Figure 4. Haemodynamic measures in the soleus and gastrocnemius muscles measured in conscious, resting young and old rats.

A, resting haemodynamic measures for the soleus and gastrocnemius (Gastroc.) muscles, as well as the separate sections of the gastrocnemius muscle. There were no age-related differences in blood flow to the soleus or gastrocnemius muscle, or the different sections of the gastrocnemius. B, calculated resting shear stress for the soleus and gastrocnemius muscles, as well as for the red, mixed and white fibre-type sections of the gastrocnemius muscle. There were no age-related differences in shear stress to the soleus or gastrocnemius muscles; however, the old animals demonstrated lower shear stress in feed arteries of the red and white portions of the gastrocnemius muscle than in corresponding arteries from the younger animals. *P < 0.05 versus young.