Phosphoinositide metabolism in resting and thrombin‐stimulated human platelets Evidence against metabolic heterogeneity

FEBS Letters

Aarbakke, Grethe M.¹  Verhoeven, Adrie J.M.¹  Tysnes, Ole-Bjørn¹  Holmsen, Holm¹ 

[1] Department of Biochemistry, University of Bergen, Årstadveien 19, N-5000 Bergen, Norway

关键词: Phospholipid metabolism;    Inositol phospholipid;    Thrombin;    (Human platelet);    PI;    phosphatidylinositol;    PIP;    phosphatidylinositol;    4-phosphate;    PIP2;    phosphatidylinositol 4;    5-bisphosphate;    PA;    phosphatidic acid;    GroPI;    diacylated phosphatidylinositol;   

DOI  :  10.1016/0014-5793(87)81020-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The specific radioactivity of the phosphodiester and phosphomonoester moieties of the phosphoinositides was determined in resting and thrombin-stimulated platelets that were prelabelled with [³²P] P_i. In the unstimulated cells, the specific radioactivity of the monoester phosphates of PIP and PIP₂ was similar. Both prolonged incubation at 37°C and upon stimulation with 0.5 U/ml of thrombin, the specific radioactivity of the monoester phosphates decreased 10–15% in both polyphosphoinositides. In the unstimulated cells, the specific radioactivity of the diester phosphates was similar in PI, PIP and PIP₂ but amounted only to 3% of the activity of the monoester groups. Prolonged incubation of the unstimulated cells as well as stimulation with thrombin induced a similar 5–6 fold increase in specific radioactivity of the diester phosphate of PI, PIP and PIP₂. The results indicate that the phosphoinositides in both resting and thrombin-stimulated platelets exist in a metabolically homogeneous pool.

【 授权许可】

Unknown