Figure 2. Effects of α2- and α1-adrenoceptor agonists on smooth muscle myosin regulatory light chain (smRLC) phosphorylation in slow-twitch soleus and fast-twitch EDL muscles.
A, representative Western blots of skeletal muscle extracts showing clear separation between phosphorylated smRLC (lower bands) and non-phosphorylated smRLC (upper bands) in response to the α2-adrenoceptor agonist UK 14,304 and the α1-adrenoceptor agonist phenylephrine. B, results of quantitative densitometry of Western blots showing that both UK 14,304 (black bars) and phenylephrine (grey bars) increased smRLC phosphorylation in a concentration-dependent manner in soleus and EDL muscles. *P < 0.05 versus 0 μm drug; n≥ 4 muscles per concentration.