Effects of ischemic preconditioning and iloprost on myocardial ischemia-reperfusion damage in rats

Abstract

This study investigates the effects of cardiac ischemic preconditioning and iloprost on reperfusion damage in rats with myocardial ischemia/reperfusion. 38 male Wistar Albino rats used in this study were divided into 5 groups. The control group (Group 1) (n=6), ischemia/reperfusion (IR) group (Group 2) (n=8), cardiac ischemic preconditioning (CIP) group (Group 3) (n=8), iloprost (ILO) group (Group 4) (n=8), and cardiac ischemic preconditioning + iloprost (CIP+ILO) group (Group 5) (n=8). Pre-ischemia, 15 minutes post-ischemia, 45 minutes post-reperfusion, mean blood pressure (MBP), and heart rates (HR) were recorded. The rate-pressure product (RPP) was calculated. Post-reperfusion plasma creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), troponin (cTn) vlaues, and infarct size/area at risk (IS/AAR) were calculated from myocardial tissue samples. Arrhythmia and ST segment elevations were evaluated during the ischemia and reperfusion stages. Although the MBP, HR, RPP values, biochemical parameters of CK-MB and LDH levels, IS/AAR rates, ST segment elevation values were found to be similar in CIP and CIP+ILO groups and the IR and ILO groups (p>0.05), CIP-containing group values had a positively meaningful difference (p<0.05) compared with the IR and ILO group. While mild-moderate findings of damage were observed in Group 3 and Group 5, severely findings of damage were releaved in Group 2 and Group 4. The arrhythmia score of the ILO group was meaningfully lower (F: 41.4, p<0.001) than the IR group. We can conclude that the effects of myocardial reperfusion damage can be reduced by cardiac ischemic preconditioning, intravenous iloprost reduced the incidence of ventricular arrhythmia associated with reperfusion, and its use with CIP caused no additional changes.

Keywords: Injury; iloprost; ischemia-reperfusion; ischemic preconditioning; myocardial.

Figure 1

Illustration of the experimental protocols. Hearts in all groups were subjected to 15 min of ischemia followed by 60 min reperfusion. IR: ischemia-reperfusion; CIP: cardiac ischemic preconditioning; ILO: iloprost.

Figure 2

A. Shown is a microscopic view of normal heart muscle (H&E stain, x40). B. Focal affect: mild – moderate degenerative changes on the left side, relatively normal areas on the right side (H&E stain, x100). C. Focal affect: mild – moderate degenerative changes on the right side, relatively normal areas on the left side (H&E stain, x40). D. Contraction band necrosis (H&E stain, x200). E. Inflammatory cell infiltration (H&E stain, x200). F. Coagulation necrosis with cytoplasmic eosinophilia, cytoplasmic vacuolization in cardiac muscle cells, loss of nuclei, edema, disorganization and degeneration in myocardial fibers (H&E stain, x200).

Figure 3

ST segment elevation. CIP: Cardiac Ischemic Preconditioning, IR: Ischemia-Reperfusion, ILO: Iloprost.

Figure 4

A. The creatine kinase-MB (CK-MB) and lactate dehydrogenase (LDH) values. B. Troponin (cTn) levels. C. Infarct size/area at risk (IS/AAR) ratio. D. Arrhythmia score. CIP: Cardiac Ischemic Preconditioning, IR: Ischemia-Reperfusion, ILO: Iloprost.