Fig. 10. The mechanisms of the effects of procaine on carbachol-induced extracellular signal-regulated kinase (ERK) activation in PC12 cells. ( A ) There were no effects of procaine on the AlF4−-induced ERK activation. The cells were treated with or without 5 × 10−4M procaine and then stimulated with 10 mM NaF plus 10 μM AlCl3for 30 min. ( B ) There were no effects of calyculin A on the procaine inhibiting the carbachol-induced ERK activation. The cells were exposed to the presence (+) or the absence (−) of 10 nM calyculin A for 10 min and then 5 × 10−4M procaine was added. Ten minutes after procaine treatment, the cells were stimulated with 1 mM carbachol for 2 min. Proteins were subjected to sodium dodecyl sulfate–polyacrylamide gel electrophoresis and analyzed by immunoblotting with anti-ERK antibody. The upper two arrows on the left indicate ERK1 ( 
, active forms of ERK1) and the lower two indicate ERK2 ( 
, active forms of ERK2).
