Immunohistochemical evidence for ATP receptors in human dental pulp.
Evidence is accumulating which supports a role for ATP in the initiation of pain by acting on P2X receptors, in particular P2X3, expressed on nociceptive afferent nerve terminals. To investigate whether this receptor plays a role in dental pain, we studied the presence and distribution of P2X3 receptors in human dental pulp, and their co-localization with other neural markers. Pulps were removed from extracted third molars and immunohistochemically stained with an antibody against P2X3 receptors. P2X3 immunoreactive (-ir) nerve fibers were detected in the main body of the pulp, in the sub-odontoblastic plexus of Raschkow, and within the odontoblastic area. Co-localization of the P2X3-ir neurons with neurofilament protein (NF) showed that the majority of the fibers were positive for both NF and P2X3. Double labeling with isolectin B4 (IB4) showed that all P2X3-ir neurons also bind IB4. We conclude that P2X3 receptors are present on both myelinated and unmyelinated nerve fibers in human dental pulp and may play a role in dental pain mechanisms.
Alavi
A M
AM
Autonomic Neuroscience Institute, Royal Free Hospital School of Medicine, London, UK. xmicron@aol.com
Dubyak
G R
GR
Burnstock
G
G
D000255:Adenosine Triphosphate / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D003782:Dental Pulp / Q000737:chemistry / Q000294:innervation / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D006801:Humans; D007150:Immunohistochemistry; D037102:Lectins / Q000032:analysis / Q000378:metabolism; D016900:Neurofilament Proteins / Q000032:analysis / Q000378:metabolism; D009619:Nociceptors; D009804:Odontoblasts / Q000378:metabolism; D018048:Receptors, Purinergic P2 / Q000032:analysis / Q000378:metabolism*; D058477:Receptors, Purinergic P2X3; D015398:Signal Transduction; D014098:Toothache / Q000378:metabolism*
D037102:Lectins; D016900:Neurofilament Proteins; C546407:P2RX3 protein, human; D018048:Receptors, Purinergic P2; D058477:Receptors, Purinergic P2X3; D000255:Adenosine Triphosphate