Abstract: Objective To probe the function and mechanism of the fistular onion bulb（FOB）in promoting angiogenesis on myocardial infarction in rats. MethodsRandomly dividing the rats into 4 groups（10 in each group）：the FOB group，the Shexiang Baoxin pill group，the model group，and the sham operation group. After one week of adaptive feeding，the model of left anterior descending coronary artery ligation was performed. The quantity and density of microvascular in the margin of myocardial infarction were observed by CD34 immunohistochemical staining. Serum TGF-β content was detected by ELISA. The protein levels of MEK and ERK in the left ventricular myocardium of rats were detected by Western Blot. The mRNA expression levels of MEK and ERK in the edge of myocardial infarction were detected by RT-PCR. ResultsCompared with the model group，The MVD value of CD34 staining in The FOB group and the Shexiang Baoxin pill group was significantly increased（P < 0. 01）. The MVD value in The FOB group was lower than that in the Shexiang Baoxin pill group（P < 0. 01）. Compared with the model group，the level of serum TGF-β in the FOB group was significantly increased（P < 0. 01），and the level of TGF-β in the Shexiang Baoxin pill group was also increased（P < 0. 05）. The protein expression levels of MEK and ERK were increased，and the amplification factor of MEK and ERK mRNA was significantly increased （P < 0. 01）. Compared with the Shexiang Baoxin pill group，the ERK protein expression level，and the ERK mRNA amplification multiple were lower in the FOB group（P < 0. 01， P < 0. 05），and the MEK protein expression level had no significant difference（P > 0. 05）. ConclusionThe FOB can promote the angiogenesis of myocardial infarction and increase the number of neovascularization at the edge of myocardial infarction. The mechanism may be related to the up-regulation of serum TGF- β level and the expression of the MEK/ERK signaling pathway.

Key words: fistular onion bulb（FOB）, myocardial infarction, angiogenesis, TGF-β, MEK/ERK