TY - JOUR
T1 - Enhancement of collagen-induced phosphoinositide turnover by thromboxane A2 analogue through Ca2+ mobilization in human platelets
AU - Kaibuchi, Kozo
AU - Tsuda, Terutaka
AU - Kikuchi, Akira
AU - Tanimoto, Tetsuji
AU - Takai, Yoshimi
N1 - Funding Information:
The secretariaal ssistanceo f Miss J. Yamaguchi is greatly acknowledged.T his investigationw as supported in part by researchg rants from the ScientificR esearchF und of the Ministry of Education, Sciencea nd Culture, Japan (1985),t he Naito Foundation (1984)a nd the Yamanouchi Foundation for Researcho n Metabolic Disorders (1984).
PY - 1985/11/11
Y1 - 1985/11/11
N2 - In human washed platelets, collagen-induced phosphoinositide turnover was inhibited by indomethacin, an inhibitor of thromboxane A2 (TXA2) formation, particularly at lower doses of collagen. This inhibition was counteracted by the addition of 9,11-epithio-11,12-methano-TXA2 (STA2), a stable analogue of TXA2 as well as by the Ca2+ ionophore A23187. STA2 and A23187 did not stimulate phosphoinositide turnover markedly, but significantly increased cytoplasmic free Ca2+ concentrations. The actions of STA2 were blocked by 13-azaprostanoic acid, a TXA2 receptor antagonist. These results suggest that TXA2 is generated during the action of collagen and increases cytoplasmic free Ca2+ which then stimulates phosphoinositide turnover in cooperation with collagen.
AB - In human washed platelets, collagen-induced phosphoinositide turnover was inhibited by indomethacin, an inhibitor of thromboxane A2 (TXA2) formation, particularly at lower doses of collagen. This inhibition was counteracted by the addition of 9,11-epithio-11,12-methano-TXA2 (STA2), a stable analogue of TXA2 as well as by the Ca2+ ionophore A23187. STA2 and A23187 did not stimulate phosphoinositide turnover markedly, but significantly increased cytoplasmic free Ca2+ concentrations. The actions of STA2 were blocked by 13-azaprostanoic acid, a TXA2 receptor antagonist. These results suggest that TXA2 is generated during the action of collagen and increases cytoplasmic free Ca2+ which then stimulates phosphoinositide turnover in cooperation with collagen.
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U2 - 10.1016/0014-5793(85)80052-1
DO - 10.1016/0014-5793(85)80052-1
M3 - Article
C2 - 2996935
AN - SCOPUS:0022351680
VL - 192
SP - 104
EP - 108
JO - FEBS Letters
JF - FEBS Letters
SN - 0014-5793
IS - 1
ER -