We previously reported that prostaglandin F2α (PGF2α) induces Ca2+ influx from the extracellular space via protein tyrosine kinase in osteoblast-like MC3T3-E1 cells and that PGF2α stimulates phosphatidylcholine-hydrolyzing phospholipase D in these cells (6, 12). In this study, we examined the relationship between the tyrosine kinase-regulated Ca2+ influx by PGF2α and the activation of phospholipase D in MC3T3-E1 cells. The depletion of extracellular Ca2+ by [ethylenebis(oxyethylenenitrilo)]tetraacetic acid (EGTA) markedly reduced the PGF2α-induced formation of choline. Genistein, an inhibitor of protein tyrosine kinases, which by itself had little effect on choline formation, significantly suppressed the formation of choline induced by PGF2α in a dose-dependent manner. Tyrphostin, an inhibitor of protein tyrosine kinases chemically distinct from genistein, also suppressed the PGF2α-induced formation of choline. Sodium orthovanadate, an inhibitor of protein tyrosine phosphatases, significantly enhanced the PGF2α-induced formation of choline. These results strongly suggest that the phospholipase D activation by PGF2α is dependent on extracellular Ca2+ in osteoblast-like cells and that protein tyrosine kinase is involved in the activation of phospholipase D.
|Number of pages||5|
|Journal||Prostaglandins, Leukotrienes and Essential Fatty Acids|
|Publication status||Published - 05-1995|
All Science Journal Classification (ASJC) codes
- Clinical Biochemistry
- Cell Biology