The Influence of Epinephrine on Washed Human Platelets: Shape Change and Protein Phosphorylation
- 1 January 1984
- journal article
- research article
- Published by Taylor & Francis in Journal of Receptor Research
- Vol. 4 (1-6), 537-556
- https://doi.org/10.3109/10799898409042572
Abstract
Protein phosphorylation is an important regulator of the properties or functions of many proteins and is associated with the platelet activation response to a number of chemically and functionally different agents such as thrombin, plateletactivating factor, serotonin and collagen. The physiological responses of platelets to these agents are similar, and the common intracellular messenger for activation is an elevated concentration of calcium. Platelets possess alpha-2-receptors, and treatment with epinephrine produces an elevation in platelet cytosolic free calcium concentrations. Methods are described for studying hormone sensitive shape change and protein phosphorylation in washed human platelets. Epinephrine induces platelet shape change, and this process is independent of extracellular calcium. Treatment of [32P]-orthophosphate-labelled platelets with epinephrine produces an increase in 32P-incorporation into two platelet proteins with molecular weights of 47000 and 20000. This phosphorylation response is both dose and time dependent. Extracellular calcium is not absolutely essential for epinephrine-induced phosphorylation, but does enhance the maximum levels of 32P-incorporation. Epinephrine sensitive phosphorylation is completely inhibited following pretreatment with verapamil or nitrendipine. Shape change in response to epinephrine occurs in the absence of enhanced protein phosphorylation. The data suggest that epinephrine mobilizes intracellular calcium, and induces platelet shape change and phosphorylation responses characteristic of platelet activation.Keywords
This publication has 17 references indexed in Scilit:
- Excitatory and inhibitory modulation of intracellular free calcium in human platelets by hormones and drugsEuropean Journal of Pharmacology, 1983
- [4] Measurement of hormone-stimulated protein phosphorylation in intact cellsMethods in Enzymology, 1983
- Phosphorylation of the same specific protein during amylase release evoked by beta-adrenergic or cholinergic agonists in rat and mouse parotid glands.Proceedings of the National Academy of Sciences, 1981
- Interaction of Ca2+ and protein phosphorylation in the rabbit platelet release reaction.JCI Insight, 1980
- A study of protein phosphorylation in shape change and Ca++-dependent serotonin release by blood plateletsCell, 1979
- Effects of collagen, ionophore A23187 and prostaglandin E1 on the phosphorylation of specific proteins in blood plateletsBiochemical Journal, 1979
- A rapid method for the measurement of [γ-32P]ATP specific radioactivity in tissue extracts and its application to the study of 32Pi uptake in perfused rat heartAnalytical Biochemistry, 1976
- Cleavage of Structural Proteins during the Assembly of the Head of Bacteriophage T4Nature, 1970
- A convenient method of preparing polyacrylamide gels for liquid scintillation spectrometryAnalytical Biochemistry, 1968
- THE RELATIONSHIP OF EPINEPHRINE AND GLUCAGON TO LIVER PHOSPHORYLASEPublished by Elsevier ,1956