title: Baroreflex deficiency induces additional impairment of vagal tone, diastolic function and calcium handling proteins after myocardial infarction.
abstract: Baroreflex dysfunction has been considered an important mortality predictor after myocardial infarction (MI). However, the impact of baroreflex deficiency prior to MI on tonic autonomic control and cardiac function, and on the profile of proteins associated with intracellular calcium handling has not yet been studied. The aim of the present study was to analyze how the impairment of baroreflex induced by sinoaortic denervation (SAD) prior to MI in rats affects the tonic autonomic control, ventricular function and cardiomyocyte calcium handling proteins. After 15 days of following or SAD surgery, rats underwent MI. Echocardiographic, hemodynamic, autonomic and molecular evaluations were performed 90 days after MI. Baroreflex impairment led to additional damage on: left ventricular remodeling, diastolic function, vagal tonus and intrinsic heart rate after MI. The loss of vagal component of the arterial baroreflex and vagal tonus were correlated with changes in the cardiac proteins involved in intracellular calcium homeostasis. Furthermore, additional increase in sodium calcium exchanger expression levels was associated with impaired diastolic function in experimental animals. Our findings strongly suggest that previous arterial baroreflex deficiency may induce additional impairment of vagal tonus, which was associated with calcium handling proteins abnormalities, probably triggering ventricular diastolic dysfunction after MI in rats.
authors.affiliation: Federal University of Maranhao (UFMA) São Luis, Maranhão, Brazil.
authors.forename: Cristiano
authors.initials: C
authors.lastname: Mostarda
authors.affiliation: Human Movement Laboratory, Sao Judas Tadeu University (USJT) São Paulo, São Paulo, Brazil.
authors.forename: Bruno
authors.initials: B
authors.lastname: Rodrigues
authors.affiliation: Federal University of Sao Paulo (UNIFESP) Santos, São Paulo, Brazil.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Medeiros
authors.affiliation: Hypertension Unit, Heart Intitute (InCor), Medical School of University of Sao Paulo São Paulo, São Paulo, Brazil. Av. Dr. Eneas de Carvalho Aguiar, 44. CEP: 05403-000.
authors.forename: Edson D
authors.initials: ED
authors.lastname: Moreira
authors.affiliation: Hypertension Unit, Heart Intitute (InCor), Medical School of University of Sao Paulo São Paulo, São Paulo, Brazil. Av. Dr. Eneas de Carvalho Aguiar, 44. CEP: 05403-000.
authors.forename: Ivana C
authors.initials: IC
authors.lastname: Moraes-Silva
authors.affiliation: School of Physical Education and Sports, University of Sao Paulo São Paulo, São Paulo, Brazil.
authors.forename: Patricia C
authors.initials: PC
authors.lastname: Brum
authors.affiliation: Translational Physiology Laboratory, Nove de Julho University (UNINOVE) São Paulo, São Paulo, Brazil.
authors.forename: Katia De
authors.initials: KD
authors.lastname: Angelis
authors.affiliation: Hypertension Unit, Heart Intitute (InCor), Medical School of University of Sao Paulo São Paulo, São Paulo, Brazil. Av. Dr. Eneas de Carvalho Aguiar, 44. CEP: 05403-000.
authors.forename: Maria-Cláudia
authors.initials: MC
authors.lastname: Irigoyen
keywords: Arterial baroreflex; autonomic tone; calcium handling proteins; cardiac function; cardiac remodeling; myocardial infarction