Further evidence against the validity of using an ADP-removing enzyme system (CP/CPK) for demonstrating the role of secreted ADP in platelet activation
| Autor: | Paul D. Chamberlain, Barbara Nunn |
|---|---|
| Rok vydání: | 1983 |
| Předmět: |
Agonist
Blood Platelets medicine.medical_specialty Phosphocreatine Platelet Aggregation medicine.drug_class Stimulation In Vitro Techniques Creatine Thromboxane receptor chemistry.chemical_compound Mice Enzyme system Internal medicine medicine Extracellular Animals Platelet Creatine Kinase biology Chemistry fungi Hematology Prostaglandin Endoperoxides Synthetic Adenosine Diphosphate Endocrinology 15-Hydroxy-11 alpha 9 alpha-(epoxymethano)prosta-5 13-dienoic Acid biology.protein Creatine kinase |
| Zdroj: | Thrombosis research. 30(1) |
| ISSN: | 0049-3848 |
| Popis: | The ADP-removing enzyme system creatine phosphate-creatine phosphokinase (CP/CPK) selectively inhibited primary aggregation in response to the thromboxane receptor agonist, U46619, in mouse aspirin-treated platelet-rich plasma. Inhibition by CP/CPK has become accepted as evidence for mediation by secreted ADP, yet primary aggregation is not usually attributed to secreted ADP. Hence these results throw doubt on the assumed mechanism by which CP/CPK inhibits aggregation. The possibility that such inhibition was due to removal of extracellular ADP released prior to platelet stimulation and exerting a potentiating influence was investigated. This explanation appeared unlikely as further additions of creatine phosphokinase to platelet-rich plasma preincubated with CP/CPK caused further inhibition of primary aggregation. Moreover, low concentrations of CP/CPK that reduced responsiveness to U46619 had no effect on collagen-induced aggregation, which ADP is known to potentiate. The evidence presented is consistent with CP/CPK exerting a direct inhibitory effect on platelet membranes and so inhibiting a facet of platelet aggregation not mediated by secreted ADP. These data support the conclusion of a previous study (Huang, E.M. and Detwiler,T.C., J. Lab. Clin. Med.,95, 59–68,1980) that inhibition by CP/CPK cannot be taken as evidence for the involvement of secreted ADP. |
| Databáze: | OpenAIRE |
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