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

Abstract

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.