrophy was more intense in male mice due to the synergic effect of the sympathetic nervous system and the cardiac renin-angiotensin system.
authors.affiliation: Multicenter Graduate Program in Physiological Sciences, Department of Physiological Sciences, Institute of Biology, Federal Rural University of Rio de Janeiro, Seropedica, Brazil.
authors.forename: Anderson Luiz Bezerra da
authors.initials: AL
authors.lastname: Silveira
authors.affiliation: Graduate Program in Veterinary Medicine, Department of Physiological Sciences, Institute of Biology, Federal Rural University of Rio de Janeiro, Seropedica, Brazil.
authors.forename: Manuela França
authors.initials: MF
authors.lastname: de Souza Miranda
authors.affiliation: Department of Physiology, School of Medicine, Ribeirao Preto USP - São Paulo, Brazil.
authors.forename: André Souza
authors.initials: AS
authors.lastname: Mecawi
authors.affiliation: Multicenter Graduate Program in Physiological Sciences, Department of Physiological Sciences, Institute of Biology, Federal Rural University of Rio de Janeiro, Seropedica, Brazil.
authors.forename: Roberto Laureano
authors.initials: RL
authors.lastname: Melo
authors.affiliation: Multicenter Graduate Program in Physiological Sciences, Department of Physiological Sciences, Institute of Biology, Federal Rural University of Rio de Janeiro, Seropedica, Brazil.
authors.forename: Michelle Porto
authors.initials: MP
authors.lastname: Marassi
authors.affiliation: Multicenter Graduate Program in Physiological Sciences, Department of Physiological Sciences, Institute of Biology, Federal Rural University of Rio de Janeiro, Seropedica, Brazil.
authors.forename: Alba Cenélia
authors.initials: AC
authors.lastname: Matos da Silva
authors.affiliation: Department of Physiology, School of Medicine, Ribeirao Preto USP - São Paulo, Brazil.
authors.forename: José
authors.initials: J
authors.lastname: Antunes-Rodrigues
authors.affiliation: Multicenter Graduate Program in Physiological Sciences, Department of Physiological Sciences, Institute of Biology, Federal Rural University of Rio de Janeiro, Seropedica, Brazil Graduate Program in Veterinary Medicine, Department of Physiological Sciences, Institute of Biology, Federal Rural University of Rio de Janeiro, Seropedica, Brazil olivares.el@gmail.com elopes@ufrrj.br.
authors.forename: Emerson Lopes
authors.initials: EL
authors.lastname: Olivares
mesh_terms: D000818:Animals; D001341:Autonomic Nervous System / Q000187:drug effects / Q000502:physiology; D006332:Cardiomegaly / Q000097:blood* / Q000139:chemically induced; D005260:Female; D008297:Male; D051379:Mice; D011897:Random Allocation; D012084:Renin-Angiotensin System / Q000187:drug effects / Q000502:physiology*; D012727:Sex Characteristics; D013963:Thyroid Hormones / Q000097:blood* / Q000633:toxicity
chemical_list: D013963:Thyroid Hormones