Effects Of Angiotensin â…¡ On Restructuring Of Capillarization Of The Skeletal Muscle Of Amvotrophic Rat

Objective:to study the effect of angiotensinll on the restructuring of capillarization of the skeletal muscle and the transformation of muscle fiber type in the process of amyotrophy.Method:female SD rats were randomly divided into four groups:control group(C),control group with slow-released angiotensinâ…¡agent(CA),2 weeks of tail-suspended group(T),2 weeks of tail-suspended with slow-released angiotensinll agent group(TA),8 rats/group. Myosin-ATPase histochemistry was used to assay the changes of the transformation of muscle fiber type and the capillarization of the skeletal muscle,capillary/fiber(C/F) to observe the change of capillary density; Vascular endothelial growth factor (VEGF) and Vascular endothelial 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 C group (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,To compare with C group, the ratio of muscle fiber typeâ…¡of group T was significantly increased(P<0.05). but TA group was significantly decreased than T group(P<0.05). The results of Western blotting:protein content of VEGF of CA group was decreased significantly than C group, but 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, angiotensinâ…¡boost the increase of capillarization of the skeletal muscle, and it may make the muscle fiber type chansform from Ha type toâ…¡b type; In the process of amyotrophy, the capillary density was decreased, muscle fiber type I transformed into typeâ…¡, but angiotensinâ…¡restrain the change of muscle fiber type from slow to fast type, and it can maintain the capillary density of the skeletal muscle in a certain degree.