Effect of Stent Implantation on the Expression of PCNA and Cyclin E and Apoptosis in Rabbit Vascular Smooth Muscle Cells / 中山大学学报(医学科学版)

ABSTRACT

【Objective】To evaluate the impact of stent implantation on proliferation and apoptosis in media vascular smooth muscle cells and to explore the mechanism of restenosis after stent implantation.【Methods】Fifty male New Zealand rabbits were randomized into balloon group and stent group.Control group were set up.The materials were harvested on 3,7,14,28 and 56 day after operation and the following investigation were carried out.① Assessing the expression of proliferating cell nuclear antigen (PCNA) and Cyclin E of media smooth muscle cells with immunohistochemistry;② Analyzing apoptosis of media smooth muscle cells by TUNEL technique.【Results】The expressions of PCNA,Cyclin E and apoptosis in stent and balloon groups were markedly increased compared to control groups.① Stent group induced significant increased expression of PCNA and Cyclin E in the media smooth muscle cells compared to balloon group.On day 7,the positive rates of PCNA and Cyclin E were 24.36±0.55% vs 18.74±1.09% (P<0.01) and 22.65±1.00% vs 17.68±1.10% (P<0.01) respectively;② Stent group induced much more significant apoptosis than balloon group.The highest rate of apoptosis appeared on day 7:12.46±1.13% vs 5.54±0.53% (P<0.01);③By calculating the ratio of positive rates of PCNA to apoptosis and Cyclin E to apoptosis respectively,the ratio of balloongroup was higher than that of stent group.【Conclusion】Stent group induces augmented proliferation and much more significant apoptosis of media smooth muscle cells compared to balloon group.It shows that the severity of restenosis is relieved after stent implantation.