نقش متغير زمان بر تغييرات آپوپتوزيس متعاقب ايسكمي - رپرفيوژن در قلب ايزوله موش صحرايي

Time dependent effects of ischemic-reperfusion on ratʹs cardiomyocytesapoptosis

Background: The study objective was to investigate time dependent effects of ischemic- reperfusion on cardiomyocyte apoptosis. Materials and Methods: Male Sprague-Dawley rats (270-330 gr) were randomly divided into four groups (n=10) and anesthetized by sodium pentobarbital {50-60 mg/kg-IP). The hearts of rats in each of three treatment groups were removed and quickly mounted on a Langendorff apparatus and perfused by a modified Krebs-Henseleit solution under constant pressure at 37°C. During the stabilization time, 30 minute regional ischemia (which was followed with 60, 90 or 120 minute reperfusion in respective T/60min, T/90 min and T/120 min reperfusion groups) was established, while in the control group the hearts were intact. Immunohistochemical detection of apoptotic cells was performed using an in-situ cell death detection (TUNEL) kit. The positive cardiomyocytes counted in five random high power fields in each sample. Data were presented as mean±SEM for each group. Results: In the control group, the number of apoptotic cells was 1.0±0.4, while in the treatment groups of T/60min, T/90 min and T/120 min reperfusion, the corresponding numbers were 2.0±0.5, 3.0±0.3 and 6.0±0.3, respectively. Although the difference between T/60 min & T/90 miri and T/60 min & control group was not significant (p>0.05), the difference between T/60 min & T/120 min (p<0.001), T/90 min & T/120 min (p<0.01), T/90 min & control (p<0.01) and T/120 min & control (pO.OOl) was significant. Conclusion: We demonstrated that the duration of ischemic-reperfusion insult can affect the apoptosis changes in cardiomyocytes.