Role of Training and Detraining on Inflammatory and Metabolic Profile in Infarcted Rats: Influences of Cardiovascular Autonomic Nervous System

The aim of this study was to evaluate the effects of exercise training (ET, 50-70% of VO2max, 5 days/week) and detraining (DT) on inflammatory and metabolic profile after myocardial infarction (MI) in rats. Male Wistar rats were divided into control (C, n = 8), sedentary infarcted (SI, n = 9), trained infarcted (TI, n = 10; 3 months of ET), and detrained infarcted (DI, n = 11; 2 months of ET + 1 month of DT). After ET and DT protocols, ventricular function and inflammation, cardiovascular autonomic modulation (spectral analysis), and adipose tissue inflammation and lipolytic pathway were evaluated. ET after MI improved cardiac and vascular autonomic modulation, and these benefits were correlated with reduced inflammatory cytokines on the heart and adipose tissue. These positive changes were sustained even after 1 month of detraining. No expressive changes were observed in oxidative stress and lipolytic pathway in experimental groups. in conclusion, our results strongly suggest that the autonomic improvement promoted by ET, and maintained even after the detraining period, was associated with reduced inflammatory profile in the left ventricle and adipose tissue of rats subjected to MI. These data encourage enhancing cardiovascular autonomic function as a therapeutic strategy for the treatment of inflammatory process triggered by MI.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Sao Judas Tadeu Univ USJT, Human Movement Lab, BR-03166000 São Paulo, BrazilFed Univ São Paulo UNIFESP, Nutr Physiol Discipline, Dept Physiol, BR-04021001 São Paulo, BrazilUniv Extremo Catarinense UNESC, Lab Exercise Physiol & Biochem, BR-88806000 Criciuma, SC, BrazilUniv São Paulo, Sch Med, Heart Inst InCor, Hypertens Unit, BR-05403900 São Paulo, BrazilUniv São Paulo State UNESP, Dept Phys Educ, Immunometab Res Grp, BR-19060900 Presidente Prudente, SP, BrazilFed Univ São Paulo UNIFESP, Nutr Physiol Discipline, Dept Physiol, BR-04021001 São Paulo, BrazilFAPESP: 2013/14788-9FAPESP: 07/58942-0CNPq: CNPq: 563961/2010-4CNPq: 479076/2012-0CNPq: 457581/2013-1CAPES: CAPES: 074/2012CAPES: 095/2010Web of Scienc

The brief methylprednisolone administration is crucial to mitigate cardiac dysfunction after myocardial infarction

Acute myocardial infarction (AMI) is one of the major causes of heart failure and mortality. Glucocorticoids administration post-infarction has long been proposed, but it has shown conflicting results so far. This controversy may be associated with the glucocorticoid type and the period when it is administered. To elucidate these, the present aims to evaluate if the brief methylprednisolone acetate administration is determinant for heart adaptation after AMI. Male Wistar rats were divided into 3 groups: sham-operated (SHAM); infarcted (AMI); infarcted treated with methylprednisolone acetate (AMI+M). Immediately after surgery, the AMI+M group received a single dose of methylprednisolone acetate (40 mg/kg i.m.). After 56 days, the cardiac function was assessed and lungs, liver and heart were collected to determine rates of hypertrophy and congestion. Heart was used for oxidative stress and metalloproteinase activity analyses. Methylprednisolone acetate attenuated matrix metalloproteinase-2 activity, cardiac dilatation, and prevented the onset of pulmonary congestion, as well as avoided cardiac hypertrophy. Our data indicate that administration of methylprednisolone acetate shortly after AMI may be a therapeutic alternative for attenuation of detrimental ventricular remodeling

Measurement of left ventricular function in anaesthetised horses using transoesophageal doppler echocardiography

Studies were undertaken using transesophageal Doppler echocardiography to monitor left ventricular systolic function in anaesthetised horses. A 3.5 MHz transoesophageal probe was specifically developed in collaboration with Vingmed Sound for equine use. The indices of systolic function investigated were maximum acceleration of aortic blood flow (dv/dt^J, maximum blood flow velocity, (V^J, cardiac output (CO), left ventricular pre-ejection period (PEP) and left ventricular ejection time (ET).The feasibility of the technique was demonstrated in a group of 8 healthy Thoroughbred horses anaesthetised using a standard protocol. It was established that two dimensional transoesophageal echocardiography provided a reference view of the left ventricular outflow tract and aorta that consistently allowed high quality Doppler echocardiographic measurement of aortic blood flow velocity. The flow envelopes obtained were suitable for measurement of indices of left ventricular systolic function. The repeatability of the measured indices was similar to that of the maximum rate of rise of left ventricular pressure (LVdp/dtmax), obtained simultaneously by cardiac catheterisation.Cardiac output estimations made using transoesophageal Doppler echocardiography were compared with those obtained by thermodilution in the same group of horses under general anaesthesia. Cardiac output was altered by infusions of the sympathomimetic amine, dobutamine. Aortic velocity spectra obtained both by high pulse repetition frequency and continuous wave insonation modes were used to obtain the velocity time integral for calculation of cardiac output. The measurements derived from transoesophageal echocardiography agreed well with those obtained by thermodilution. Both correlation coefficients and limits of agreement between the two techniques were better than those obtained from similar studies in standing horses using transthoracic echocardiography.The sensitivity of the Doppler derived indices of left ventricular function to inotropic intervention was assessed in the final sequence of studies. As these indices are derived during the ejection period they are load dependent, so their response to changes in ventricular loading was also assessed and compared with the most commonly used index of myocardial contractility in horses, LVdp/dtmax. Three drugs were administered to the anaesthetised horses in a randomised sequence during three separate anaesthetic episodes. The drugs, dobutamine, dopamine and dopexamine were selected because of their relatively different effects on afterload, preload and contractility. Maximum acceleration of aortic blood flow was as sensitive to the changes in ventricular performance as LVdp/dtmax. Maximum aortic blood velocity showed the same qualitative response to infusion of the drugs but the changes were quantitatively less than in dv/dtmax and LVdp/dtmax. The systolic time intervals, PEP and ET, were also responsive to drug infusion; pre-ejection period shortened with each drug, whilst ET increased after dopamine and dopexamine, but was reduced by dobutamine.These studies have shown that dv/dtmax is as sensitive as the invasive index LVdp/dtmax for detecting changes in left ventricular performance. In addition dv/dtmax and Vmax appear to be no more affected by changes in ventricular loading conditions than the isovolumic index LVdp/dtmax. It is concluded that transoesophageal Doppler echocardiography provides a minimally invasive technique for assessment of left ventricular systolic function in anaesthetised horses

Aerospace Medicine and Biology: A continuing bibliography with indexes, supplement 172

This bibliography lists 132 reports, articles, and other documents introduced into the NASA scientific and technical information system in September 1977