OBJECTIVETo investigate the expression change of matrix metalloproteinase-9 (MMP-9) and nuclear factor-kappaB (NF-kappaB) induced by Xuemaitong capsule (XMT) preconditioning on rats of myocardial ischemia, and provide experimental evidence for the protection of XMT.

METHOD60 wistar rats were randomly divided into 5 roups: the control group, the model group, the three difference dose groups of XMT. The groups of XMT were treated by continuous 14 days intragastric administration. After 14 days, except the control group, all groups were continuous 2 days subcutaneous injected with isoproterenol 30 mg x kg(-1) every day. Before and 5, 10, 20, 30 minutes after subcutaneous injection, electrocardiogram were recorded, immunohistochemical staining, RT-PCR and image analysis were also measured for the investigation of the expression of MMP-9 and NF-KB in the ischemic region.

RESULTCompared with the model group, the delta sigma-ST of electrocardiogram of the high dose, middle dose, low dose groups of XMT decreased at different degree. Pathological conditions of ischemic myocardial ameliorated. The immunohistochemical staining and RT-PCR indicated that the expression of MMP-9 and NF-kappaB decreased in the high dose group (P < 0.05), the mRNA expression of MMP-9 and NF-kappaB decreased in the high dose group (P < 0.05).

CONCLUSIONThe expression of MMP-9 and NF-kappaB increased after myocardial ischemia After high dose treated by XMT, the expression reduction of MMP-9 and NF-kappaB indicated that XMT played an important preventive role in acute myocardial ischemia.