Study on action mode of sphingosine 1-phosphate in rat hepatocytes.
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.
Im
Young-Jin
YJ
Laboratory of Pharmacology, College of Pharmacy, Pusan National University, Busan, Republic of Korea.
Im
Dong-Soon
DS
Lee
Yun-Kyung
YK
Lee
Eun-Hee
EH
Sato
Koichi
K
Tomura
Hideaki
H
Katada
Toshiaki
T
Ui
Michio
M
Okajima
Fumikazu
F
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
D008246:Lysophospholipids; C060506:sphingosine 1-phosphate; D015544:Inositol 1,4,5-Trisphosphate; D006493:Heparin; D013110:Sphingosine; D002118:Calcium