ABSTRACT
<p><b>OBJECTIVE</b>To investigate the mechanism of myocardial cell apoptosis during delayed preconditioning induced by Sini decoction (SND).</p><p><b>METHOD</b>SD rats were divide into four groups: control, sham, I/R and SND groups. The rats in I/R group, left anterior descending coronary artery (LAD) was occluded for 1h and reperfused for 1 h. The rats in SND group were pretreated with Sini decoction (5 g x kg(-1) x d(-1)) for three days, the last treatment was pretreated 24 h before the index occlusion. Cell apoptosis was measured by flow cytometry, cytochrome C and bcl-xl were detected by Western blotting and the activity of caspase-3 was detected by assay kit.</p><p><b>RESULT</b>As compared with I/R group, apoptosis rate of myocardial cell, the release of cytochrome C from mitochondria and the activity of caspase-3 were significantly decreased, and the expression of bcl-xl protein was elevated in SND group.</p><p><b>CONCLUSION</b>The delayed preconditioning induced by Sini decoction decreased myocardial cell apoptosis. The mechanism may be related to the inhibition of mitochondria signal pathway of apoptosis.</p>