title: Effects of autonomic balance and fluid and electrolyte changes on cardiac function in infarcted rats: A serial study of sexual dimorphism.
abstract: Premenopausal women are known to show lower incidence of cardiovascular disease than men. During myocardial infarction (MI), homeostatic responses are activated, including the sympathetic autonomic nervous system and the rennin-angiotensin-aldosterone system, which is related to the fluid and electrolyte balance, both aiming to maintain cardiac output. This study sought to perform a serial evaluation of sexual dimorphism in cardiac autonomic control and fluid and electrolyte balance during the development of MI-induced heart failure in rats. Experimental MI was induced in male (M) and female (F) adult (7-9 weeks of age) Wistar rats. The animals were placed in metabolic cages to assess fluid intake and urine volume 1 and 4 weeks after inducing MI (male myocardial infarction (MMI) and female myocardial infarction (FMI) groups). They subsequently underwent echocardiographic evaluation and spectral analysis of heart rate variability. After completing each protocol, the animals were killed for postmortem evaluation and histology. The MMI group showed earlier and more intense cardiac morphological and functional changes than the FMI group, although the extent of MI did not differ between groups (P > 0.05). The MMI group showed higher sympathetic modulation and sodium and water retention than the FMI group (P < 0.05), which may partly explain both the echocardiographic and pathological findings. Females subjected to infarction seem to show attenuation of sympathetic modulation, more favourable fluid and electrolyte balances, and better preserved cardiac function compared to males subjected to the same infarction model.
authors.affiliation: Multicentre Graduate Program in Physiological Sciences, Department of Physiological Sciences, Institute of Biological and Health Sciences, Federal Rural University of Rio de Janeiro, Seropédica, Brazil.
authors.forename: N S
authors.initials: NS
authors.lastname: Souza
authors.affiliation: Graduate Program in Physiological Sciences, Department of Physiological Sciences, Institute of Biological and Health Sciences, Federal Rural University of Rio de Janeiro, Seropédica, Brazil.
authors.forename: R C
authors.initials: RC
authors.lastname: Dos-Santos
authors.affiliation: Multicentre Graduate Program in Physiological Sciences, Department of Physiological Sciences, Institute of Biological and Health Sciences, Federal Rural University of Rio de Janeiro, Seropédica, Brazil.
authors.forename: Anderson Luiz Bezerra da
authors.initials: AL
authors.lastname: Silveira
authors.affiliation: Multicentre Graduate Program in Physiological Sciences, Department of Physiological Sciences, Institute of Biological and Health Sciences, Federal Rural University of Rio de Janeiro, Seropédica, Brazil.
authors.forename: Sonoda-Côrtes
authors.initials: SC
authors.lastname: R
authors.affiliation: Therapy and Cellular and Molecular Physiology Laboratory, Centre for Biological and Health Sciences, West Zone State University Centre, Rio de Janeiro, Brazil.
authors.forename: Michel Alexandre Villani
authors.initials: MA
authors.lastname: Gantus
authors.affiliation: Graduate Program in Physiological Sciences, Department of Physiological Sciences, Institute of Biological and Health Sciences, Federal Rural University of Rio de Janeiro, Seropédica, Brazil.|Therapy and Cellular and Molecular Physiology Laboratory, Centre for Biological and Health Sciences, West Zone State University Centre, Rio de Janeiro, Brazil.
authors.forename: F S
authors.initials: FS
authors.lastname: Fortes
authors.affiliation: Multicentre Graduate Program in Physiological Sciences, Department of Physiological Sciences, Institute of Biological and Health Sciences, Federal Rural University of Rio de Janeiro, Seropédica, Brazil.|Graduate Program in Physiological Sciences, Department of Physiological Sciences, Institute of Biological and Health Sciences, Federal Rural University of Rio de Janeiro, Seropédica, Brazil.
authors.forename: Emerson Lopes
authors.initials: EL
authors.lastname: Olivares
mesh_terms: D000818:Animals; D001341:Autonomic Nervous System / Q000503:physiopathology*; D001826:Body Fluids / Q000378:metabolism*; D018450:Disease Progression; D004573:Electrolytes / Q000378:metabolism*; D005260:Female; D006321:Heart / Q000503:physiopathology*; D008297:Male; D009203:Myocardial Infarction / Q000378:metabolism / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar; D012727:Sex Characteristics
chemical_list: D004573:Electrolytes
keywords: fluid and electrolyte balance; myocardial infarction; sympathetic nervous system