尾加压素Ⅱ促进大鼠主动脉球囊拉伤血管新生内膜形成和5-脂肪氧合酶的表达

Urotensin Ⅱpromotes formation of new vascular intima and expression of 5-lipoxygenase in rat aorta after balloon injury

目的观察尾加压素Ⅱ(UⅡ)对大鼠主动脉球囊拉伤血管新生内膜形成的促进作用和血管壁5-脂肪氧合酶(5-LO)表达的调控。方法雄性Wistar大鼠20只分为假拉伤组、拉伤组、拉伤+UⅡ[1nmol/(kg·h)]组(UⅡ组)和拉伤+UⅡ受体拮抗剂[Urantide 10nmol/(kg·h)]组(拮抗剂组),每组5只,3周后取胸主动脉切片,HE染色观察内膜增生,5-LO表达用免疫组织化学染色,计算增生内膜与中膜厚度比和面积比,观察各组血管壁5-LO表达情况。结果 HE染色显示,假拉伤组无内膜增生,拉伤组、UⅡ组、拮抗剂组内膜增生明显,UⅡ组较拉伤组血管内膜增生更明显,增生内膜/中膜面积比值增加0.16(P<0.01),增生内膜/中膜厚度比值增加0.54(P<0.01),拮抗剂组较拉伤组各项指标均无统计学差异(P>0.05)。免疫组织化学染色显示,假拉伤组血管几乎无5-LO表达,拉伤组主动脉可见较弱5-LO表达,与拉伤组比较,UⅡ组5-LO表达明显上调(P<0.05),拮抗剂组5-LO表达无明显变化(P>0.05)。结论 UⅡ能促进大鼠球囊拉伤后血管新生内膜的形成,并促进血管壁5-LO表达的上调。

Objective To study the role of urotensin Ⅱ （U Ⅱ ） in promoting the formation of new vascular intima and expression of 5-lipoxygenase （5-LO） in rat aorta after balloon injury. Methods Twenty male Wistar rats were divided into sham-operated （A） group, injured （B） group,injured-k UⅡ（1 nmol/kg · h） （C） group,injured＋urantide （10 nmol/kg · h,D） group （5 in each group）. The rats were killed after 3 weeks. The aorta was removed and cut into sections which were stained with HE for observing the intimal hyperplasia. Expression of 5-LO in different groups was detected with immunohistochemical staining. The ratio between the area and thickness of hyperplastic intima and media was calculated. Results HE staining showed no intimal hyperplasia in A group,significant intimal hyperplasia in B group, C group and D group, more significant intimal hyperplasia in C group than in B group,a 0.16 higher ratio between intima/media area and a 0.54 higher ratio between intima/media thickness in C group than in B group （P〈0.01） ,and no signif- icant difference in the above parameters between D group and B group （P〉0.05）. Immunohistochemical staining showed no 5-LO expression in A group, weak 5-LO expression in B group, upregulated 5-LO expression in C group, inflammatory cells infiltration in vascular adventia, less 5-LO staining in B group, and no sifinicant difference in 5-LO staining between D group and B group （P〉0.05）. Conclusion Urotensin Ⅱ can promote the formation of new vascular intima and upregulate the expression of 5-LO in rat aorta after balloon injury.