Abstract
In the present study, we examined the effect of angiotensin II (Ang II) on phosphatidylcholine-hydrolyzing phospholipase D activity in subcultured rat aortic smooth muscle cells (SMC). Ang II dose-dependently stimulated the formation of choline and inositol phosphates. The effect of Ang II on the formation of inositol phosphates (EC50 was 0.249 ± 0.091 nM) was more potent than that on the formation of choline (EC50 was 2.39 ± 1.29 nM). A combination of Ang II and 12-O-tetradecanoylphorbol-13-acetate (TPA), an activator of protein kinase C, additively stimulated the formation of choline. Staurosporine, an inhibitor of protein kinases, inhibited the TPA-induced formation of choline, but had little effect on the Ang II-induced choline formation. Ang II stimulated Ca2+ influx from extracellular space time- and dose-dependently. The depletion of extracellular Ca2+ by (ethylenebis(oxyethylenenitrilo))tetraacetic acid (EGTA) significantly reduced the Ang II-induced formation of choline. Genistein and tyrphostin, protein tyrosine kinase inhibitors, significantly suppressed the Ang II-induced Ca2+ influx. Genistein and tyrphostin also suppressed the Ang II-induced formation of choline. These results suggest that Ang II stimulates phosphatidylcholine-hydrolyzing phospholipase D due to Ca2+ influx from the extracellular space in rat aortic SMC, and that protein tyrosine kinase is involved in the Ang II-induced Ca2+ influx, resulting in the promotion of phosphatidylcholine hydrolysis.
| Original language | English |
|---|---|
| Pages (from-to) | 119-127 |
| Number of pages | 9 |
| Journal | Atherosclerosis |
| Volume | 121 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 01-03-1996 |
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All Science Journal Classification (ASJC) codes
- Cardiology and Cardiovascular Medicine
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Tyrosine kinase is involved in angiotensin II-stimulated phospholipase D activation in aortic smooth muscle cells : Function of Ca2+ influx. / Suzuki, Atsushi; Shinoda, Junji; Oiso, Yutaka; Kozawa, Osamu.
In: Atherosclerosis, Vol. 121, No. 1, 01.03.1996, p. 119-127.Research output: Contribution to journal › Article
TY - JOUR
T1 - Tyrosine kinase is involved in angiotensin II-stimulated phospholipase D activation in aortic smooth muscle cells
T2 - Function of Ca2+ influx
AU - Suzuki, Atsushi
AU - Shinoda, Junji
AU - Oiso, Yutaka
AU - Kozawa, Osamu
PY - 1996/3/1
Y1 - 1996/3/1
N2 - In the present study, we examined the effect of angiotensin II (Ang II) on phosphatidylcholine-hydrolyzing phospholipase D activity in subcultured rat aortic smooth muscle cells (SMC). Ang II dose-dependently stimulated the formation of choline and inositol phosphates. The effect of Ang II on the formation of inositol phosphates (EC50 was 0.249 ± 0.091 nM) was more potent than that on the formation of choline (EC50 was 2.39 ± 1.29 nM). A combination of Ang II and 12-O-tetradecanoylphorbol-13-acetate (TPA), an activator of protein kinase C, additively stimulated the formation of choline. Staurosporine, an inhibitor of protein kinases, inhibited the TPA-induced formation of choline, but had little effect on the Ang II-induced choline formation. Ang II stimulated Ca2+ influx from extracellular space time- and dose-dependently. The depletion of extracellular Ca2+ by (ethylenebis(oxyethylenenitrilo))tetraacetic acid (EGTA) significantly reduced the Ang II-induced formation of choline. Genistein and tyrphostin, protein tyrosine kinase inhibitors, significantly suppressed the Ang II-induced Ca2+ influx. Genistein and tyrphostin also suppressed the Ang II-induced formation of choline. These results suggest that Ang II stimulates phosphatidylcholine-hydrolyzing phospholipase D due to Ca2+ influx from the extracellular space in rat aortic SMC, and that protein tyrosine kinase is involved in the Ang II-induced Ca2+ influx, resulting in the promotion of phosphatidylcholine hydrolysis.
AB - In the present study, we examined the effect of angiotensin II (Ang II) on phosphatidylcholine-hydrolyzing phospholipase D activity in subcultured rat aortic smooth muscle cells (SMC). Ang II dose-dependently stimulated the formation of choline and inositol phosphates. The effect of Ang II on the formation of inositol phosphates (EC50 was 0.249 ± 0.091 nM) was more potent than that on the formation of choline (EC50 was 2.39 ± 1.29 nM). A combination of Ang II and 12-O-tetradecanoylphorbol-13-acetate (TPA), an activator of protein kinase C, additively stimulated the formation of choline. Staurosporine, an inhibitor of protein kinases, inhibited the TPA-induced formation of choline, but had little effect on the Ang II-induced choline formation. Ang II stimulated Ca2+ influx from extracellular space time- and dose-dependently. The depletion of extracellular Ca2+ by (ethylenebis(oxyethylenenitrilo))tetraacetic acid (EGTA) significantly reduced the Ang II-induced formation of choline. Genistein and tyrphostin, protein tyrosine kinase inhibitors, significantly suppressed the Ang II-induced Ca2+ influx. Genistein and tyrphostin also suppressed the Ang II-induced formation of choline. These results suggest that Ang II stimulates phosphatidylcholine-hydrolyzing phospholipase D due to Ca2+ influx from the extracellular space in rat aortic SMC, and that protein tyrosine kinase is involved in the Ang II-induced Ca2+ influx, resulting in the promotion of phosphatidylcholine hydrolysis.
UR - http://www.scopus.com/inward/record.url?scp=0030025752&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030025752&partnerID=8YFLogxK
U2 - 10.1016/0021-9150(95)05708-0
DO - 10.1016/0021-9150(95)05708-0
M3 - Article
C2 - 8678916
AN - SCOPUS:0030025752
VL - 121
SP - 119
EP - 127
JO - Atherosclerosis
JF - Atherosclerosis
SN - 0021-9150
IS - 1
ER -