J Korean Acad Conserv Dent.  2007 Nov;32(6):514-521.

Expression of P2X3 and its colocalization with trpv1 in the human dental pulp

• Kim YK
• Kim SK

Abstract

The purinoreceptor, P2X3 is a ligand-gated cation channel activated by extracellular ATP. It has been reported that ATP can be released during inflammation and tissue damage, which in turn may activate P2X3 receptors to initiate nociceptive signals. However, little is known about the contribution of P2X3 to the dental pain during pulpal inflammation. Therefore, the purpose of this study was to investigate the expression of P2X3 and its colocalization with TRPV1 to understand the mechanism of pain transmission through P2X3 in the human dental pulp with double labeling immunofluorescence method. In the human dental pulp, intense P2X3 immunoreactivity was observed throughout the coronal and radicular pulp. Of all P2X3-positive fibers examined, 79.4% coexpressed TRPV1. This result suggests that P2X3 along with TRPV1 may be involved in the transmission of pain and potentiation of noxious stimuli during pulpal inflammation.

Keyword

P2X3 receptor; Immunofluorescence method; Human dental pulp; TRPV1; Transmission of pain

MeSH Terms

Adenosine Triphosphate
Dental Pulp*
Fluorescent Antibody Technique
Humans*
Inflammation
Receptors, Purinergic P2X3
Adenosine Triphosphate
Receptors, Purinergic P2X3

Figure

• 

  Figure 1 Photomicrographs of P2X3 immunoreactive nerve fibers in the human dental pulp (× 200). A shows P2X3 immunoreactive nerve fibers (arrows) accompanying blood vessel (asterisks) in the coronal pulp, and B shows P2X3 immunoreactive nerve fibers (arrows) in the radicular pulp. Scale bars in A and B = 50 µm.

• 

  Figure 2 Photomicrographs showing the colocalization of P2X3 with TRPV1 (× 200). A and B show nerve fibers those are double stained with antibodies against P2X3 (red), and TRPV1 (green). Scale bars in A and B = 50 µm.

• 

  Figure 3 Photomicrographs showing the nerve fibers stained for P2X3 only (× 200). A shows P2X3 immunoreactive nerve fibers (arrows). B shows no double stained fiber at the same positions in A (arrows). Scale bars in A and B = 50 µm.

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