Effects of cardioplegic solution on cytokine expression

Background. Ischaemia-reperfusion (I/R) injury leads to cell death and triggers inflammatory responses. Cardioplegic solutions are essential in cardiac surgery to induce controlled cardiac arrest and protect the myocardium from ischemic damage and ischaemia-reperfusion injury. Aim. The aim of this study was to evaluate the impact of different cardioplegic solutions — del Nido, Custodiol HTK, and St. Thomas on cytokines response in an immature rat heart using the Langendorff preparation. Methods. 30 male Wistar albino rats (up to 1 month age) were used. A median sternotomy was performed. After the heart was removed, the aorta was gently cannulated and ligated using double 5-0 silk sutures. We employed the retrograde heart perfusion model described by O. Langendorff. Experimental animals were divided into three groups: St. Thomas (CP1), Custodiol HTK (CP2), and del Nido (CP3) group. Moreover, each of these groups was divided into three groups according to ischaemia time: 1 h ischaemia with 20 min reperfusion time, 2 h ischaemia with 40 min reperfusion time, 4 h ischaemia with 80 min reperfusion, and control groups (KPRF) with 30 minutes of perfusion was performed in the control group. Cardioplegic solutions approximately 10 ml, were infused into the aorta. Ventricular biopsies were harvested and stored at –80 o C until analysis. Results. Pro-inflammatory cytokines TNF-alpha and IL-6 and anti-inflammatory cytokines IL-4 and IL-10 were evaluated. The results showed that there was no statistically significant difference between the groups (p > 0.05). However, under conditions of prolonged ischaemia, inflammation was reduced the most in the CP2 group. It is clearly seen that the number of anti-inflammatory cytokines decreases over time in all cardioplegic groups. Looking at IL-10, the amount in the CP3 group remains the highest after four hours, while the results in the CP2 group are more stable. However, for IL-4, CP2 and CP3 appear similar, while CP1 shows higher values at 2 h but experiences larger drops at 4 h of ischaemia. Conclusion. Although no statistically significant differences were found between the groups, cytokine analysis revealed that, anti-inflammatory cytokines more accurately reflect the initial changes in the immature myocardium.