Fig. 1.

Effect of dopamine on the level of phospho-DARPP-32 in neostriatum. Slices were incubated with dopamine (100 μm) in the presence of the dopamine uptake inhibitor nomifensine (10 μm) for the indicated times.A, Phospho-DARPP-32 was detected at a molecular mass of ∼32 kDa using mAb-23 against thr³⁴-phospho-DARPP-32. Note that the phospho-DARPP-32 mAb also detected a cross-reactive protein band at a molecular mass of ∼75 kDa, the levels of which were not affected by dopamine. B, Total DARPP-32 was detected in the same membrane as shown in A using mAb C24–5a against DARPP-32. C, The amount of phospho-DARPP-32 was quantitated by densitometry, and the data were normalized to values obtained with untreated tissue. Data represent mean ± SEM for the number of experiments shown in parentheses. * p < 0.05, ** p < 0.01 compared with 0 min; †p < 0.05 compared with 2 min.