Abstract 12490: Effects of Muscle Stretching on Endothelium-Dependent Vasodilation and Skeletal Muscle Blood Flow of Aged Rats
Background: The aim of this study was to determine whether passive muscle stretching enhances endothelium-dependent vasodilation and increases blood flow in skeletal muscle arterioles of aged rats.
Methods: Stretching consisted of ankle dorsiflexion splinting, and was performed for 30 min daily for 4 wks in male Fischer 344 rats (n=16, 20 mo old). After splinting, soleus muscle arterioles were isolated, cannulated and pressurized at 70 cm H2O. We assessed vasodilation to acetylcholine (Ach) in the absence and presence of L-NAME, and endothelium-independent vasodilation to Dea-NONOate. We also measured blood flow to the soleus muscle, gastrocnemius muscle, tibialis anterior (TA) muscle, flexor hallicus longus (FHL) muscle, flexor digitorum longus (FDL) muscle and extensor digitorum longus (EDL) muscle with radioactive microspheres during walking at 15 m/min on a treadmill. Vasodilatory responses and skeletal muscle blood flows in the stretched limb were compared with those in the contralateral limb.
Results: Vasodilation to ACh was significantly greater in arterioles from the soleus muscle of the stretched limb than that of arterioles of the contralateral limb (P<0.01). In the presence of L-NAME, differences in vasodilation to ACh were eliminated. Responses to Dea-NONOate did not differ between arterioles of stretched and contralateral limbs. Blood flows to FHL and FDL muscles of the stretched limb were significantly higher than those of the contralateral limb (P<0.05, respectively). Blood flow to the soleus muscle of the stretched limb tended to be higher than that of the contralateral limb (P=0.056). Blood flows to the gastrocnemius, TA and EDL muscles did not differ between stretched and contralateral limbs.
Conclusion: These results indicate that daily passive muscle stretching enhances endothelium-dependent vasodilation, contributing to increased skeletal muscle blood flow during exercise in aged rats.
Author Disclosures: K. Hotta: None. B.J. Behnke: None. D. Christou: None. P. Ghosh: None. P. Maher: None. D. Kurien: None. R. Verma: None. J.M. Muller-Delp: None.
- © 2014 by American Heart Association, Inc.