mRNA expression in cultured calvaria osteocytes. (a) and (b) show FGF23 and Nurr1 mRNA expression in calvarial osteocytes treated with PTH, vehicle, PKA inhibitor (15 nM PKA inhibitor P6062), PKC inhibitor (5 µM PKC inhibitor SCP0214), or both. Expression normalized to housekeeping gene ornithine decarboxylase antizyme 1 (see Materials and Methods). Data shown are mean of triplicate. *P < 0.05.