title: Subunit profiling and functional characteristics of acetylcholine receptors in GT1-7 cells.
abstract: GnRH neurons form a final common pathway for the central regulation of reproduction. Although the involvement of acetylcholine in GnRH secretion has been reported, direct effects of acetylcholine and expression profiles of acetylcholine receptors (AChRs) still remain to be studied. Using immortalized GnRH neurons (GT1-7 cells), we analyzed molecular expression and functionality of AChRs. Expression of the mRNAs were identified in the order α7 > β2 = β1 ≧ α4 ≧ α5 = β4 = δ > α3 for nicotinic acetylcholine receptor (nAChR) subunits and m4 > m2 for muscarinic acetylcholine receptor (mAChR) subtypes. Furthermore, this study revealed that α7 nAChRs contributed to Ca2+influx and GnRH release and that m2 and m4 mAChRs inhibited forskolin-induced cAMP production and isobutylmethylxanthine-induced GnRH secretion. These findings demonstrate the molecular profiles of AChRs, which directly contribute to GnRH secretion in GT1-7 cells, and provide one possible regulatory action of acetylcholine in GnRH neurons.
authors.affiliation: Department of Anatomy and Neurobiology, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo, 113-8602, Japan.|Department of Life Science, International Christian University, 3-10-2, Osawa, Mitaka-shi, Tokyo, 181-8585, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Arai
authors.affiliation: Department of Anatomy and Neurobiology, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo, 113-8602, Japan. hirotaka@nms.ac.jp.
authors.forename: Hirotaka
authors.identifier: http://orcid.org/0000-0003-2044-316X
authors.initials: H
authors.lastname: Ishii
authors.affiliation: Department of Life Science, International Christian University, 3-10-2, Osawa, Mitaka-shi, Tokyo, 181-8585, Japan.
authors.forename: Makito
authors.initials: M
authors.lastname: Kobayashi
authors.affiliation: Department of Anatomy and Neurobiology, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo, 113-8602, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ozawa
mesh_terms: D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D005260:Female; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000378:metabolism; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism; D011950:Receptors, Cholinergic / Q000378:metabolism*; D011978:Receptors, Nicotinic / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D011950:Receptors, Cholinergic; D011978:Receptors, Nicotinic; D000109:Acetylcholine
keywords: Acetylcholine; Acetylcholine receptors; GT1-7; GnRH neurons; Gonadotropin-releasing hormone