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.
Department of Oral Anatomy and Cell Biology, Graduate School of Dental Science, Kyushu University, Fukuoka, Japan. kido@dent.kyushu-u.ac.jp
Mizuho A
MA
Kido
Teiichi
T
Ibuki
Atsushi
A
Danjo
Teruyoshi
T
Kondo
Jing-Qi
JQ
Zhang
Takayoshi
T
Yamaza
Yoshio
Y
Yamashita
Yoshinori
Y
Higuchi
Teruo
T
Tanaka
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