title: Study on action mode of sphingosine 1-phosphate in rat hepatocytes.
abstract: Sphingosine-1-phosphate (S1P) acts on a set of G protein-coupled receptors in the plasma membrane and also as a second messenger in certain cell types. There are two possible pathways to mobilize intracellular Ca(2+) concentration by S1P. One is through phospholipase C, and the other is through intracellular Ca(2+) channels operated by S1P. The Mn(2+) quenching method was applied to elucidate the action mode of S1P-induced Ca(2+) mobilization in rat hepatocytes. In permeabilized hepatocytes, inositol trisphosphate induced Mn(2+) quenching, and it was blocked by heparin. However, S1P did not induce Mn(2+) quenching. Results suggest that S1P did not mobilize Ca(2+) through intracellular Ca(2+) channels.
authors.affiliation: Laboratory of Pharmacology, College of Pharmacy, Pusan National University, Busan, Republic of Korea.
authors.forename: Young-Jin
authors.initials: YJ
authors.lastname: Im
authors.forename: Dong-Soon
authors.initials: DS
authors.lastname: Im
authors.forename: Yun-Kyung
authors.initials: YK
authors.lastname: Lee
authors.forename: Eun-Hee
authors.initials: EH
authors.lastname: Lee
authors.forename: Koichi
authors.initials: K
authors.lastname: Sato
authors.forename: Hideaki
authors.initials: H
authors.lastname: Tomura
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Katada
authors.forename: Michio
authors.initials: M
authors.lastname: Ui
authors.forename: Fumikazu
authors.initials: F
authors.lastname: Okajima
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D018929:Cell Culture Techniques; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D006493:Heparin / Q000494:pharmacology; D022781:Hepatocytes / Q000187:drug effects*; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D007700:Kinetics; D008246:Lysophospholipids / Q000494:pharmacology*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D015290:Second Messenger Systems / Q000187:drug effects*; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D008246:Lysophospholipids; C060506:sphingosine 1-phosphate; D015544:Inositol 1,4,5-Trisphosphate; D006493:Heparin; D013110:Sphingosine; D002118:Calcium