Capsaicin receptor VR1 and ATP purinoceptor P2X3 in painful and nonpainful human tooth pulp.
OBJECTIVE
To investigate the levels of the capsaicin or vanilloid receptor-1 (VR1) and the ATP-gated purinoceptor P2X3 in painful and nonpainful human tooth pulps.


METHODS
Immunohistochemistry with specific antibodies and image analysis was used to quantify VR1- and P2X3-positive nerve fibers in painful (n = 13) and nonpainful (n = 33) human tooth pulps, and VR1 immunoreactivity was compared with immunoreactivity for the structural neuronal marker peripherin.


RESULTS
Strong VR1-like immunoreactivity was documented for the first time in dental pulp neurons. Weaker P2X3-like immunoreactivity was also detected in fewer nerve fibers. The ratio of VR1 to peripherin immunoreactivity was not significantly different between nonpainful and painful tissues (mean +/- SE% area of VR1 to peripherin; nonpainful 53.4 +/- 4.7%, n = 33; pulpitis 35.1 +/- 7.1%, n = 13; P = .07).


CONCLUSIONS
The presence of VR1 and P2X3 in fibers of human tooth pulp suggest that they may play a role in perception of dental pain, but further studies, including quantitation of their ligands, are necessary to elucidate any role they may play in pathophysiologic states.
Renton
Tara
T
Department of Oral and Maxillofacial Surgery, Guy's Tower, Guy's Hospital, London, United Kingdom.
Yiangou
Yiangos
Y
Baecker
Preston A
PA
Ford
Anthony P
AP
Anand
Prareen
P
D002211:Capsaicin / Q000378:metabolism; D003782:Dental Pulp / Q000294:innervation*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007381:Intermediate Filament Proteins / Q000378:metabolism; D008297:Male; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism; D009619:Nociceptors / Q000378:metabolism*; D064531:Peripherins; D011955:Receptors, Drug / Q000032:analysis / Q000378:metabolism*; D018048:Receptors, Purinergic P2 / Q000032:analysis / Q000378:metabolism*; D058477:Receptors, Purinergic P2X3; D014098:Toothache / Q000378:metabolism*
D007381:Intermediate Filament Proteins; D008562:Membrane Glycoproteins; D009419:Nerve Tissue Proteins; D009479:Neuropeptides; C546407:P2RX3 protein, human; C578994:PRPH protein, human; D064531:Peripherins; D011955:Receptors, Drug; D018048:Receptors, Purinergic P2; D058477:Receptors, Purinergic P2X3; D002211:Capsaicin