| Background and objectionDevelepment of angioplasty is constricted by restenosis. Recent reports suggested that insufficient apoptosis play a critical role in forming RS, apoptosis is controlled by some apoptosis related - genes, Bel -2 and Bax are important apoptosis related - genes. Tongxinluo is a compound Chinese herb which contains eight kind of ingredients. Previous studies suggested that Tongxinluo has the inhibitory effects on the formation of atherosclerosis and proliferation of vascular smooth mucle cell after injuried, but mechamism of that is unclear. Our study was submitted in rabbit of atherosclerosis narrow vessel model , to confirm Tongxinluo inhibited proliferation by promoting apoptosis.Materials and Methods1. Aminal model: 60 male white rabbits (2. 5-3. 5kg; 6-8month) , all the animals were divided into 3 groups; control group (normal diet plus intimal injury ) ,high -lipid group (high cholesterol diet plus intimal injury) ,Tongxinlou group(TongXinLuo0.5mg/kg/d, also high cholesterol diet plus intimal injury). After hypercholesterol diet (1.5g/kg/d)for 4 weeks, then the abdominal aortic endothelium were peeled off by balloon.The high - lipid group and Tongxinluo group continued to have hypercholesterol diet for another 4 weeks and followed by abdominal aortic angiography. The narrow parts of the vessel underwent anyio-plasty until being satisfied dilated with no stenosis, contrasting with adjacent unnarrowing parts. After 4 weeks all rabbits were killed and vessel samples were excised, respectively for the detection of histo-morphometry,immunohistochemical.2. Pathological analysis:Apoptosis was demonstrated by the terminal uridine nicle - end labeling(TUNEL) method,Expression of PCNA and Bcl -2,Bax protein were detected by immunohistochemical method. We detected the light density of positive cells by Metamorph Image System after staining.Statistic AnalysisAll the data were expressed as mean valus + standard deviation. Statistical significance was determined by t test and x2 analysisResult1. HE staining showed that the intimal of high - lipid group was increaing, Tongxinluo group was less than that of high -lipid group.2. The effect of Tongxinluo on the expression of PCNA and apop-tosis.The immunohistochemical staining showed that the light density of PCNA in TongXinLuo group is less than that of high - lipid group(p< 0.05). TUNEL staining showed that VSMC apoptosis in Tongxinluo ismore than that of high - lipid group (p<0.05 ).3. The effect of Tongxinluo on the expression of Bcl -2 and Bax.The results of immunohistochemistiy showed that light density of Bcl-2 in Tongxinluo group is less than that of high-lipid group(p< 0.05) , light density of Bax in Tongxinluo group is more than that of high - lipid group( P < 0.05 ).DiscussionApoptosis is different from necrocytosis , apoptosis is a progressing cell death . The balance of proliferation and apoptosis in VSMC decide the counts of SMC, insufficient apoptosis can lead to accumulation of SMC. Our study showed that apoptosis in high -lipid group is less than control group, and apoptosis in Tongxinluo is more than high -lipid group.The effect of Bcl - 2 is inhibiting apoptosis , and that of Bax is promoting apoptosis . their proportion decided cell survival. Present study showed the expression of Bcl - 2 in high - lipid group is more than control group, the expression of Bax is less than high - lipid group, we think it is related to decreasing apoptosis . we also find that the expression of Bcl - 2 in Tongxinluo is less than high - lipid, the expression of Bax is more than it.Above all , the decrease of VSMC apoptosis is caused by angio-plasty, Tongxinluo can promote VSMC apoptosis and it can upregulate the expression of Bax and dowregulate the expression of Bcl-2.Conclusion1. Bcl-2 and Bax participate in the regulation of VSMC after an-gioplasty.2. Tongxinluo promotes SMC apoptosis , decreases the expression of Bcl-2 and increases the expression of Bax.
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