Sodium channel Nav1.8 immunoreactivity in painful human dental pulp

Abstract

Background: The tetrodotoxin-resistant voltage-gated sodium channel Na_v1.8 (SNS1/PN3) is expressed by nociceptors and may play a role in pain states. Methods: Using specific antibodies for immunohistochemistry, we studied Na_v1.8 – immunoreactivity in human dental pulp in relation to the neuronal marker neurofilament. Human tooth pulp was extracted from teeth harvested from a total of twenty-two patients (fourteen without dental pain, eight patients with dental pain). Results: Fibres immunoreactive for Na_v1.8, were significantly increased on image analysis in the painful group: median (range) Na_v1.8 to Neurofilament % area ratio, non-painful 0.059 (0.006–0.24), painful 0.265 (0.13–0.5), P = 0.0019. Conclusion: Na_v1.8 sodium channels may thus represent a therapeutic target in trigeminal nerve pain states.