Fig. 4. Effects of 4-amino-5-(4-chlorophenyl)-7-(t-butyl) pyrazolo[3,4-day]pyrimidine (PP2, 10−5m), 8 bromo cAMP (8B, 4 × 10−3m), 3-isobutyl-1-methylxanthine (IBMX, 10−4m), and H89 (10−5m) on dexmedetomidine (Dex, 10−6m)–induced extracellular signal–regulated protein kinase 2 biphosphorylation (pERK2). Data (mean ± SD) are expressed as a fractional pERK2 on actin ratio increase from basal phosphorylation (control: 100%). Analysis of variance for pERK2 was F = 901.9, P < 0.0001. Post hoc analysis used Bonferroni correction. *** P < 0.0001 versus control, # P < 0.0001 versus PP2. NS = not significant.