Abstract 10850: Low-intensity Exercise Training Prevents Regression of the Capillary Network in the Soleus Muscle of Non-obese Type 2 Diabetic Rats
Background: Capillary regression in various tissues is one of the most common features associated with type 2 diabetes (T2DM). Exercise training effectively ameliorates some complications due to T2DM. The purpose of the present study was to explore the effects of low-intensity exercise training on the 3-D capillary network and associated angiogenic factors in the soleus muscle of non-obese T2DM rats.
Methods and Results: A cohort of Wistar rats was divided into a sedentary control (Con) and an exercise training (Con+Ex) group. A cohort of Goto-Kakizaki (GK) rats, a model of non-obese T2DM, was divided randomly into a sedentary (T2DM) and an exercise training (T2DM+Ex) group. The Con+Ex and T2DM+Ex rats were trained at a relatively low-intensity (serum lactate < 2 mmol/L) on a treadmill 6 times/week (60 min/day) for 3 weeks. The soleus 3-D capillary network was visualized with confocal laser microscopy and used to determine capillary volume. Muscle fiber succinate dehydrogenase (SDH) activity was determined via quantitative histochemistry. mRNA levels of several angiogenic factors (VEGF, KDR, Flt1, Ang1, Ang2, and Tie2), an anti-angiogenic factor (thrombospondin-1), and PGC1α were determined by TaqMan probe-based real-time PCR. Mean capillary volume was lower in T2DM than Con rats, whereas these values were higher in T2DM+Ex and Con+Ex than Con rats. SDH activity and PGC1α levels were higher in both exercise groups compared to both Con groups. The mRNA levels of all pro-angiogenic factors, except VEGF, were higher in the T2DM+Ex than T2DM rats. In addition, the levels of thrombospondin-1 were higher in both T2DM groups compared to both control groups.
Conclusion: These findings indicate that low-intensity exercise training ameliorates the regression of the soleus capillary network in diabetic rats that is due, at least in part, by the up-regulation of pro-angiogenic pathways.
- © 2012 by American Heart Association, Inc.