Effect of Adaptation to Graduated Physical Exercises on the Function of the Rat Myocardium

Abstract

On isolated hearts obtained from control rats and rats subjected to regular physical exercises (forced swimming) during 6 weeks, we studied the contractile activity of the heart, resistance of the myocardium to ischemia/reperfusion-induced injuries, as well as the dependence of the developed and end-diastolic pressures in the aortic ventricle (AV) on the strain of the myocardium (by means of a dosed increase in the volume of a polyethylene reservoir inserted into the ventricle). It was demonstrated that adaptation to regular graduated physical exercises exerts a positive effect on the functional state of the AV myocardium and its contractile function. This was manifested in intensification of the contractile activity of the myocardium, a decrease in its oxygen "job cost," and an increase in the resistance to injuries induced by ischemia-reperfusion. In addition, regular physical trainings led to an increase in the resistance of the AV myocardium to the strain. In trained rats, the plateau of the Frank-Starling plot was significantly greater than that in control animals, while the rigidity of the AV myocardium was significantly lower.

Physiological and biochemical indicators of the organism after normobaric hypoxic training in combination with a protein product supplementation

“…A decrease in the coagulation activity of blood and lymph and its anticoagulation properties is a positive phenomenon, especially since the pH does not change. The most important and rapid adaptive effect of hypoxia is the expansion of capillaries in the brain, heart and lungs, which runs in parallel with increased blood circulation, and therefore the minute volume of blood circulation increases [5]. Hypoxia is a condition that occurs due to a lack of oxygen in the body's tissues.…”