The relative importance of inositol 1,4,5-trisphosphate, 1,2-diacylglycerol and phosphatidic acid in mediating human platelet activation by thrombin
Thrombin-induced platelet activation can be correlated with formation of three potential bioactive agents (i.e. , second messengers), namely, inositol 1,4,5-trisphosphate, 1,2-diacylglycerol and phosphatidic acid. The present article reviews the relative importance of these three second messengers. It is suggested that both 1,2-diacylglycerol and phosphatidic acid may be of importance in activating protein kinase C in platelets, and that inositol 1,4,5-trisphosphate and possibly lysophosphatidic acid, may be of importance in mobilizing Ca++. It is concluded that thrombin-induced platelet activation occurs through the synergistic interaction of Ca++ and protein kinase C activation.
KeywordsHuman Platelet Phosphatidic Acid Pancreatic Acinar Cell Lysophosphatidic Acid Release Reaction
Unable to display preview. Download preview PDF.
- LAPETINA, E.G. & SIESS, W. (1983). The role of phospholipase C in platelet responses. Life Sci., 33, 1011–1018.Google Scholar
- SIESS, W., WEBER, P.C. & LAPETINA, E.G. (1984). Activation of phospholipase C is dissociated from arachidonate metabolism during shape change induced by thrombin or platelet-activating factor; epinephrine does not induce phospholipase C activation or platelet shape change. J. biol. Chem. (in press).Google Scholar
- WATSON, S.P., McCONNELL, R.T. & LAPETINA, E.G. (1984b). The rapid formation of inositol phosphates in human platelets by thrombin is inhibited by prostacyclin. J. biol. Chem. (in press).Google Scholar