Treadmill running improves diabetes‐induced capillary regression in skeletal muscle through activation of VEGF and angiopoietin pathways without inhibition of thrombospondin‐1

Abstract

PURPOSEExercise has been shown to be an effective treatment in the prevention of some complications due to type 2 diabetes (T2DM). The purpose of this study was to investigate the effects of treadmill running on the capillary regression and associated angiogenic factors in the soleus muscle of T2DM rats.METHODSGoto‐Kakizaki (GK) and Wistar rats were randomly divided into an exercise training (T2DM+Ex, Con+Ex) and a sedentary group (T2DM, Con). The T2DM+Ex and Con+Ex rats were run at a low‐intensity on a treadmill 6 times a week for 3 weeks. The capillary in soleus muscle was visualized using 3‐D method. The expression of pro‐angiogenic factors, and anti‐angiogenic factor, thrombospondin‐1 (TSP‐1), in the soleus muscle were determined by TaqMan probe‐based PCR.RESULTSAlthough the capillary volume of the soleus muscle was lower in T2DM than in Con rats, that in T2DM+Ex and Con+Ex was higher than that in Con. VEGF and Angiopoietin pathways in the T2DM+Ex were significantly increased compared with those in other groups although TSP‐1 level increased.CONCLUSIONThese findings suggest that treadmill running improves the regression of capillary in diabetic muscle, and the pro‐angiogenic pathways in diabetic muscle could be up‐regulated by exercise. Supported by Grants‐in‐Aid for Science Research from the Japanese Ministry of Education, Culture, Sports, Science and Technology.