title: 5-hydroxytryptamine synthesis in HL-1 cells and neonatal rat cardiocytes.
abstract: Some reports showed that serotonergic system might have existed and that 5-hydroxytryptamine (5-HT) was detected in the hamster heart. The source of 5-HT in the heart, however, remains to be fully elucidated. So the present study was designed to define serotonergic system and to clarify which cell could produce 5-HT in the heart. As a result, 5-HT was detected in homogenates of HL-1 cardiomyocytes by high performance liquid chromatography with fluorescence detection, but not in those of neonatal rat non-cardiomyocytes (NMCs). And TPH and AADC mRNAs were expressed in HL-1 cardiomyocytes and neonatal rat cardiomyocytes (MCs), not in NMCs. mRNAs of 5-HT(2A) receptor were detected in both MCs and NMCs, and those of 5-HT(2B) receptor in NMCs. These findings definitively demonstrate that 5-HT is secreted from the myocytes of the heart and strongly implied that 5-HT might play a certain role in cardiac physiology.
authors.affiliation: Department of Pharmacology I, Jikei University School of Medicine, Minato-ku, Tokyo 105-8461, Japan. ikedak@jikei.ac.jp
authors.forename: Keiichi
authors.initials: K
authors.lastname: Ikeda
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Tojo
authors.forename: Chikara
authors.initials: C
authors.lastname: Otsubo
authors.forename: Takashi
authors.initials: T
authors.lastname: Udagawa
authors.forename: Kensuke
authors.initials: K
authors.lastname: Kumazawa
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ishikawa
authors.forename: Goro
authors.initials: G
authors.lastname: Tokudome
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Hosoya
authors.forename: Naoko
authors.initials: N
authors.lastname: Tajima
authors.forename: William C
authors.initials: WC
authors.lastname: Claycomb
authors.forename: Kazuwa
authors.initials: K
authors.lastname: Nakao
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kawamura
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002460:Cell Line; D002478:Cells, Cultured; D032383:Myocytes, Cardiac / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000096:biosynthesis*
chemical_list: D012701:Serotonin