The effect of valsartan eluting-stent on the neo-intima and expression of angiotensin Ⅱ type 2 receptor in experimental rabbits / 中国介入心脏病学杂志

ABSTRACT

Objective To study the effect of valsartan eluting-stent on vascular neointimal formation and angiotensin Ⅱ type 2 receptor (AT2R) expression and to access its feasibility to prevent in-stent restenosis and the mechanism. Methods Both the valsartan eluting-stents and the carrier eluting-stents were made with multi-layers coated methods. Bare stents, carrier eluting-stents and valsartan eluting-stents were implanted into the rabbits' abdominal aortias respectively. Abdominal aorta angiography was performed before and right after the operation and at 3 months after stent inplantation. The mean diameter of aortas in different groups were measured by Quantitative coronary angiography software. All the rabbits were killed 3 months after the procedure and the cross section of the stented vessel were analysed for neointimal formation. The luminal area, neointimal area, inner elastic membrane luminal area and the maximal inner-membrane thickness were compared between the 3 groups. The expressions of AT2R mRNA and the protein were determined by RT-PCR and histomorphometry. Results There were no significant differences in the mean aortic diameters among the 3 groups.The greatest luminal area and the minimal neointimal hyperplasia was found in the valsartan eluting-stents group compared with the other two groups. The mean luminal areas of the bare stents, carrier eluting stents and the valsartan eluting-stents were 4 345 548?1 258 22 ?m2, 4 302 061?167 952 ?m2 and 5 016 269?207 934 ?m2; the mean neointimal areas were 1 119 635?163 503 ?m2, 1 135 636?136 555 ?m2 and 441 577?74 099 ?m2 and the mean maximal inner-membrane thickness were 210?30 ?m, 192?21 ?m and 116?12 ?m respectively.The level of AT2R mRNA expression in the valsartan eluting-stents group was higher than that in the other two groups. The transcription of AT2R protein showed similar trend. Conclusion Valsartan eluting-stents enhanced AT2R mRNA and protein expression and inhibited neointimal hyperplasia which might play an important role in preventing restenosis.