Immunocytochemical localization of the neurokinin 1 receptor in rat dental pulp.
The dentin-pulp complex is a peripheral end-organ supplied by dense sensory nerve fibers. Substance P, a representative neuropeptide widely distributed in the dental pulp, has been reported to play roles in pain transmission and the amplification of inflammation. We analyzed here the expression of the neurokinin 1 (NK1) receptor, preferentially activated by substance P, using immunocytochemistry in rat dental pulp at both the light and electron microscopic levels. Conspicuous NK1 receptor immunoreactivity was found in the odontoblasts; immunolabelings were present at their plasma membrane and endosomal structures, especially in their cytoplasmic processes. Immunoreactions for NK1 receptor were also detectable in a part of the nerve terminals associated with the cytoplasmic processes of the odontoblasts. Furthermore, the endothelial cells of capillaries and post-capillary venules and the fibroblasts were labeled with the NK1 receptor in the subodontoblast layer. These findings suggest that pulpal cells and nerve fibers are targets for substance P that mediate multiple functions, including a vasoactive function and the regulation of vascular permeability as well as the modulation of pain transmission.
Kido
Mizuho A
MA
Department of Oral Anatomy and Cell Biology, Graduate School of Dental Science, Kyushu University, Fukuoka, Japan. kido@dent.kyushu-u.ac.jp
Ibuki
Teiichi
T
Danjo
Atsushi
A
Kondo
Teruyoshi
T
Zhang
Jing-Qi
JQ
Yamaza
Takayoshi
T
Yamashita
Yoshio
Y
Higuchi
Yoshinori
Y
Tanaka
Teruo
T
D000595:Amino Acid Sequence; D000818:Animals; D002199:Capillary Permeability / Q000502:physiology; D003782:Dental Pulp / Q000098:blood supply / Q000378:metabolism* / Q000648:ultrastructure; D004730:Endothelium, Vascular / Q000737:chemistry / Q000502:physiology / Q000648:ultrastructure; D007150:Immunohistochemistry; D008297:Male; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D009804:Odontoblasts / Q000378:metabolism / Q000502:physiology / Q000648:ultrastructure; D051381:Rats; D017207:Rats, Sprague-Dawley; D018040:Receptors, Neurokinin-1 / Q000378:metabolism* / Q000502:physiology / Q000648:ultrastructure; D013373:Substance P / Q000378:metabolism / Q000502:physiology
D018040:Receptors, Neurokinin-1; D013373:Substance P