Sphingosine 1-Phosphate Stimulates Insulin Secretion in HIT-T 15 Cells and Mouse Islets.
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Accession number;00A0626830
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| Title;Sphingosine 1-Phosphate Stimulates Insulin Secretion in HIT-T 15 Cells and Mouse Islets. |
| Author;
SHIMIZU H
(Gunma Univ. School Of Medicine, Gunma, Jpn)
OKAJIMA F
(Gunma Univ., Gunma, Jpn)
KIMURA T
(Gunma Univ. School Of Medicine, Gunma, Jpn)
OHTANI K
(Gunma Univ. School Of Medicine, Gunma, Jpn)
TSUCHIYA T
(Gunma Univ. School Of Medicine, Gunma, Jpn)
KUWABARA H
(Gunma Univ. School Of Medicine, Gunma, Jpn)
TOMURA H
(Gunma Univ., Gunma, Jpn)
SATO K
(Gunma Univ., Gunma, Jpn)
MORI M
(Gunma Univ. School Of Medicine, Gunma, Jpn)
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Journal Title;Endocr J
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Journal Code:F0625A
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ISSN:0918-8959
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VOL.47;NO.3;PAGE.261-269(2000)
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| Figure&Table&Reference;FIG.6, TBL.1, REF.37 |
| Pub. Country;Japan |
| Language;English |
| Abstract;Sphingosine is involved in the regulation of cellular processes as a second messenger in various kinds of cells. Since the possible involvement of sphingosine has not been investigated in pancreatic .BETA.-cells, we determined the expression of putative sphingosine 1-phosphate (S1P) receptors and the effect of sphingosine on pancreatic .BETA.-cell function using a clonal Hamster .BETA.-cell line, HIT-T 15 cells and isolated mouse islets. We showed the expression of putative S1P receptors, Edg-3 and AGR16/H218 in HIT-T 15 cells. Ten and 20 .MU.M S1P significantly stimulated insulin secretion for 10 minutes in HIT-T 15 cells. Ten .MU.M S1P significantly increased insulin secretion from isolated mouse islets. Ten .MU.M S1P obviously increased intracellular Ca2+ concentration ([Ca2+]i). Fifty nM nifedipine did not affect the S1P stimulation of insulin secretion in HIT-T 15 cells. Two .MU.M U73122 (phospholipase C inhibitor) completely deleted 10 .MU.M S1P-induced stimulation of insulin secretion for 10 minutes, but U73343 (an inactive analogue of U73122) did not. S1P dose-dependently inhibited intracellular cyclic AMP levels. Pretreatment with 100 ng/ml pertussis toxin (PTX) partially, but significantly attenuated an increase of insulin secretion by 10 .MU.M S1P. These data suggested that PTX-sensitive G-protein-dependent pathway may, at least in part, be involved in an increase of non-glucose stimulated insulin secretion by S1P through the activation of phospholipase C- Ca2+ system. (author abst.) |
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