血脂康对自发性高血压大鼠血管重构及胶原蛋白的影响

The Effects of Xuezhikang on Vascular Remodeling and Collagen in Spontaneously Hypertensive Rats

摘要:

目的 探讨自发性高血压大鼠（SHR）主动脉血管重构细胞外基质蛋白和胶原蛋白的改变以及血脂康干预后的效果分析。方法 30只8周龄雄性SHR大鼠随机分为血脂康低剂量组［20 mg/（kg·d），n10］、血脂康高剂量组［200 mg/（kg·d），n10］和安慰剂组（n10），同周龄雄性Wistar大鼠作为对照组（n10），所有大鼠喂养至16周龄，静脉抽血后离心，分离血清采用酶联免疫吸附法测定血清基质金属蛋白酶9（MMP-9）、组织型基质金属蛋白酶抑制剂（TIMP-1）水平；同时取胸主动脉，HE染色分析血管壁厚度和管壁/腔比值；Masson三色染色分析血管胶原纤维变化；免疫组织化学染色分析胸主动脉MMP-9、TIMP-1蛋白表达，运用Image-Pro Plus 6.0软件对免疫组织化学染色切片进行灰度定量。结果 16周龄大鼠血清MMP-9水平在安慰剂组明显高于对照组（124.60±30.01 μg/L比66.00±22.67 μg/L，P<0.01）；经血脂康治疗后，血脂康高剂量组血清MMP-9水平明显低于安慰剂组（67.96±8.80 μg/L比124.60±30.01 μg/L，P<0.05）。血清TIMP-1水平在SHR大鼠明显高于对照组，差异有统计学意义（P<0.01）；但高血压大鼠组间差异无统计学意义 （P>0.05）。16周龄的SHR大鼠（安慰剂组）胸主动脉与Wistar大鼠（对照组）比较，可见血管壁明显增厚，管壁/腔比值增大（P<0.05），弹性纤维排列紊乱，管壁胶原成分显著增多；经血脂康治疗后，血脂康高剂量组管壁/腔比值明显低于安慰剂组（6.8%±0.9%比7.8%±0.7%，P<0.05），两个治疗组胶原均有所减少，血脂康高剂量组胶原数量接近于对照组。胸主动脉免疫组织化学染色显示安慰剂组MMP-9表达明显强于对照组和血脂康治疗组；经灰度定量后，安慰剂组MMP-9灰度值明显高于血脂康高剂量组和对照组，差异有统计学意义（P<0.01）。TIMP-1在各组表达中并不明显，灰度定量差异无统计学意义。结论 高血压大鼠出现血管重构，表现为MMP-9水平升高和主动脉壁胶原蛋白沉积增加，血脂康能抑制MMP-9水平和胶原蛋白沉积，减轻血管重构的程度。

关键词:自发性高血压大鼠;血管重构;细胞外基质;胶原蛋白;血脂康

Abstract:

Aim To investigate the pathological changes of vascular remodeling and collagen in spontaneously hypertensive rats（SHR） and the effect of treatment by Xuezhikang. Methods 30 male SHR at 8-week-old were randomly divided into three groups （n10 each）: Xuezhikang low dose group （XZK-L group,Xuezhikang 20 mg/（kg·d））,Xuezhikang high dose group （XZK-H group,Xuezhikang 200 mg/（kg·d）） and placebo group,sex and age matched Wistar rats （control group,n10） were also designed. 8 weeks after intragastric administration,the levels of serum matrix metalloproteinase-9（MMP-9） and tissue inhibitors of metalloproteinase-1（TIMP-1） were measured by enzyme linked immunosorbent assay （ELISA）. The thoracic aortas were collected for hematoxylin-eosin （HE） stain to detect vascular wall thickness and Wall-to-lumen area ratio （W/L）. The aortic collagen was showed by Masson trichrome stain. The thoracic aortas were observed by immunohistochemistry to detect the expressions of MMP-9 and TIMP-1. Quantitation of the protein content of MMP-9 and TIMP-1 was assessed by computerized planimetry in the aortic media in immunohistochemically stained slides by using Image-Pro Plus 6.0. Results The level of serum MMP-9 in placebo group was significantly increased compared with XZK-H group and control group （P<0.05）. The levels of serum TIMP-1 in the SHR groups were higher than control group（P<0.01）. There was no significance of the levels of TIMP-1 in all SHR group （P>0.05）. Aortas of SHR showed wall thickening,increasing wall-to-lumen area ratio and collagen,disordered fibres. The thickness of vascular wall and W/L ratio of SHR were significantly higher than those of Wistar rats （P<0.05）. Arteries in XZK group showed less collagen in aortic wall than that of placebo group,especially the XZK-H group was near to the control group. In the placebo group,MMP-9 protein expression was significantly increased in the thoracic aorta compared with control group and XZK-H group（P<0.05）. However,the level of TIMP-1 had no significance in the four groups （P>0.05）. Conclusions Hypertensive vascular remodeling shows elevated level of MMP-9 and collagen deposition. While Xuezhikang can inhibit the elevated MMP-9 and collagen deposition,improve vascular remodeling in hypertension.

Key words:Spontaneously Hypertensive Rat Vascular Remodeling Extracellular Matrix Collagen Xuezhikang