Figure 3. Flow-induced stimulation of arteriolar NO.
A, DAF fluorescence indicates NO bioavailability in soleus muscle arterioles from young and old, sedentary and exercise trained rats at baseline and during flow stimulation (34 nl s−1). B, flow-stimulated changes in NO bioavailability, shown here as flow-induced to baseline fluorescence ratio (relative fluorescence), is reduced in soleus muscle arterioles from old SED rats. Exercise training restored flow-stimulated NO availability in arterioles from old rats and increased flow-stimulated NO availability in young rats. l-NAME inhibited flow-induced increases in DAF fluorescence in soleus muscle arterioles from all rats. *P < 0.05 vs. young SED, †P < 0.05 vs. respective SED group, and **P < 0.05 control vs.l-NAME. n= 8–10 per group.