[The relation-ship between apoptosis, apoptosis related-gene expression and proliferative activity in smooth muscle...

To study the mechanism of graft vein stenosis.

A rat experimental model of autogenous vein graft was established by transplanting the right external jungular vein into the infrarenal abdominal aorta in 100 Wister rats. Electric microscope, TUNEL and immunohistochemical S-P technique were used to detect the apoptosis, the expression of apoptosis related-gene bcl-2 and bax and proliferation cell nuclear antigen (PCNA) of smooth muscle cells(SMCs) in vein graft.

From 1 to 8 weeks after replacement, the expression of apoptosis and PCNA of SMCs was continuously higher than the control group (P < 0.01). From 1 to 2 weeks, the expression of TUNEL and PCNA showed peak value. From 1 to 2 weeks, the positive rate of apoptosis was lower than that of PCNA, but from 4 to 8 weeks, the positive rate of TUNEL was higher than that of PCNA. There was obvious positive correlation between the expression of TUNEL and PCNA (r = 0.813 P < 0.05). One to 2 weeks after vein grafting, bcl-2 positive rate increased and was more different than the control group and the group of 4 to 8 weeks after vein grafting (P < 0.010).

The imbalance of proliferation and apoptosis may be related to the vessel remodeling and vein graft stenosis, and bcl-2 and bax protein may involve in the regulation of apoptosis of VSMC. Adopting the mixed strategy to regulate the balance between proliferation and apoptosis may be useful to prevent vein graft stenosis.