In a previous study, we have shown that endothelin-1 (ET-1) activates phospholipase D independently from protein kinase C in osteoblast-like MC3T3- E1 cells. It is well recognized that phosphatidylcholine hydrolysis by phospholipase D generates phosphatidic acid, which can be further degraded by phosphatidic acid phosphohydrolase to diacylglycerol. In the present study, we investigated the role of phospholipase D activation in ET-1-induced arachidonic acid release and prostaglandin E2 (PGE2) synthesis in osteoblast-like MC3T3-E1 cells. ET-1 stimulated arachidonic acid release dose-dependently in the range between 0.1 nM and 0.1 μM. Propranolol, an inhibitor of phospatidic acid phosphohydrolase, significantly inhibited the ET-1-induced arachidonic acid release in a dose-dependent manner as well as the ET-1-induced diacylglycerol formation, 1,6-bis- (cyclohexyloxyminocarbonylamino)-hexane (RHC-80267), an inhibitor of diacylglycerol lipase, significantly suppressed the ET-1-induced arachidonic acid release. The pretreatment with propranolol and RHC-80267 also inhibited the ET-1-induced PGE2 synthesis. These results strongly suggest that phosphatidylcholine hydrolysis by phospholipase D is involved in the arachidonic acid release induced by ET-1 in osteoblast-like cells.
|ジャーナル||Journal of Cellular Biochemistry|
|出版ステータス||Published - 01-03-1997|
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