Immunohistochemical localization of dopamine D2 receptor in the rat carotid body.
Dopamine modulates the chemosensitivity of arterial chemoreceptors, and dopamine D2 receptor (D2R) is expected to localize in the glomus cells and/or sensory nerve endings of the carotid body. In the present study, the localization of D2R in the rat carotid body was examined using double immunofluorescence for D2R with various cell markers. D2R immunoreactivity was mainly localized in glomus cells immunoreactive to tyrosine hydroxylase or dopamine β-hydroxylase (DBH), but not in S100B-immunoreactive sustentacular cells. Furthermore, D2R immunoreactivity was observed in petrosal ganglion cells and nerve bundles in the carotid body, but not in the nerve endings with P2X2 immunoreactivity. In the carotid ganglion, a few punctate D2R-immunoreactive products were detected in DBH-immunoreactive nerve cell bodies. These results showed that D2R was mainly distributed in glomus cells, and suggested that D2R plays a role in the inhibitory modulation of chemosensory activity in a paracrine and/or autocrine manner.
Laboratory Animal Research Center, Fukushima Medical University School of Medicine, Fukushima, Japan.
Jun
J
Wakai
Laboratory of Veterinary Anatomy and Cell Biology, Faculty of Agriculture, Iwate University, Morioka, Japan.
Anna
A
Takayama
Laboratory of Veterinary Anatomy and Cell Biology, Faculty of Agriculture, Iwate University, Morioka, Japan.
Takuya
T
Yokoyama
Laboratory of Veterinary Anatomy and Cell Biology, Faculty of Agriculture, Iwate University, Morioka, Japan.
Nobuaki
N
Nakamuta
Laboratory for Anatomy and Physiology, Department of Sport and Medical Science, Kokushikan University, Tama, Japan.
Tatsumi
T
Kusakabe
Laboratory of Veterinary Anatomy and Cell Biology, Faculty of Agriculture, Iwate University, Morioka, Japan. Electronic address: yyoshio@iwate-u.ac.jp.
Yoshio
Y
Yamamoto
D000818:Animals; D002344:Carotid Body / Q000166:cytology / Q000378:metabolism*; D059290:Dopaminergic Neurons / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D017208:Rats, Wistar; D017448:Receptors, Dopamine D2 / Q000378:metabolism*
D017448:Receptors, Dopamine D2
Carotid body; Chemoreceptor; Dopamine D2 receptor; Glomus cell; Rat