Mechanism Of Intimal Proliferation In Rabbits Artery After Balloon Injury And Intervention Study Of Trapidil

Objectives To investigate the dynamic change of matrix metalloproteinase –2(MMP-2) and tissue inhibitors of metalloproteinase –2(TIMP-2) and their effect on intimal proliferation after balloon injury .To evaluate the effect of trapidil on intimal proliferation and the expression of Apolipoprotein J(Apo J) after balloon injury . Methods On the model of balloon injury of rabbit aortic artery, the change of intimal proliferation was observed under optical microscopy and the time course of MMP-2 and TIMP-2 mRNA level was examined with the method of RT-PCR. The effect of trapidil on intimal proliferation was observed under optical microscopy. The dynamic change of Apo J and the effect of trapidil on its expression were examined with the method of RT-PCR and immunohistochemistry .Results The intimal proliferation could be found in injured arteries.The MMP-2 and TIMP-2 mRNA level increased gradually after balloon injury. MMP-2 mRNA level reached the maximum at the seventh day,TIMP-2 mRNA level reached the maximum at the twenty-eighth day. The transcription of Apo J mRNA and expression of Apo J protein increased after balloon injury, mRNA transcription level reached the maximum at the first day,protein expression reached the maximum at the fourteenth day.The expression of Apo J protein correlated with intimal proliferation .Trapidil inhibited intimal proliferation and the expression of ApoJ mRNA and protein.Conclusions The dynamic change of MMP-2 and TIMP-2 mRNA after balloon injury plays an important role in intimal proliferation .The expression of Apo J after balloon injury correlates with intimal proliferation. The mechanism that trapidil suppresses intimal proliferation may involve the inhibitory effect on the expression of Apo J.