Corticotropin releasing factor receptor expression in painful human dental pulp

• CRF-R2 is increased in symptomatic pulp compared to asymptomatic pulp.
• CRF-R2 is not localized within the nerve fibres of the dental pulp.
• Increased nerve sprouting is observed in painful pulp.

BackgroundOur objective was to correlate the presence of symptoms and dental pulp injury with the amount of a subtype of corticotropin releasing factor receptor (CRF-R) in symptomatic and asymptomatic human teeth. We hypothesized that patients diagnosed with irreversible pulpitis have increased levels of CRF-R.Materials and methodsDental history, diagnosis and radiographs were obtained from treatment records following extractions. Teeth were diagnosed as asymptomatic or symptomatic demonstrated by clinical and radiographic evaluation. Tissue sections from tooth pulp were immunoreacted with antibodies directed against CRF receptor 2 (CRF-R2) and neurofilament protein and examined to correlate CRF-R expression with pulpal diagnosis.ResultsOur results indicated that symptomatic pulps demonstrated significantly greater expression of CRF-R2. The increased expression was localized on distinct cellular profiles throughout the pulp and was not directly correlated with neurofilament expression.ConclusionsOur findings suggest that the analgesic effects of endogenously produced CRF may be enhanced via upregulation of CRF-R2 expression, and may explain the occurrence of reduced pain symptoms in some patients with irreversible pulpitis. The application of CRF-R agonists may be a feasible strategy in reducing pain associated with irreversible pulpitis.