Swimming training attenuates the decrease of calcium responsiveness in female infarcted rats.

To evaluate the influence of swimming training on calcium responsiveness of the myocardium of rats with different infarction sizes (MI). female Wistar rats, sedentary sham (SS = 14), sedentary moderate MI (SMI = 8) and sedentary large MI (SLI = 10) were compared to trained sham (TS = 16), trained moderate MI (TMI = 9) and trained large MI (TLI = 10). After 4 weeks of MI, the animals swam for 60 min/day, 5 days/week, for additional 8 weeks.

Paradoxical Sleep Deprivation Causes Cardiac Dysfunction and the Impairment Is Attenuated by Resistance Training.

Background: Paradoxical sleep deprivation activates the sympathetic nervous system and the hypothalamus-pituitary-adrenal axis, subsequently interfering with the cardiovascular system. The beneficial effects of resistance training are related to hemodynamic, metabolic and hormonal homeostasis. We hypothesized that resistance training can prevent the cardiac remodeling and dysfunction caused by paradoxical sleep deprivation.

Are there gender differences in left ventricular remodeling after myocardial infarction in rats?

Objective: An unclear issue is whether gender may influence at cardiac remodeling after myocardial infarction (MI). We evaluated left ventricle remodeling in female and male rats post-MI.

Methods: Rats were submitted to anterior descending coronary occlusion.

Cardiac implications after myocardial infarction in rats previously undergoing physical exercise.

Background: Few studies have analyzed the cardiac effects of exercise prior to coronary occlusion.

Objective: To evaluate the effects of myocardial infarction in rats undergoing physical exercise.

Methods: Female rats underwent swimming exercise or were kept sedentary for eight weeks and were randomized to coronary occlusion or sham surgery, in one of the following four groups: Sedentary (S), exercise (E), Sedentary myocardial infarction (SMI) and Exercise myocardial infarction (EMI).

Myocardial remodeling after large infarcts in rat converts post rest-potentiation in force decay.

Background: Post-rest contraction (PRC) of cardiac muscle provides indirect information about the intracellular calcium handling.

Objective: Our aim was to study the behavior of PRC, and its underlying mechanisms, in rats with myocardial infarction.

Methods: Six weeks after coronary occlusion, the contractility of papillary muscles (PM) obtained from sham-operated (C, n=17), moderate infarcted (MMI, n=10) and large infarcted (LMI, n=14) rats was evaluated, following rest intervals of 10 to 60 seconds before and after incubation with lithium chloride (Li(+)) substituting sodium chloride or ryanodine (Ry).

Swimming training attenuates remodeling, contractile dysfunction and congestive heart failure in rats with moderate and large myocardial infarctions.

1. The aim of the present study was to evaluate the effect of swimming on myocardial remodelling after myocardial infarction (MI) in female rats induced by coronary occlusion, which was not performed in sham rats. 2.