血管紧张素Ⅱ对废用性骨骼肌萎缩毛细血管重塑的影响

Effects of AngiotensinⅡ on Restructuring of Capillarization of the Skeletal Muscle of Amyotrophic Rat

目的:观察血管紧张素Ⅱ在废用性肌萎缩过程中对骨骼肌毛细血管重塑的影响。方法:以雌性SD大鼠为研究对象,按随机配对原则分成4组,即安静对照组(C)、安静+缓释血管紧张素Ⅱ组(CA)、悬吊组(T)、悬吊+缓释血管紧张素Ⅱ组(TA),每组8只。ATPase染色法分析骨骼肌毛细血管的变化情况,用单位面积骨骼肌毛细血管数量/肌细胞数量,即(C/F)观察毛细血管密度的变化;免疫印迹分析血管内皮生长因子(VEGF)及血管内皮生长因子2型受体(KDR)蛋白表达量的变化;免疫组化法观察VEGF及KDR在组织内的表达情况。结果:骨骼肌毛细血管染色结果显示,CA组与其他三组相比骨骼肌毛细血管密度(C/F)显著增多(P<0.05),而T组与C组相比C/F显著下降(P<0.05),TA与T组相比C/F略有升高,但没有统计学差异;免疫印迹结果显示,CA组与C组相比VEGF表达量下降,但KDR表达量上升;TA组与T组相比VEGF、KDR表达量均显著上升(P<0.05)。结论:正常情况下血管紧张素Ⅱ促进骨骼肌毛细血管的增长,在骨骼肌萎缩过程中,骨骼肌毛细血管密度下降,而血管紧张素Ⅱ对骨骼肌毛细血管密度有一定的维持作用。

Objective：To study the effect of angiotensin Ⅱ on the restructuring of capillarization of the skeletal muscle in the process of amyotrophy. Method ： female SD rats were randomly di- vided into four groups： control group（C）, control group with slow-released angiotensin Ⅱ agent （CA）, tail-suspended group （T）, tail-suspended with slow-released angiotensin Ⅱ agent group （TA）, 8 rats for each group. Myosin-ATPase histochemistry was used to assay the changes of the capillarization of the skeletal muscle, capillary/fiber （C/F） to observe the change of capillary density; Vascular endothelial growth factor （VEGF） and Vascular endothe- lial growth factor receptor-2 （KDR） protein content were performed by Western blotting and immunohistochemistry. Results： The results of Myosin-ATPase histochemistry： the capillary density （C/F） of CA group was increased significantly than other three groups （P〈0.05）, but the C/F of T group was decreased significantly than C group （P〈0.05）, and TA group was increased significantly than T group, but there was no significant difference between TA and C group. The results of Western blotting： protein content of VEGF of CA group was decreased significantly than C group, hut the protein content of KDR was increased. The content of both VEGF and KDR of TA group was increased significantly than T group （P〈0.05）. Conclusion ： In normal condition, angiotensin Ⅱ boost the increase of capillarization of the skeletal muscle in the process of amyotrophy, the capillary density was decreased, angiotensin Ⅱ can maintain the capillary density of the skeletal muscle in a certain degree.