CYP17A1 and peripheral nerve injury: Thus, we examined whether: (1) intrathecal administration of progesterone affects mechanical allodynia and astrocyte activation in the spinal cord during the induction and maintenance phases of neuropathic pain in CCI mice; (2) sciatic nerve injury modulates the activity of spinal P450c17 via increase in the phospho-serine levels of P450c17; and (3) the P450c17 inhibitor, ketoconazole or the 5α-reductase inhibitor, finasteride attenuates the actions of progesterone on spinal astrocyte activation and mechanical allodynia induced by peripheral nerve injury.