Resistance to reperfusion injury following short term postischemic administration of natural honey in globally ischemic isolated rat heart

摘要

Purpose:Results of our previous study revealed that preischemic perfusion of honey before zero flow global ischemia had cardioprotective effects in rat. The present study investigated potential resistance to reperfusion injury following short term postischemic administration of natural honey in globally ischemic isolated rat heart. Methods:Male Wistar rats were divided into five groups (n=10-13). The rat hearts were isolated, mounted on a Langendorff apparatus, allowed to equilibrate for 30 min then subjected to 30 min global ischemia. In the control group, the hearts were reperfused with drug free normal Krebs-Henseleit (K/H) solution before ischemia and during 120 min reperfusion. In the treatment groups, reperfusion was initiated with K/H solution containing different concentration of honey (0.25, 0.5, 1 and 2%) for 15 min and was resumed until the end of 120 min with normal K/H solution. Results:In the control group, VEBs number was 784?à199, while in honey concentration of 0.25, 0.5, 1 and 2%, it decreased to 83?à23 (P<0.001), 138?à48 (P<0.01), 142?à37 (P<0.001) and 157?à40 (P<0.01), respectively. Number and duration of VT and time spent in reversible VF were also reduced by honey. In the control group, the infarct size was 54.1?à7.8%, however; honey (0.25, 0.5, 1 and 2%) markedly lowered the value to 12.4?à2.4, 12.7?à3.3, 11.3?à2.6 and 7.9?à1.7 (P<0.001), respectively. Conclusion:Postischemic administration of natural honey in global ischemia showed protective effects against ischemia/reperfusion (I/R)injuries in isolated rat heart. Antioxidant and radical scavenging activity, lipoperoxidation inhibition, reduction of necrotized tissue, presence of rich energy sources, various type of vitamins, minerals and enzymes and formation of NO-contain metabolites may probably involve in those cardioprotective effects. var currentpos,timer; function initialize() { timer=setInterval("scrollwindow()",10);} function sc(){clearInterval(timer); }function scrollwindow() { currentpos=document.body.scrollTop; window.scroll(0,++currentpos); if (currentpos != document.body.scrollTop) sc();} document.onmousedown=scdocument.ondblclick=initialize190 |Vaezet al.Advanced Pharmaceutical Bulletin,2012, 2(2), 189-196Copyright . 2012by Tabriz University of Medical Sciencesbefore zero flow global ischemia had cardioprotective effects in rat.24In the present study, the effects of postischemic perfusion of natural honey on global myocardial ischemia/reperfusion injury were investigated in male rats. Materials and Methods Animals Adult male Wistar rats weighing 270-300 g were supplied by the Laboratory Animal Center, Medical Sciences University of Tabriz, Iran. The rats were divided randomly into five groups (n=10 -13) and were acclimated for at least 1 week at a temperature of 21?à3 .C and humidity 55?à5%. The animals were maintained with free access to standard rat food and tap water. The experiments reported were carried out in accordance with the Guide for the Care and Use of Laboratory Animals (National Institutes of Health Publication No 85-23, revised 1985). Chemicals Honey (Oskou, East Azerbaijan, Iran), Triphenyltetrazolium chloride (TTC, Sigma), Formalin, NaCl, NaHCO3, KCl, KH2PO4, MgSO4, CaCl2, D-glucose (Merck Company), Sodium pentobarbital (Kela Company, Belgium) and Heparin (Daru-pakhsh Company, Iran). Experimental protocols To prepare buffer solution for treatment groups, honey was dissolved in Krebs-Henseleit (K/H) solution for providing its different concentrations (0.25, 0.5, 1 and 2%). The rats were anesthetized by pentobarbital sodium (50 mg/kg) and heparinized (300 IU) via intraperitoneal injection.22The rat hearts were immediately excised and kept in ice cold oxygenated K/H solution (pH=7.4), before the aorta was cannulated on Langendorff apparatus. After mounting the hearts on a non-recirculating langendorff apparatus, they were perfused under constant pressure of 100 mmHg at 37 ??C and perfused with K/H solution that previously equilibrated with 95% O2-5% CO2 .22,25A water-filled polyvinylchloride balloon was attached to a pressure transducer and inserted into the left ventricle (LV) through an incision in the left atrium.22,25The hearts were allowed to equilibrate for 30 min (stabilization) and then subjected to 30 min no flow global ischemia by halting solution perfusion. In the control group, the hearts were reperfused with normal K/H solution for 120 min immediately after global ischemia. However, in the all treated groups, reperfusion was initiated with K/H solution containing different concentration of honey for 15 min and then resumed until the end of 120 min with drug free normal K/H solution. Evaluation of arrhythmias and infarct size The ECGs were recorded and analyzed according to the diagnostic criteria advocated in the Lambeth conventions26for determining cardiac arrhythmias including number of ventricular tachycardia (VT), number of total ventricular ectopic beats (VEBs=Single+Salvos+VT), durati