Preconditioning of rat heart ischemia reperfusion injury with different types of training processes

[M. S. Glišić]

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Podaci o uticaju različitih tipova trenažnih aktivnosti na funkcionalni oporavak srca nakon ishemijsko/reperfuzionog oštećenja su još uvek jako neusaglašeni. Dodatni problem prestavlja činjenica, da i dalje nije poznato koji tip treninga i njegovog intenziteta (aerobni ili anaerobni) ostvaruje najbolje rezultate u prekondicioniranju miokarda. Cilj ove studije je ispitivanje efekata prekondicioniranja vežbanjem na animalnom modelu ishemijsko/reperfuzione povrede (I / R) miokarda pacova odnosno utvrđivanje uticaja različitih tipova trenažnih procesa na I / R, kao i uloge oksidacionog stresa u dobijenim efektima. Studija je sprovedena na 40 pacova razvrstanih u jednu kontrolnu (sedenterni pacovi) i četiri eksperimentalne grupe. Pacovi iz eksperimentalnih grupa su bili podvrgnuti trenažnom protokolu prekondicionoranja trčanjem i plivanjem (u aerobnoj i anaerobnoj formi). Nakon trenažnih protkola životinje su žrtvovane, a izolovana srca perfundovana metodom retrogradne perfuzije po Langendorff-u pri konstantnom koronarnom perfuzionom pritisku od 70 smH2O. Nakon stabilizacije, srca su bila podvrgnuta globalnoj ishemiji u trajanju od 20 minuta, a potom i reperfuziji u trajanju od 30 minuta. Vrednosti koronarnog protoka su bile određivane floumetrijski, a parametri funkcije leve komore (dp/dt max, dp/dt min, SLVP, DLVP i HR) su kontinuirano praćeni. U uzorcima koronarnog venskog efluenta, kao i u krvi pacova spektrofotometrijskim metodama su određivani parametri oksidacionog stresa. Standardnom histološkom analizom su utvrđivane promene na srcu i kvadricepsu. Obe vrste treninga samo pri aerobnim intenzitetima dovele su do efikasnijeg oporavka većine kardiodinamskih pokazatelja, dok u anaerobnim zonama nisu uspele da ostvare bolje efekte u odnosu na sedaterne pacove. Osim toga, obe vrste treninga bile su povezane sa povećanom produkcijom srčanih pro-oksidanasa, pri čemu je anaerobni intenzitet doveo do najvećeg porasta njihove produkcije.

Data on the effects of different types of training activities on the functional recovery of the heart after ischemia/reperfusion damage are still very inconsistent. An additional problem is the fact that it is still not known which type of training and its intensity (aerobic or anaerobic) achieves the best results in myocardial preconditioning. The aim of this stidy was examination of the effects of exercise preconditioning on an animal model of ischemia/reperfusion injury (I/R) of the rat myocardium, i.e. determination of the influence of different types of training processes on I/R, as well as the role of oxidative stress in the obtained effects. The study was conducted on 40 rats classified into one control (sedentary rats) and four experimental groups. Rats from the experimental groups were subjected to a training protocol of preconditioning by running and swimming (in aerobic and anaerobic form). After the training protocols, the animals were sacrificed, and the isolated hearts were perfused using the Langendorff retrograde perfusion method at a constant coronary perfusion pressure of 70 cmH2O. After stabilization, hearts were subjected to global ischemia for 20 min and then reperfusion for 30 min. Coronary flow values were determined flowmetrically, and left ventricular function parameters (dp/dt max, dp/dt min, SLVP, DLVP and HR) were continuously monitored. Oxidative stress parameters were determined in samples of coronary venous effluent, as well as in the blood of rats using spectrophotometric methods. Changes in the heart and quadriceps were determined by standard histological analysis. Both types of training only at aerobic intensities led to more efficient recovery of most cardiodynamic parameters, while in anaerobic zones they failed to achieve better effects compared to sedentary rats. In addition, both types of training were associated with increased production of cardiac pro-oxidants, with anaerobic intensity leading to the greatest increase in their production.

prekondicioniranje, trčanje, plivanje, ishemija/reperfuzija, izolovano srce, pacovi

preconditioning, running, swimming, ischemia/reperfusion, isolated heart, rat

612.176:572.087(043.3)

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