ABSTRACT
AIM:To determine the effects of different-term streptozotocin(STZ)-induced diabetes on ischemia/reperfusion(I/R)injury and cell apoptosis in rats myocardial via alterations in myocardial peroxynitrite.METHODS:The models of I/R injury were induced by occlusion and reperfusion of the left descending coronary artery(LDCA)in rats.I/R-induced infarct size was determined using triphenyltetrazolium chloride(TTC)staining.Quantified caspase-3 expression was used to represent apoptosis by Western blotting analysis.Peroxynitrite formation as indicated by nitrotyrosine level was measured by morphometric analysis.RESULTS:Two weeks after STZ treatment,infarct size(35.00%?3.00%)was smaller in 2 weeks diabetic hearts(2WKD)as compared with time-matched control group(2WKC)(51.00%?3.30%),whereas after 16 weeks of diabetes(16WKD),the infarct size(61.00%?3.00%)was bigger in the diabetic hearts as compared with the 16WKC group(50.00%?2.00%,P