Temporal expression pattern of sodium channel Nav 1.8 messenger RNA in pulpitis.

AIM: To determine mRNA expression levels of Nav 1.8 in inflamed pulps of rats.

METHODOLOGY: Inflammation was induced by creating pulp exposures in rat incisors. Histopathological changes in the induced pulpitis were evaluated 1, 3, 7 and 10 days after exposure. Using real-time PCR, the relative mRNA expression levels of Nav 1.8 in the inflamed rat dental pulp was determined.

RESULTS

At day 1, no inflammation was evident in the pulp tissue, whereas increased levels of inflammatory responses were identified at day 3 and day 7. No pulpal inflammation was evident in day 10 or in the control group. Nav 1.8 was expressed in the rat dental pulp and increased at day 3 and day 7. Time course study of dental pulp inflammation indicated that differences in relative mRNA expression levels of Nav 1.8 were correlated with the severity of inflammation.

CONCLUSIONS

Nav 1.8 channels seem to be expressed significantly more under a temporal control so as to be associated with a severity of inflammation during pulpitis. As Nav 1.8 has been considered to have a role in neuropathic pain, its expression within dental pulp may contribute to the pathophysiology of tooth pain.