Differential effects of intrathecally administered N- and P-type voltage-sensitive calcium channel blockers upon two models of experimental mononeuropathy in the rat.

We investigated the effects of intrathecally administered N-type and P-type voltage-sensitive calcium channel (VSCC) blockers on the level of thermal hyperalgesia in two neuropathic pain models: the chronic constriction injury (CCI) model and the partial sciatic nerve injury (PSNI) model. N-type, but not P-type, VSCC blockers attenuated the level of thermal hyperalgesia induced by CCI in a dose-dependent manner. In the PSNI model, both N-type and P-type VSCC blockers had no effect on thermal hyperalgesia. This suggests that some types of neuropathic pain may be treatable with N-type VSCC blockers.