Fasting/Refeeding Cycles Prevent Myocardial Dysfunction and Morphology Damage in the Spontaneously Hypertensive Rats.

Background: Caloric restriction is known to impair the cardiac function and morphology in hypertrophied hearts of spontaneously hypertensive rats (SHR); however, the influence of fasting/refeeding (RF) is unknown.

Objective: To investigate the fasting/refeeding approach on myocardial remodeling and function. In addition, the current study was designed to bring information regarding the mechanisms underlying the participation of Ca2+ handling and b-adrenergic system.

Myocardial contractility impairment with racemic bupivacaine, non-racemic bupivacaine and ropivacaine. A comparative study.

Purpose: To study racemic bupivacaine, non-racemic bupivacaine and ropivacaine on myocardial contractility.

Methods: Isolated Wistar papillary muscles were submitted to 50 and 100 mM racemic bupivacaine (B50 and B100), non-racemic bupivacaine (NR50 and NR100) and ropivacaine (R50 and R100) intoxication. Isometric contraction data were obtained in basal condition (0.

A comparative study of myocardial function and morphology during fasting/refeeding and food restriction in rats.

Background: This study compared the influence of fasting/refeeding cycles and food restriction on rat myocardial performance and morphology.

Methods: Sixty-day-old male Wistar rats were submitted to food ad libitum (C), 50% food restriction (R50), and fasting/refeeding cycles (RF) for 12 weeks. Myocardial function was evaluated under baseline conditions and after progressive increase in calcium and isoproterenol.

Food restriction promotes downregulation of myocardial L-type Ca2+ channels.

Food restriction (FR) has been shown to impair myocardial performance. However, the mechanisms behind these changes in myocardial function due to FR remain unknown. Since myocardial L-type Ca2+ channels may contribute to the cardiac dysfunction, we examined the influence of FR on L-type Ca2+ channels.

Influences of rich in saturated and unsaturated fatty acids diets in rat myocardium.

Objectives: To study the influence of saturated (SFA) and unsaturated fatty acid (UFA) rich diets on mechanical function, morphology and oxidative stress in rat myocardium.

Methods: Male, 60-day-old Wistar rats were fed a control (n=8), a SFA (n=8), or a UFA-rich diet (n=8) for sixty days. Mechanical function was studied in isolated left ventricle papillary muscle under isometric and isotonic contractions, in basal conditions (1.