Effects of experimental pulpitis on the expression of transient receptor potential channels on the rat trigeminal ganglia.

摘要

Management of patients who present with tooth pain is one of the major challenges in dentistry. Further elucidation of mechanisms underlying tooth pain would lead to optimized management of these patients. Recent evidence suggests that Transient Receptor Potential (TRP) channels participate in pain sensation induced by chemical, thermal and mechanical stimuli. The aim of this study is to explore the molecular mechanisms underlying pulpitis by investigating the involvement of transient receptor potential vanilloid 1 (TRPV1) and transient receptor potential ankyrin 1 (TRPA1) channels in tooth pain using an animal model. Experiments were performed on 42 male Sprague--Dawley rats. Pulpitis was induced by drilling the first maxillary molar of the animal and treating the cavity with either complete Freund's adjuvant (CFA) or saline. Naive (untreated) rats were used as control. Trigeminal ganglia (TG) from both sides were extracted 1, 3 and 7 days after pulpitis induction and Western blot analysis was performed. The data was analyzed with one-way ANOVA or Kruskal-Wallis ANOVA on ranks depending on the outcome of normality test. TG from naive and pulpitis-induced rats showed the expression of both TRPV1 and TRPA1. Increased expression of both receptors was observed in TG of rats treated with saline and CFA, compared to naive (untreated) rats. However, results were not statistically significant due to a large variability. Potential factors that might have contributed to the variability, strengths and limitations of the pulpitis model employed in this study are discussed. Confirmation of our results with larger samples may provide a rationale for targeting these channels and reveal new therapeutic strategies for pulpitis.