Adrenaline potentiates PI 3‐kinase in platelets stimulated with thrombin and SFRLLN: role of secreted ADP

[摘要]

Adrenaline significantly potentiated late thrombin- and SFRLLN-induced PtdIns(3,4)P₂ production. Furthermore, the potentiating effect of adrenaline on thrombin-induced PtdIns(3,4)P₂ production was independent on secreted ADP, whereas, the effect of adrenaline on SFRLLN-induced PtdIns(3,4)P₂ production was completely dependent of secreted ADP. However, the ADP-dependent accumulation of PtdIns(3,4)P₂ was not required for irreversible platelet aggregation induced by SFRLLN in the presence of adrenaline. It is concluded that adrenaline can replace secreted ADP to potentiate PtdIns(3,4)P₂ production in thrombin-stimulated but not in SFRLLN-stimulated platelets, thus demonstrating a qualitative difference between platelet stimulation by thrombin and the thrombin receptor activating peptide SFRLLN.

[学科分类] 生物化学/生物物理

[关键词] Adrenaline;Phosphoinositide 3-kinase;ACD;acid citrate dextrose;CP;creatine phosphate;CPK;creatine phosphokinase;GFP;gel-filtered platelets;GroPIns;glycerophosphoinositols;HPLC;high performance liquid chromatography;PI3K;phosphoinositide 3-kinase;PtdIns;phosphatidylinositol;PtdIns(3;4)P2;phosphatidylinositol 3;4-bisphosphate;PtdIns(4;5)P2;phosphatidylinositol 4;5-bisphosphate;PtdIns(3;4;5)P3;phosphatidylinositol 3;4;5-trisphosphate;PRP;platelet-rich plasma;TLC;thin layer chromatography