A, PTH receptor expression in response to ox-PAPC. RNA was isolated from cells treated for 6 days with ox-PAPC (10 μg/ml). Expression was assessed by real-time RT-PCR and normalized to β-actin. B, cAMP production in response to PTH and ox-PAPC. cAMP accumulation in the medium of cells pretreated for 7 days with ox-PAPC, followed by treatment for an additional 30 min with vehicle, PTH (10−8 m), and/or ox-PAPC (10 μg/ml). C, Nurr-1 and IL-6 expression in response to PTH and ox-PAPC. RNA isolated from cells pretreated for 6 days with ox-PAPC, followed by treatment for an additional 2 h with vehicle, PTH (10−8 m), and/or ox-PAPC (10 μg/ml). Expression was assessed by real-time RT-PCR and normalized to β-actin. Results are shown as mean ± S.E. from all experiments. *, p < 0.0001; #, p < 0.005; **, p < 0.05.